Genotypic differences observed among individuals in a population.
A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.
Nonrandom association of linked genes. This is the tendency of the alleles of two separate but already linked loci to be found together more frequently than would be expected by chance alone.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
The relationships of groups of organisms as reflected by their genetic makeup.
Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)
A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).
Genetic loci associated with a QUANTITATIVE TRAIT.
The analysis of a sequence such as a region of a chromosome, a haplotype, a gene, or an allele for its involvement in controlling the phenotype of a specific trait, metabolic pathway, or disease.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
An analysis comparing the allele frequencies of all available (or a whole GENOME representative set of) polymorphic markers in unrelated patients with a specific symptom or disease condition, and those of healthy controls to identify markers associated with a specific disease or condition.
Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.
A characteristic showing quantitative inheritance such as SKIN PIGMENTATION in humans. (From A Dictionary of Genetics, 4th ed)
A branch of genetics which deals with the genetic variability in individual responses to drugs and drug metabolism (BIOTRANSFORMATION).
Stretches of genomic DNA that exist in different multiples between individuals. Many copy number variations have been associated with susceptibility or resistance to disease.
Any method used for determining the location of and relative distances between genes on a chromosome.
The change in gene frequency in a population due to migration of gametes or individuals (ANIMAL MIGRATION) across population barriers. In contrast, in GENETIC DRIFT the cause of gene frequency changes are not a result of population or gamete movement.
A mutation named with the blend of insertion and deletion. It refers to a length difference between two ALLELES where it is unknowable if the difference was originally caused by a SEQUENCE INSERTION or by a SEQUENCE DELETION. If the number of nucleotides in the insertion/deletion is not divisible by three, and it occurs in a protein coding region, it is also a FRAMESHIFT MUTATION.
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
Individuals whose ancestral origins are in the continent of Europe.
An individual having different alleles at one or more loci regarding a specific character.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
The mating of plants or non-human animals which are closely related genetically.
The fluctuation of the ALLELE FREQUENCY from one generation to the next.
Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.
A field of study concerned with the principles and processes governing the geographic distributions of genealogical lineages, especially those within and among closely related species. (Avise, J.C., Phylogeography: The History and Formation of Species. Harvard University Press, 2000)
The external elements and conditions which surround, influence, and affect the life and development of an organism or population.
The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.
An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.
A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.
The systematic study of the complete DNA sequences (GENOME) of organisms.
Technique that utilizes low-stringency polymerase chain reaction (PCR) amplification with single primers of arbitrary sequence to generate strain-specific arrays of anonymous DNA fragments. RAPD technique may be used to determine taxonomic identity, assess kinship relationships, analyze mixed genome samples, and create specific probes.
A country spanning from central Asia to the Pacific Ocean.
The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.
The different ways GENES and their ALLELES interact during the transmission of genetic traits that effect the outcome of GENE EXPRESSION.
Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.
Number of individuals in a population relative to space.
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
Mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components.
A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)
A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.
An individual in which both alleles at a given locus are identical.
The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.
The total process by which organisms produce offspring. (Stedman, 25th ed)
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.
Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
A plant genus of the family Phrymaceae. Members contain 6-geranylflavanones and mimulone.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
The combined effects of genotypes and environmental factors together on phenotypic characteristics.
The total number of individuals inhabiting a particular region or area.
The detection of RESTRICTION FRAGMENT LENGTH POLYMORPHISMS by selective PCR amplification of restriction fragments derived from genomic DNA followed by electrophoretic analysis of the amplified restriction fragments.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
A phenotypic outcome (physical characteristic or disease predisposition) that is determined by more than one gene. Polygenic refers to those determined by many genes, while oligogenic refers to those determined by a few genes.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.
Enzyme that catalyzes the movement of a methyl group from S-adenosylmethionone to a catechol or a catecholamine.
Databases devoted to knowledge about specific genes and gene products.
A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
Contiguous large-scale (1000-400,000 basepairs) differences in the genomic DNA between individuals, due to SEQUENCE DELETION; SEQUENCE INSERTION; or SEQUENCE INVERSION.
Methods used to determine individuals' specific ALLELES or SNPS (single nucleotide polymorphisms).
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.
An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.
Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.
The biological objects that contain genetic information and that are involved in transmitting genetically encoded traits from one organism to another.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Elements of limited time intervals, contributing to particular results or situations.
Deoxyribonucleic acid that makes up the genetic material of plants.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
The genetic complement of a plant (PLANTS) as represented in its DNA.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The selection or choice of sexual partner in animals. Often this reproductive preference is based on traits in the potential mate, such as coloration, size, or behavioral boldness. If the chosen ones are genetically different from the rejected ones, then NATURAL SELECTION is occurring.
The capability of an organism to survive and reproduce. The phenotypic expression of the genotype in a particular environment determines how genetically fit an organism will be.
Individuals whose ancestral origins are in the continent of Africa.
The physical measurements of a body.
Tracts of land completely surrounded by water.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.
The splitting of an ancestral species into daughter species that coexist in time (King, Dictionary of Genetics, 6th ed). Causal factors may include geographic isolation, HABITAT geometry, migration, REPRODUCTIVE ISOLATION, random GENETIC DRIFT and MUTATION.
Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.
Computer-based representation of physical systems and phenomena such as chemical processes.
Animals produced by the mating of progeny over multiple generations. The resultant strain of animals is virtually identical genotypically. Highly inbred animal lines allow the study of certain traits in a relatively pure form. (Segen, Dictionary of Modern Medicine, 1992)
A phenomenon in which multiple and diverse phenotypic outcomes are influenced by a single gene (or single gene product.)
Statistical interpretation and description of a population with reference to distribution, composition, or structure.
Biochemical identification of mutational changes in a nucleotide sequence.
The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.
A coordinated international effort to identify and catalog patterns of linked variations (HAPLOTYPES) found in the human genome across the entire human population.
Sexual activities of animals.
The probability that an event will occur. It encompasses a variety of measures of the probability of a generally unfavorable outcome.
The branch of science concerned with the interrelationship of organisms and their ENVIRONMENT, especially as manifested by natural cycles and rhythms, community development and structure, interactions between different kinds of organisms, geographic distributions, and population alterations. (Webster's, 3d ed)
A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen trees mainly in temperate climates.
Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.
Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.
The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.
Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.
The functional hereditary units of PLANTS.
The reproductive organs of plants.
Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.
The capacity to conceive or to induce conception. It may refer to either the male or female.
Techniques of nucleotide sequence analysis that increase the range, complexity, sensitivity, and accuracy of results by greatly increasing the scale of operations and thus the number of nucleotides, and the number of copies of each nucleotide sequenced. The sequencing may be done by analysis of the synthesis or ligation products, hybridization to preexisting sequences, etc.
The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.
Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.
Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.
The functional hereditary units of INSECTS.
Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.
Individuals classified according to their sex, racial origin, religion, common place of living, financial or social status, or some other cultural or behavioral attribute. (UMLS, 2003)
Tandem arrays of moderately repetitive, short (10-60 bases) DNA sequences which are found dispersed throughout the GENOME, at the ends of chromosomes (TELOMERES), and clustered near telomeres. Their degree of repetition is two to several hundred at each locus. Loci number in the thousands but each locus shows a distinctive repeat unit.
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of serotonergic neurons. They are different than SEROTONIN RECEPTORS, which signal cellular responses to SEROTONIN. They remove SEROTONIN from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. Regulates signal amplitude and duration at serotonergic synapses and is the site of action of the SEROTONIN UPTAKE INHIBITORS.
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
Cytochromes of the b group that have alpha-band absorption of 563-564 nm. They occur as subunits in MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III.
The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.
The protection, preservation, restoration, and rational use of all resources in the total environment.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).
Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.
The ratio of two odds. The exposure-odds ratio for case control data is the ratio of the odds in favor of exposure among cases to the odds in favor of exposure among noncases. The disease-odds ratio for a cohort or cross section is the ratio of the odds in favor of disease among the exposed to the odds in favor of disease among the unexposed. The prevalence-odds ratio refers to an odds ratio derived cross-sectionally from studies of prevalent cases.
The study of the relationship between NUTRITIONAL PHYSIOLOGY and genetic makeup. It includes the effect of different food components on GENE EXPRESSION and how variations in GENES effect responses to food components.
Sequential operating programs and data which instruct the functioning of a digital computer.
Geographic variety, population, or race, within a species, that is genetically adapted to a particular habitat. An ecotype typically exhibits phenotypic differences but is capable of interbreeding with other ecotypes.
The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
The common chimpanzee, a species of the genus Pan, family HOMINIDAE. It lives in Africa, primarily in the tropical rainforests. There are a number of recognized subspecies.
Group of fish under the superorder Acanthopterygii, separate from the PERCIFORMES, which includes swamp eels, mullets, sticklebacks, seahorses, spiny eels, rainbowfishes, and KILLIFISHES. The name is derived from the six taxa which comprise the group. (From, 8/4/2000)
Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.
A plant genus of the family CISTACEAE. The common name of rock rose is also sometimes used with the closely related Helianthemum genus (CISTACEAE).
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.
Coloration or discoloration of a part by a pigment.
The transmission of traits encoded in GENES from parent to offspring.
The presence of apparently similar characters for which the genetic evidence indicates that different genes or different genetic mechanisms are involved in different pedigrees. In clinical settings genetic heterogeneity refers to the presence of a variety of genetic defects which cause the same disease, often due to mutations at different loci on the same gene, a finding common to many human diseases including ALZHEIMER DISEASE; CYSTIC FIBROSIS; LIPOPROTEIN LIPASE DEFICIENCY, FAMILIAL; and POLYCYSTIC KIDNEY DISEASES. (Rieger, et al., Glossary of Genetics: Classical and Molecular, 5th ed; Segen, Dictionary of Modern Medicine, 1992)
Persons living in the United States having origins in any of the black groups of Africa.
A plant genus of the family FABACEAE. Members of this genus can cause CONTACT DERMATITIS.
The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.
A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
A plant genus of the family FAGACEAE that is a source of TANNINS. Do not confuse with Holly (ILEX).
A subdiscipline of human genetics which entails the reliable prediction of certain human disorders as a function of the lineage and/or genetic makeup of an individual or of any two parents or potential parents.
The largest of the continents. It was known to the Romans more specifically as what we know today as Asia Minor. The name comes from at least two possible sources: from the Assyrian asu (to rise) or from the Sanskrit usa (dawn), both with reference to its being the land of the rising sun, i.e., eastern as opposed to Europe, to the west. (From Webster's New Geographical Dictionary, 1988, p82 & Room, Brewer's Dictionary of Names, 1992, p34)
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Diseases that are caused by genetic mutations present during embryo or fetal development, although they may be observed later in life. The mutations may be inherited from a parent's genome or they may be acquired in utero.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
The normal length of time of an organism's life.
The number of mutations that occur in a specific sequence, GENE, or GENOME over a specified period of time such as years, CELL DIVISIONS, or generations.
Groups of individuals whose putative ancestry is from native continental populations based on similarities in physical appearance.
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
The intergenic DNA segments that are between the ribosomal RNA genes (internal transcribed spacers) and between the tandemly repeated units of rDNA (external transcribed spacers and nontranscribed spacers).
Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
Animals considered to be wild or feral or not adapted for domestic use. It does not include wild animals in zoos for which ANIMALS, ZOO is available.
INSECTS of the order Coleoptera, containing over 350,000 species in 150 families. They possess hard bodies and their mouthparts are adapted for chewing.
A coordinated effort of researchers to map (CHROMOSOME MAPPING) and sequence (SEQUENCE ANALYSIS, DNA) the human GENOME.
The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.
A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.
A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)
The total genetic information possessed by the reproductive members of a POPULATION of sexually reproducing organisms.
That part of the genome that corresponds to the complete complement of EXONS of an organism or cell.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The genetic complement of an insect (INSECTS) as represented in its DNA.
The region of DNA which borders the 5' end of a transcription unit and where a variety of regulatory sequences are located.
Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.
Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.

Hidden genetic variability within electromorphs in finite populations. (1/30484)

The amount of hidden genetic variability within electromorphs in finite populations is studied by using the infinite site model and stepwise mutation model simultaneously. A formula is developed for the bivariate probability generating function for the number of codon differences and the number of electromorph state differences between two randomly chosen cistrons. Using this formula, the distribution as well as the mean and variance of the number of codon differences between two identical or nonidentical electromorphs are studied. The distribution of the number of codon differences between two randomly chosen identical electromorphs is similar to the geometric distribution but more leptokurtic. Studies are also made on the number of codon differences between two electromorphs chosen at random one from each of two populations which have been separated for an arbitrary number of generations. It is shown that the amount of hidden genetic variability is very large if the product of effective population size and mutation rate is large.  (+info)

The Lewontin and Krakauer test on quantitative characters. (2/30484)

It is shown that LEWONTIN and KRAKAUER's test could also be applied to quantitative characters that do not show important dominance and epistatic genetic variances. The design of experiments for this purpose and the error of the estimation of F are discussed.  (+info)

Expression of the naturally occurring truncated trkB neurotrophin receptor induces outgrowth of filopodia and processes in neuroblastoma cells. (3/30484)

We have investigated the effects of the truncated trkB receptor isoform T1 (trkB.T1) by transient transfection into mouse N2a neuroblastoma cells. We observed that expression of trkB.T1 leads to a striking change in cell morphology characterized by outgrowth of filopodia and processes. A similar morphological response was also observed in SH-SY5Y human neuroblastoma cells and NIH3T3 fibroblasts transfected with trkB.T1. N2a cells lack endogenous expression of trkB isoforms, but express barely detectable amounts of its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4). The morphological change was ligand-independent, since addition of exogenous BDNF or NT-4 or blockade of endogenous trkB ligands did not influence this response. Filopodia and process outgrowth was significantly suppressed when full-length trkB.TK+ was cotransfected together with trkB.T1 and this inhibitory effect was blocked by tyrosine kinase inhibitor K252a. Transfection of trkB.T1 deletion mutants showed that the morphological response is dependent on the extracellular, but not the intracellular domain of the receptor. Our results suggest a novel ligand-independent role for truncated trkB in the regulation of cellular morphology.  (+info)

Over-representation of a germline RET sequence variant in patients with sporadic medullary thyroid carcinoma and somatic RET codon 918 mutation. (4/30484)

The aetiology of sporadic medullary thyroid carcinoma is unknown. About 50% harbour a somatic mutation at codon 918 of RET (M918T). To investigate whether other RET sequence variants may be associated with or predispose to the development of sporadic medullary thyroid carcinoma, we analysed genomic DNA from the germline and corresponding tumour from 50 patients to identify RET sequence variants. In one patient, tumour DNA showed a novel somatic 12 bp in-frame deletion in exon 15. More interestingly, we found that the rare polymorphism at codon 836 (c.2439C > T; S836S) occurred at a significantly higher frequency than that in control individuals without sporadic medullary thyroid carcinoma (Fisher's exact test, P = 0.03). Further, among the nine evaluable cases with germline c.2439C/T, eight also had the somatic M918T mutation in MTC DNA which was more frequent than in patients with the more common c.2439C/C (89% vs 40%, respectively; Fisher's exact test, P = 0.01). These findings suggest that the rare sequence variant at codon 836 may somehow play a role in the genesis of sporadic medullary thyroid carcinoma.  (+info)

The nuclear receptor superfamily has undergone extensive proliferation and diversification in nematodes. (5/30484)

The nuclear receptor (NR) superfamily is the most abundant class of transcriptional regulators encoded in the Caenorhabditis elegans genome, with >200 predicted genes revealed by the screens and analysis of genomic sequence reported here. This is the largest number of NR genes yet described from a single species, although our analysis of available genomic sequence from the related nematode Caenorhabditis briggsae indicates that it also has a large number. Existing data demonstrate expression for 25% of the C. elegans NR sequences. Sequence conservation and statistical arguments suggest that the majority represent functional genes. An analysis of these genes based on the DNA-binding domain motif revealed that several NR classes conserved in both vertebrates and insects are also represented among the nematode genes, consistent with the existence of ancient NR classes shared among most, and perhaps all, metazoans. Most of the nematode NR sequences, however, are distinct from those currently known in other phyla, and reveal a previously unobserved diversity within the NR superfamily. In C. elegans, extensive proliferation and diversification of NR sequences have occurred on chromosome V, accounting for > 50% of the predicted NR genes.  (+info)

Hemoglobin Providence. A human hemoglobin variant occurring in two forms in vivo. (6/30484)

Hemoglobin Providence Asn and Hemoglobin Providence Asp are two abnormal hemoglobins which apparently arise from a single genetic change that substitutes asparagine for lysine at position 82 (EF6) in the beta chain of human hemoglobin. The second form appears to be thr result of a partial in vivo deamidation of the asparagine situated at position beta 82. Cellulose acetate and citrate agar electrophoresis of hemolysates from patients with this abnormality shows three bands. Globin chain electrophoresis at acid and alkaline pH shows three beta chains. These three chains correspond to the normal beta A chain and two abnormal beta chains. Sequence analysis indicates that the two abnormal chains differ from beta A at only position beta 82. In the two abnormal chains, the residue which is normally lysine is substituted either by asparagine or by aspartic acid. These substitutions are notable because beta 82 lysine is one of the residues involved in 2,3-diphosphoglycerate binding. Additionally, beta 82 lysine is typically invariant in hemoglobin beta chain sequences. Sequence data on the two forms of Hemoglobin Providence are given in this paper. The functional properties of these two forms are described in the next paper.  (+info)

Isolation and characterization of two mouse L cell lines resistant to the toxic lectin ricin. (7/30484)

Two variant mouse L cell lines (termed CL 3 and CL 6) have been selected for resistant to ricin, a galactose-binding lectin with potent cytotoxic activity. The resistant lines exhibit a 50 to 70% decrease in ricin binding and a 300- to 500-fold increase in resistance to the toxic effects of ricin. Crude membrane preparations of CL 3 cells have increased sialic acid content (200% of control), while the galactose, mannose, and hexosamine content is within normal limits. Both the glycoproteins and glycolipids of CL 3 cells have increased sialic acid, with the GM3:lactosylceramide ratios for parent L and CL 3 cells being 0.29 and 1.5, respectively. In contrast, the membranes of CL 6 cells have a decrease in sialic acid, galactose, and hexosamine content with mannose being normal. Both cell lines have specific alterations in glycosyltransferase activities which can account for the observed membrane sugar changes. CL 3 cells have increased CMP-sialic acid:glycoprotein sialyltransferase and GM3 synthetase activities, while CL 6 cells have decrease UDP-GlcNAc:glycoproteinN-acetylglucosaminyltransferase and DPU-galactose:glycoprotein galactosyltransferase activities. The increased sialic acid content of CL 3 cells serves to mask ricin binding sites, since neuraminidase treatment of this cell line restores ricin binding to essentially normal levels. However, the fact that neuraminidase-treated CL 3 cells are still 45-fold resistant to ricin indicates that either a special class of productive ricin binding sites is not being exposed or that the cell line has a second mechanism for ricin resistance.  (+info)

Constitutional genetic variation at the human aromatase gene (Cyp19) and breast cancer risk. (8/30484)

The activity of the aromatase enzyme, which converts androgens into oestrogens and has a major role in regulating oestrogen levels in the breast, is thought to be a contributing factor in the development of breast cancer. We undertook this study to assess the role of constitutional genetic variation in the human aromatase gene (Cyp19) in the development of this disease. Our genotyping of 348 cases with breast cancer and 145 controls (all Caucasian women) for a published tetranucleotide repeat polymorphism at intron 4 of the Cyp19 gene revealed the presence of six common and two rare alleles. Contingency table analysis revealed a significant difference in allelic distribution between cases and controls (chi2 5df = 13.52, P = 0.019). The allele measuring 171 bp was over-represented in cases; of 14 individuals homozygous for this allele, 13 were cases. These individuals had a higher incidence of cancer in family members and an earlier age at diagnosis than other cases. In sequencing Cyp19's coding exons and regulatory regions, we discovered a perfect association between a silent polymorphism (G-->A at Val80) and the high-risk genotype. Our conclusion is that constitutional genetic variation at the Cyp19 locus is associated with the risk of developing breast cancer, with the 171-bp allele serving as the high-risk allele.  (+info)

TY - JOUR. T1 - The nature of quantitative genetic variation in drosophila. II* average dominance of abdominal bristle polygenes. AU - Frankham, R.. PY - 1974. Y1 - 1974. N2 - A comparison of 13 abdominal bristle selection lines with their base population and with reciprocal Fls between the selection lines and the base population was carried out. There was no significant directional contribution of maternally inherited factors to selection response.Different estimates of average dominance ranged from 0·28 to 0·43 with a mean of 0·39. This indicates that the alleles increasing abdominal bristle number are, on average, partly recessive. Some of the possible consequences of this are discussed.. AB - A comparison of 13 abdominal bristle selection lines with their base population and with reciprocal Fls between the selection lines and the base population was carried out. There was no significant directional contribution of maternally inherited factors to selection response.Different estimates of ...
Phylogenetic studies, particularly those based on rDNA sequences from plant roots and basidiomata, have revealed a strikingly high genetic diversity in the Sebacinales. However, the factors determining this genetic diversity at higher and lower taxonomic levels within this order are still unknown. In this study, we analysed patterns of genetic variation within two morphological species, Sebacina epigaea and S. incrustans, based on 340 DNA haplotype sequences of independent genetic markers from the nuclear (ITS + 5.8S + D1/D2, RPB2) and mitochondrial (ATP6) genomes for 98 population samples. By characterising the genetic population structure within these species, we provide insights into species boundaries and the possible factors responsible for genetic diversity at a regional geographic scale. We found that recombination events are relatively common between natural populations within Sebacina epigaea and S. incrustans, and play a significant role in generating intraspecific genetic diversity.
View Notes - Ch 3 - Nature Nurture & Human Diversity from PSYC 101 at UBC. Nature, Nurture & Nature, Human Diversity 100 Oct 6 08 True or False 1) Even complex human traits are determined by a
Cryptic genetic variation (CGV) is the hidden genetic variation that can be unlocked by perturbing normal conditions. CGV can drive the emergence of novel complex phenotypes through changes in gene expression. Although our theoretical understanding of CGV has thoroughly increased over the past decade, insight into polymorphic gene expression regulation underlying CGV is scarce. Here we investigated the transcriptional architecture of CGV in response to rapid temperature changes in the nematode Caenorhabditis elegans. We analyzed regulatory variation in gene expression (and mapped eQTL) across the course of a heat stress and recovery response in a recombinant inbred population. We measured gene expression over three temperature treatments: i) control, ii) heat stress, and iii) recovery from heat stress. Compared to control, exposure to heat stress affected the transcription of 3305 genes, whereas 942 were affected in recovering animals. These affected genes were mainly involved in metabolism and
Different variations in the same gene influence how well different ethnic groups, and people within the same ethnic group, respond to various antipsychotic medications, report NIMH-funded researchers. If confirmed, their findings could one day help clinicians predict which medication is most likely to help a patient, based on his or her genetic makeup.. A medication that works well for one person with schizophrenia often doesnt work well for another. Genetic variations are thought to play a key role in this difference in response. While patients search for the right medications, their illnesses may worsen. Studies such as this one are aimed at discovering how specific gene variations affect patients responses to specific medications, to better match patients to treatments.. The gene containing the variations, RGS4, had been implicated in schizophrenia in previous studies. It makes a protein that is thought to regulate the effects of receptors found on brain cells. The receptors, called ...
Human genetic variation may directly or indirectly influence response to modern antiretroviral therapies for HIV. It is already known that some immunogenetic and other human genetic variations affect the natural history of HIV disease progression where individuals are untreated, but less information is available as to whether these differences are still relevant in the context of HAART. Antiretroviral therapy adds additional opportunities for human genetic contributions to affect variable prognosis--in particular for those genes which influence pharmacokinetics and/or adverse events.
Nucleotide diversity provides a measure of genetic variation that is normalized by the number of chromosomes sampled. We calculated two conventional measures of nucleotide diversity for each gene: π, the average heterozygosity per site (28, 29), and θ, the population mutation parameter (13, 30). The average nucleotide diversity for the 292 autosomal genes (π = 0.058% and θ = 0.096%) and the 21 X-linked genes (π = 0.028% and θ = 0.045%) were within the range of values previously described (2-4). The fact that the average nucleotide diversity for the X-linked genes was reduced compared with the average autosomal nucleotide diversity is consistent with an equal number of males and females in the human population, in which males have only a single copy of the X chromosome.. We also calculated the autosomal nucleotide diversity values separately for each functional gene region and for each population. Exon-intron boundaries showed significantly higher average π values (P , 0.01 by ...
Human genetic variation is expected to play a central role in personalized medicine. Yet only a fraction of the natural genetic variation that is harbored by humans has been discovered to date. Here we report almost 2 million small insertions and deletions (INDELs) that range from 1 bp to 10,000 bp …
Author Summary Like many primate species, the mating system of humans is considered to be moderately polygynous (i.e., males exhibit a higher variance in reproductive success than females). As a consequence, males are expected to have a lower effective population size (Ne) than females, and the proportion of neutral genetic variation on the X chromosome (relative to the autosomes) should be higher than expected under the assumption of strict neutrality and an equal breeding sex ratio. We test for the effects of polygyny by measuring levels of neutral polymorphism at 40 independent loci on the X chromosome and autosomes in six human populations. To correct for mutation rate heterogeneity among loci, we divide our diversity estimates within human populations by divergence with orangutan at each locus. Consistent with expectations under a model of polygyny, we find elevated levels of X-linked versus autosomal diversity. While it is possible that multiple demographic processes may contribute to the observed
The origin and evolution of ORFans (suspected genes without known relatives) remain unclear. Here, we take advantage of a unique opportunity to examine the population diversity of thousands of ORFans, based on a collection of 35 complete genomes of isolates of Escherichia coli and Shigella (which is included phylogenetically within E. coli). As expected from previous studies, ORFans are shorter and AT-richer in sequence than non-ORFans. We find that ORFans often are very narrowly distributed: the most common pattern is for an ORFan to be found in only one genome. We compared within-species population diversity of ORFan genes with those of two control groups of non-ORFan genes. Patterns of population variation suggest that most ORFans are not artifacts, but encode real genes whose protein-coding capacity is conserved, reflecting selection against nonsynonymous mutations. Nevertheless, nonsynonymous nucleotide diversity is higher than for non-ORFans, whereas synonymous diversity is roughly the ...
Background: A molecular process based genotype-to-phenotype map will ultimately enable us to predict how genetic variation among individuals results in phenotypic alterations. Building such a map is, however, far from straightforward. It requires understanding how molecular variation reshapes developmental and metabolic networks, and how the functional state of these networks modifies phenotypes in genotype specific way. We focus on the latter problem by describing genetic variation in transcript levels of genes in the InR/TOR pathway among 72 Drosophila melanogaster genotypes. Results: We observe tight co-variance in transcript levels of genes not known to influence each other through direct transcriptional control. We summarize transcriptome variation with factor analyses, and observe strong co-variance of gene expression within the dFOXO-branch and within the TOR-branch of the pathway. Finally, we investigate whether major axes of transcriptome variation shape phenotypes expected to be influenced
Wright himself believed that values ,0.25 represent very great genetic variation and that an FST of 0.15-0.25 represented great variation. However, about 5% of human variation occurs between populations within continents, therefore FST values between continental groups of humans (or races) of as low as 0.1 (or possibly lower) have been found in some studies, suggesting more moderate levels of genetic variation.[56] Graves (1996) has countered that FST should not be used as a marker of subspecies status, as the statistic is used to measure the degree of differentiation between populations,[56] although see also Wright (1978).[59]. Jeffrey Long and Rick Kittles give a long critique of the application of FST to human populations in their 2003 paper Human Genetic Diversity and the Nonexistence of Biological Races. They find that the figure of 85% is misleading because it implies that all human populations contain on average 85% of all genetic diversity. They argue the underlying statistical model ...
Genetic diversity provides the capacity for plants to meet changing environments. It is fundamentally important in crop improvement. Fifty-nine local maize lines developed at INERA and 41 exotic (temperate and tropical) inbred lines were characterized using 1057 SNP markers to (1) analyse the genetic diversity in a diverse set of maize inbred lines; (2) determine the level of genetic diversity in INERA inbred lines and patterns of relationships of these inbred lines developed from two sources; and (3) examine the genetic differences between local and exotic germplasms. Rogers genetic distance for about 64% of the pairs of lines fell between 0.300 and 0.400. Sixty one per cent of the pairs of lines also showed relative kinship values of zero. Model-based population structure analysis and principal component analysis revealed the presence of 5 groups that agree, to some extent, with the origin of the germplasm. There was genetic diversity among INERA inbred lines, which were genetically less closely
Past events like fluctuations in population size and post-glacial colonization processes may influence the relative importance of genetic drift, migration and selection when determining the present day patterns of genetic variation. We disentangle how drift, selection and migration shape neutral and adaptive genetic variation in 12 moor frog populations along a 1700 km latitudinal gradient. We studied genetic differentiation and variation at a MHC exon II locus and a set of 18 microsatellites. Using outlier analyses, we identified the MHC II exon 2 (corresponding to the β-2 domain) locus and one microsatellite locus (RCO8640) to be subject to diversifying selection, while five microsatellite loci showed signals of stabilizing selection among populations. STRUCTURE and DAPC analyses on the neutral microsatellites assigned populations to a northern and a southern cluster, reflecting two different post-glacial colonization routes found in previous studies. Genetic variation overall was lower in the
View Notes - 640Lecture0705 from EEOB 640 at Ohio State. TYPES OF GENETIC VARIATION protein variation how do we measure variability structural similarity? how immunology Variation in enzyme
Selection against deleterious alleles maintained by mutation may cause a reduction in the amount of genetic variability at linked neutral sites. This is because a new neutral variant can only remain in a large population for a long period of time if it is maintained in gametes that are free of deleterious alleles, and hence are not destined for rapid elimination from the population by selection. Approximate formulas are derived for the reduction below classical neutral values resulting from such background selection against deleterious mutations, for the mean times to fixation and loss of new mutations, nucleotide site diversity, and number of segregating sites. These formulas apply to random-mating populations with no genetic recombination, and to populations reproducing exclusively asexually or by self-fertilization. For a given selection regime and mating system, the reduction is an exponential function of the total mutation rate to deleterious mutations for the section of the genome ...
TY - JOUR. T1 - PCSK9 Loss-of-Function Variants, Low-Density Lipoprotein Cholesterol, and Risk of Coronary Heart Disease and Stroke. T2 - Data from 9 Studies of Blacks and Whites. AU - Kent, Shia T.. AU - Rosenson, Robert S.. AU - Avery, Christy L.. AU - Chen, Yii Der I.. AU - Correa, Adolfo. AU - Cummings, Steven R.. AU - Cupples, L. Adrienne. AU - Cushman, Mary. AU - Evans, Daniel S.. AU - Gudnason, Vilmundur. AU - Harris, Tamara B.. AU - Howard, George. AU - Irvin, Marguerite R.. AU - Judd, Suzanne E.. AU - Jukema, J. Wouter. AU - Lange, Leslie. AU - Levitan, Emily B.. AU - Li, Xiaohui. AU - Liu, Yongmei. AU - Post, Wendy S.. AU - Postmus, Iris. AU - Psaty, Bruce M.. AU - Rotter, Jerome I.. AU - Safford, Monika M.. AU - Sitlani, Colleen M.. AU - Smith, Albert V.. AU - Stewart, James D.. AU - Trompet, Stella. AU - Sun, Fangui. AU - Vasan, Ramachandran S.. AU - Woolley, J. Michael. AU - Whitsel, Eric A.. AU - Wiggins, Kerri L.. AU - Wilson, James G.. AU - Muntner, Paul. PY - 2017/8/1. Y1 - ...
TY - JOUR. T1 - A systematic survey of loss-of-function variants in human protein-coding genes. AU - MacArthur, Daniel G.. AU - Balasubramanian, Suganthi. AU - Frankish, Adam. AU - Huang, Ni. AU - Morris, James. AU - Walter, Klaudia. AU - Jostins, Luke. AU - Habegger, Lukas. AU - Pickrell, Joseph K.. AU - Montgomery, Stephen B.. AU - Albers, Cornelis A.. AU - Zhang, Zhengdong. AU - Conrad, Donald F.. AU - Lunter, Gerton. AU - Zheng, Hancheng. AU - Ayub, Qasim. AU - DePristo, Mark A.. AU - Banks, Eric. AU - Hu, Min. AU - Handsaker, Robert E.. AU - Rosenfeld, Jeffrey A.. AU - Fromer, Menachem. AU - Jin, Mike. AU - Mu, Xinmeng Jasmine. AU - Khurana, Ekta. AU - Ye, Kai. AU - Kay, Mike. AU - Saunders, Gary Ian. AU - Suner, Marie Marthe. AU - Hunt, Toby. AU - Barnes, If H A. AU - Amid, Clara. AU - Carvalho-Silva, Denise R.. AU - Bignell, Alexandra H.. AU - Snow, Catherine. AU - Yngvadottir, Bryndis. AU - Bumpstead, Suzannah. AU - Cooper, David N.. AU - Xue, Yali. AU - Romero, Irene Gallego. AU - Wang, ...
The rare orchid, Isotria medeoloides (Pursh) Raf., is a threatened species native to the Eastern United States. The species range extends from Maine to Georgia, with many populations including fewer than 25 individuals. The degree of genetic variation among populations could have important implications for conservation strategies. This study evaluated the level of genetic variation within and among I. medeoloides populations through analysis of microsatellite regions, which contain dinucleotide repeats. The lengths of these regions are highly variable and have high mutation rates, making microsatellites a powerful genetic marker. Genetic variation was assessed at two microsatellite loci among 15 populations and three regions (New England, Virginia and Georgia). In this largely self-pollinating species, the inbreeding coefficient was high (Fis =0.964) indicating a high rate of self-fertilization. Populations in New England harbor the most genetic diversity. Southern populations are monomorphic, or
A graphical representation of the typical human karyotype. The human mitochondrial DNA.Human genetic variation is the genetic differences in and among populations. There may be multiple variants of a
AFTER the establishment of the field of ecological genetics more than 30 years ago (Clarke 1975) rapid progress in molecular marker development and analysis technology has generated a surge of renewed interest in identification of selective footprints of natural selection in a wide range of species (e.g., Schlötterer 2002). Among numerous research strategies developed to infer the evidence of selection in natural populations at the molecular level (reviewed by Nielsen 2005; Vasemägi and Primmer 2005), associations between environmental variables and molecular marker polymorphisms are commonly taken as strong support for the hypothesis that natural selection maintains single-locus clinal variation (e.g., Eanes 1999; Baines et al. 2004). However, it has often been overlooked that single-locus clines can also be the result of various neutral evolutionary processes, such as hybridization of previously isolated populations, founder events, and migrational patterns, such as spatially restricted gene ...
Estimating KIR Haplotype Frequencies on a Cohort of 10,000 Individuals: A Comprehensive Study on Population Variations, Typing Resolutions, and Reference Haplotypes. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
It is well known that the effective size of a population (Ne) is one of the major determinants of the amount of genetic variation within the population. However, it is unclear whether the types of genetic variations are also dictated by the effective population size. To examine this, we obtained whole genome data from over 100 populations of the world and investigated the patterns of mutational changes. Our results revealed that for low frequency variants, the ratio of AT→GC to GC→AT variants (β) was similar across populations, suggesting the similarity of the pattern of mutation in various populations. However, for high frequency variants, β showed a positive correlation with the effective population size of the populations. This suggests a much higher proportion of high frequency AT→GC variants in large populations (e.g. Africans) compared to those with small population sizes (e.g. Asians). These results imply that the substitution patterns vary significantly between populations. These
Evolutionary developmental genetics has historically been carried out by two teams: Molecular evolutionists who emphasize divergence between species or increased taxa, and quantitative geneticists who examine variation inside species. Neither strategy actually involves grips with the complexities of evolutionary transitions, notably in mild of the conclusion from genome-wide affiliation research that the majority complicated traits match an infinitesimal structure, being influenced by 1000s of loci. This paper discusses robustness, plasticity and lability, phenomena that we argue potentiate main evolutionary adjustments and supply a bridge between the conceptual therapies of macro- and micro-evolution.. We provide cryptic genetic variation and conditional neutrality as mechanisms by which standing genetic variation can result in developmental system drift and, sheltered inside canalized processes, could facilitate developmental transitions and the evolution of novelty. Synthesis of the 2 ...
9780131838765 Our cheapest price for Race and Human Diversity: A Biocultural Approach is $44.89. Free shipping on all orders over $35.00.
Most biological traits of human importance are complex in nature; their manifestation controlled by the cumulative effect of many genetic factors interacting with one another and with the individuals life history. Because of this, mouse genetic reference populations (GRPs) consisting of collections of inbred lines or recombinant inbred lines (RIL) derived from crosses between inbred lines are of particular value in analysis of complex traits, since massive amounts of data can be accumulated on the individual lines. However, existing mouse GRPs are derived from inbred lines that share a common history, resulting in limited genetic diversity, and reduced mapping precision due to long-range gametic disequilibrium. To overcome these limitations, the Collaborative Cross (CC) a genetically highly diverse collection of mouse RIL was established. The CC, now in advanced stages of development, will eventually consist of about 500 RIL derived from reciprocal crosses of eight divergent founder strains of mice,
Some people experience more bitterness and less sweetness when drinking alcoholic beverages, and this relates to inherited genes.
KVAR1 : Diagnostic or predictive testing for specific conditions when a DNA sequence variant of interest has been previously identified in a family member, and follow-up testing for this specific variant in other family members is desired   Carrier screening for individuals at risk for having a DNA sequence variant that was previously identified in a family member   Segregation analysis for a single familial DNA sequence variant
NKX3.1 and β-catenin expression variations might be related to macrophage infiltration in tissues consequent to inflammation.Tissues adjacent to the sections w
Scientists use cancer biomarkers to predict a patients risk of developing cancer, their prognosis and response to therapy and their chance of disease recurrence. A biomarker could be a genetic mutation, the presence of a particular protein or an inherited genetic variation. Moffitt researchers focused their attention on inherited genetic variations in genes called interleukins. They genotyped the DNA of 33 interleukin genes from 651 NSCLC patients. Interleukins have important roles in regulating cell growth, cell death and in the activation of the immune system, explained Matthew Schabath, Ph.D., assistant member of the Cancer Epidemiology Program at Moffitt. Inherited genetic variations in interleukins and other genes can change their function and promote cancer development or control a patients response to therapy. The researchers discovered that patients who had certain genetic variations in interleukin genes had a better response to either surgery or chemotherapy, resulting in ...
Alternative splicing of genes is an efficient means of generating variation in protein function. Several disease states have been associated with rare genetic variants that affect splicing patterns. Conversely, splicing efficiency of some genes is known to vary between individuals without apparent ill effects. What is not clear is whether commonly observed phenotypic variation in splicing patterns, and hence potential variation in protein function, is to a significant extent determined by naturally occurring DNA sequence variation and in particular by single nucleotide polymorphisms (SNPs). In this study, we surveyed the splicing patterns of 250 exons in 22 individuals who had been previously genotyped by the International HapMap Project. We identified 70 simple cassette exon alternative splicing events in our experimental system; for six of these, we detected consistent differences in splicing pattern between individuals, with a highly significant association between splice phenotype and neighbouring
Since the extent and distribution of disease predisposing genetic variation in the human species today is the result of a long and complicated evolutionary, migratory, and demographic history, we are interested in investigating population and evolutionary processes affecting genetic variations in modern human populations. We have been working on assessing the extent of inter- and intra-population genomic variation and detecting signatures of positive natural selection as well as investigating genomic variation across multiple global and regional populations. In addition, we are also interested in understanding the history of introgression from archaic sister species and their distribution into extant human populations as well as the convergent evolution between domesticated species (e.g. dogs) and human beings. Such population and evolutionary genomic studies provide a unique opportunity to look at disease genetics at a much broader scale. Furthermore, we are also interested in developing novel ...
TY - JOUR. T1 - Distribution and effects of nonsense polymorphisms in human genes. AU - Yamaguchi-Kabata, Yumi. AU - Shimada, Makoto K.. AU - Hayakawa, Yosuke. AU - Minoshima, Shinsei. AU - Chakraborty, Ranajit. AU - Gojobori, Takashi. AU - Imanishi, Tadashi. PY - 2008/10/14. Y1 - 2008/10/14. N2 - Background: A great amount of data has been accumulated on genetic variations in the human genome, but we still do not know much about how the genetic variations affect gene function. In particular, little is known about the distribution of nonsense polymorphisms in human genes despite their drastic effects on gene products. Methodology/Principal Findings: To detect polymorphisms affecting gene function, we analyzed all publicly available polymorphisms in a database for single nucleotide polymorphisms (dbSNP build 125) located in the exons of 36,712 known and predicted protein-coding genes that were defined in an annotation project of all human genes and transcripts (H-InvDB ver3.8). We found a total ...
The nature of standing genetic variation and its relation to phenotypic variation in plants affects our understanding of evolution (1), sustainable agriculture, and preservation of inter- and intraspecific variation in times of environmental change. Maize inbred lines have an average nucleotide diversity in genic regions around 1% (π = 1 to 1.4%) (2, 3), similar to the divergence between humans and chimpanzees (4). It is not uncommon to find maize haplotypes that are 5% divergent from one another (5), which indicates that the maize gene pool reaches back 2 to 4 million years (with one generation per year).. Maize is adapted to a range of environments from the lowland tropics to the Andean highlands and has been widely introduced worldwide into both temperate and tropical regions. Maizes genetic architecture for flowering time has evolved as its wild relatives adapted to distinct ecological zones in elevations differing by more than 3000 m in Mexico and then under both natural and artificial ...
Photo: Dr. Andrew Olshan]. This is the finding of a new large-scale genetic study of head and neck cancers co-authored by Dr. Andrew Olshan, Barbara Sorenson Hulka Distinguished Professor in cancer epidemiology and chair of the department of epidemiology at the University of North Carolinas Gillings School of Global Public Health. A write-up of the study appears in the October 17 issue of Nature Genetics.. The study, which involved nearly 12,000 people - half with cancer of the oral cavity or pharynx, and half without any such cancer - showed why some individuals infected with HPV may go on to develop oropharyngeal cancer while others do not. The researchers conducted extensive DNA analysis of more than seven million variants for each individual. The UNC site contributed samples from the Carolina Head and Neck Cancer (CHANCE) study, led by Dr. Olshan.. These new findings on the association of immune system-related genetic variation may provide new insight into the mechanisms of protection ...
Habitat fragmentation threatens the maintenance of genetic diversity of affected populations. Assessment of the risks associated with habitat fragmentation is a big challenge as the change in population genetic diversity is a dynamic process, often acting over long time periods and depending on various characteristics pertaining to both species (life history traits) and their populations (extrinsic characteristics). With this survey, we provide an introductory overview for persons who have to make or are interested in making predictions about the fate of forest-dwelling plant populations which have recently become fragmented and isolated from their main occurrences. We provide a concise introduction to the field of population genetics focusing on terms, processes and phenomena relevant to the maintenance of genetic diversity and vitality of plant populations. In particular the antagonistic effects of gene flow and random genetic drift are covered. A special chapter is devoted to Central European tree
Some genetic variations may affect our health by altering how DNA coils and interacts in its 3-D shape - Highlight
Genetic variations may hold clues to rheumatoid arthritis -- suggesting not only who will develop the condition, but also predicting its severity and a patients mortality risk.
These results illustrate the highly dynamic pattern of CGV across three different environmental conditions that can be evoked by a stress response over a relatively short time-span (2 h) and that CGV is mainly determined by response related trans regulatory eQTL.
The identification and characterization of functional genetic variation is essential for future advances in molecular diagnostics, pharmacogenomics, and personalized medicine. Recent attempts at identifying nucleotide level variation (somatic mutations and single nucleotide polymorphisms [SNPs]) on a genomic scale have linked variation to gene expression, however fail to provide mechanisms for how variation can affect protein function. Herein I have identified nucleotide variation that affects the activity of two proto-oncogenes, MYC (c-Myc) and MYB (c-Myb), and characterized the role this variation plays in oncogenesis and cell differentiation. Burkitts Lymphomas (BLs) acquire consistent point mutations in a conserved Myc Box I domain. In Chapter 2, I report that the enhanced transforming activity of BL-associated MYC mutants can be uncoupled from loss of phosphorylation and increased protein stability. Furthermore, two different BL-associated MYC mutations induced similar gene expression ...
Variation is the driving force behind evolution and the reason why any species persists on this planet. Yet the science of human diversity is curtailed by controversial politics and outcries against racism. Some resistance comes from indigenous groups who feel they would be lab rats, but most comes from cautious government groups like the European Union, who at one point banned all research into human diversity. As a result gene studies were forced to obliterate the ethnic source of their samples.. Of course it is important to be sensitive to the threat of racism; historically human diversity science has led to eugenic groups, the sterilisation of undesirables and most infamously, the hideous acts committed by the Nazis. However science is the only real route to defeating ignorance (listening Daily Mail?) and as gene trials have progressed it has become obvious that the main differences are ones we see - hair, skin colour and facial features. We might have just our mothers eyes, but we all ...
Professor Louis Bernatchez - Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec; Canada Research Chair in Genetic Management of Freshwater Species. Species across the globe are experiencing drastic changes in environmental conditions as a result of human activities. Understanding and predicting how organisms respond to human-driven environmental change is therefore a major concern.
According to current research, the African continent is the ancestral home of modern humans. Scientists studying patterns in human genetic variation have observed the greatest amount of human genetic diversity in African populations. Genetic variation outside of Africa-in Europe and Asia-includes some, but not all, of the genetic variation found in Africa, which suggests that between 140,000 and 290,000 years ago, Homo sapiens migrated out of Africa to colonize Europe, Asia and the Americas. This Out of Africa theory is supported by studies of mtDNA, the Y chromosome, portions of the X chromosome, and some but not all autosomal (non-sex determining) regions, as well as the archaeological record. The role of genetics in human variation had to evolve before the Out of Africa theory of ancestry could be fully understood. Perhaps the most significant scientific development in helping to further understand human biological variation was the discovery of genes and the growth of genetic research. In ...
A study carried out by dozens of scientists, and published in Nature Genetics, identified 15 new genetic markers that can increase the risk of breast cancer. Each of these genetic variations, identified through this study and other research, is known to raise a womans risk of breast cancer by a small amount. Its another step towards a better understanding of how genetic variations work to increase the risk of this type of cancer. ...
Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume Genetic improvement programmes: Selection using molecular information - Lecture Sessions, , 0944, ...
The blobs are constructed and arranged so that the average distance between two points (individuals) within the same cluster is almost as big as the average distance between two points (individuals) in different clusters. This is easy to achieve if the ellipsoids are big and flat (like pancakes) and placed close to each other along the flat directions. The figure is meant to show how one can have small Fst, as in humans, yet easily resolved clusters. The direction in which the gap between the clusters appears is one of the principal components in the space of human genetic variation, as recently found by bioinformaticists. The figure at the top of this post plots individuals as points in the space generated by the two largest principal components extracted from the combination of data from HapMap and from large statistics sampling of Europeans. Exhibited this way, isolated clusters (races) are readily apparent ...
TY - JOUR. T1 - Genetic variation and neurological disease. AU - Rosenberg, Roger N.. PY - 1980. Y1 - 1980. N2 - Genetic mutants inevitably affect enzyme structure or modify protein metabolism. In some cases a single genetic defect can give rise to a neurological syndrome, but in most cases the genetic basis of neurological disease is far more complex. In this review Roger Rosenberg examines the rapid progress which is being made in identifying the patterns of genetic variation which underlie these problems, and their effective treatment.. AB - Genetic mutants inevitably affect enzyme structure or modify protein metabolism. In some cases a single genetic defect can give rise to a neurological syndrome, but in most cases the genetic basis of neurological disease is far more complex. In this review Roger Rosenberg examines the rapid progress which is being made in identifying the patterns of genetic variation which underlie these problems, and their effective treatment.. UR - ...
TY - JOUR. T1 - RNA-seq analysis reveals considerable genetic diversity and provides genetic markers saturating all chromosomes in the diploid wild wheat relative Aegilops umbellulata. AU - Okada, Moeko. AU - Yoshida, Kentaro. AU - Nishijima, Ryo. AU - Michikawa, Asami. AU - Motoi, Yuka. AU - Sato, Kazuhiro. AU - Takumi, Shigeo. PY - 2018/11/8. Y1 - 2018/11/8. N2 - Background: Aegilops umbellulata Zhuk. (2n=14), a wild diploid wheat relative, has been the source of trait improvement in wheat breeding. Intraspecific genetic variation of Ae. umbellulata, however, has not been well studied and the genomic information in this species is limited. Results: To develop novel genetic markers distributed over all chromosomes of Ae. umbellulata and to evaluate its genetic diversity, we performed RNA sequencing of 12 representative accessions and reconstructed transcripts by de novo assembly of reads for each accession. A large number of single nucleotide polymorphisms (SNPs) and insertions/deletions ...
Aberrations in chromosomal copy number are one of the most common molecular features observed in cancer. Quantifying the degree of numerical chromosomal variation in single cells across a population of cells is of interest to researchers studying whole chromosomal instability (W-CIN). W-CIN, a state of high numerical chromosomal variation, contributes to treatment resistance in cancer. Here, we introduce aneuvis, a web application that allows users to determine whether numerical chromosomal variation exists between experimental treatment groups. The web interface allows users to upload molecular cytogenetic or processed whole-genome sequencing data in a cell-by-chromosome matrix format and automatically generates visualizations and summary statistics that reflect the degree of numeric chromosomal variability. Aneuvis is the first user-friendly web application to help researchers identify the genetic and environmental perturbations that promote numerical chromosomal variation.
Genetic diversity and population structure analysis between Indian red jungle fowl and domestic chicken using microsatellite markers. ...
Ex situ conservation, while helpful in humankinds efforts to sustain and protect our environment, is rarely enough to save a species from extinction. It is to be used as a last resort, or as a supplement to in situ conservation because it cannot recreate the habitat as a whole: the entire genetic variation of a species, its symbiotic counterparts, or those elements which, over time, might help a species adapt to its changing surroundings. Instead, ex situ conservation removes the species from its natural ecological contexts, preserving it under semi-isolated conditions whereby natural evolution and adaptation processes are either temporarily halted or altered by introducing the specimen to an unnatural habitat. In the case of cryogenic storage methods, the preserved specimens adaptation processes are (quite literally) frozen altogether. The downside to this is that, when re-released, the species may lack the genetic adaptations and mutations which would allow it to thrive in its ever-changing ...
Analysis of the amount and distribution of genetic variation can yield information about the number of introductions and history of an invasive species, which may be relevant for understanding the evolutionary potential and spread of invaders, as well as for creating best management practices for curbing them. We explored the genetic patterns and invasion history of the perennial, ornamental herb Lupinus polyphyllus Lindl. in Finland, where the species has spread rapidly during the past hundred years. Using 13 microsatellite loci, we determined the genetic variation of L. polyphyllus in 51 sites across a latitudinal gradient that reflected the invasion history of the species in this country. We found that the sampled populations were significantly genetically differentiated among sites, as indicated by the global F(ST) value (0.19) and AMOVA results (16.7 % of total genetic variation occurred among sites), and this differentiation slightly increased with increasing geographic distance (r = ...
Rapid development of sequencing technologies and bioinformatic tools makes the complete genome sequencing of many species possible, which provides a starting point to unravel the tremendous genetic variation and diversity at the genome scale. Amongst several model organisms examined to date, such as human, mouse, Arabidopsis, rice, and maize, genome-wide patterns of genetic variation are able to be captured by sampling a relatively small number of genomes [14, 20, 50-52]. By resequencing two sweet and one grain sorghum inbred lines, we uncovered nearly two million SNPs and indels, along with large numbers of PAVs and CNVs. This is a first report on the genome-wide patterns of genetic variation in sorghum, which will be valuable for further genotype-phenotype studies and for molecular breeding of this important C4 model crop.. Our study shows that the proportions of genic SNPs identified as in coding regions, intronic regions, or UTRs are 42.3%, 50.2%, and 7.5%, respectively. Compared to ...
The genetic diversity of Setipinna taty, which is commercially fished in the China Sea, was studied based on mitochondrial DNA control region sequences. PCR was used to amplify the control region fragment in 100 individuals of S. taty collected from Weihai (WH), Yantai (YT), Zhoushan (ZS), Xiangshan (XS), and Ninghai (NH) in China. A control region fragment of 656 bp was successfully sequenced in these 100 individuals. The A+T content of this S. taty control region was 71.7%; 172 variable sites and 62 haplotypes were found.
Population genetic structure and intrapopulation levels of genetic variation have important implications for population dynamics and evolutionary processes. Habitat fragmentation is one of the major threats to biodiversity. It leads to smaller population sizes and reduced gene flow between populations and will thus also affect genetic structure. We use a natural system of island and mainland populations of house sparrows along the coast of Norway to characterize the different population genetic properties of fragmented populations. We genotyped 636 individuals distributed across 14 populations at 15 microsatellite loci. The level of genetic differentiation was estimated using F-statistics and specially designed Mantel tests were conducted to study the influence of population type (i.e. mainland or island) and geographic distance on the genetic population structure. Furthermore, the effects of population type, population size and latitude on the level of genetic variation within populations were ...
The 1000 Genomes Project set out to provide a comprehensive description of common human genetic variation by applying whole-genome sequencing to a diverse set of individuals from multiple populations. Here we report completion of the project, having reconstructed the genomes of 2,504 individuals from 26 populations using a combination of low-coverage whole-genome sequencing, deep exome sequencing, and dense microarray genotyping. We characterized a broad spectrum of genetic variation, in total over 88 million variants (84.7 million single nucleotide polymorphisms (SNPs), 3.6 million short insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes. This resource includes ,99% of SNP variants with a frequency of ,1% for a variety of ancestries. We describe the distribution of genetic variation across the global sample, and discuss the implications for common disease studies ...
Background: Population differentiation has proved to be effective for identifying loci under geographically-localized positive selection, and has the potential to identify loci subject to balancing selection. We have previously investigated the pattern of genetic differentiation among human populations at 36.8 million genomic variants to identify sites in the genome showing high frequency differences. Here, we extend this dataset to include additional variants, survey sites with low levels of differentiation, and evaluate the extent to which highly differentiated sites are likely to result from selective or other processes. Results: We demonstrate that while sites of low differentiation represent sampling effects rather than balancing selection, sites showing extremely high population differentiation are enriched for positive selection events and that one half may be the result of classic selective sweeps. Among these, we rediscover known examples, where we actually identify the established ...
In most existing genetic variant association studies, common trait, common variants, which asserts that common genetic variants contribute to most of traits (disease susceptibilities), serves as the central assumption. Researchers have successfully identified some significant associations between common single nucleotide polymorphisms (SNPs) and disease traits [1]. However, despite the enormous efforts expended on association studies of complex traits, common genetic variants only show a moderate influence on different phenotypes in many reported disease associations and consequently have limited diagnostic value [2, 3]. While the identification of common variants creates a dilemma, known as common trait, rare variants, an alternative hypothesis, which asserts that multiple rare variants with moderate to high penetrances may collectively influence disease susceptibilities, has been suggested in some literatures [3-5]. Rare variants are defined as those whose minor allele frequencies (MAF) ...
TY - JOUR. T1 - Neandertal origin of genetic variation at the cluster of OAS immunity genes. AU - Mendez, Fernando L.. AU - Watkins, Joseph C.. AU - Hammer, Michael F.. PY - 2013/4/1. Y1 - 2013/4/1. N2 - Analyses of ancient DNA from extinct humans reveal signals of at least two independent hybridization events in the history of non-African populations. To date, there are very few examples of specific genetic variants that have been rigorously identified as introgressive. Here, we survey DNA sequence variation in the OAS gene cluster on chromosome 12 and provide strong evidence that a haplotype extending for ∼185 kb introgressed from Neandertals. This haplotype is nearly restricted to Eurasians and is estimated to have diverged from the Neandertal sequence ∼125 kya. Despite the potential for novel functional variation, the observed frequency of this haplotype is consistent with neutral introgression. This is the second locus in the human genome, after STAT2, carrying distinct haplotypes that ...
An international team of more than 1,000 scientists participated in a new study showing an integrated map of genetic variation from 1,092 human genomes.. A newly published compendium of the genetic alphabets of more than 1000 individuals from around the world illustrates how similar humans are - but also how crucial genetic variations can be.. The publication on November 1 in the journal Nature of the 1000 Genomes Project provides the most comprehensive catalog of human variations to date and will be indispensable to the practice of personalized medicine.. Sequencing an individuals DNA is useless in medicine unless there is a frame of reference to compare it to, said Yale Universitys Mark Gerstein, the Albert L. Williams Professor of Biomedical Informatics and one of more than 1,000 scientists who participated in international effort.. An individual human genome contains on an average 3 million variations. Without a reference library of variations, trying to hone in on the most informative ...
...Two genes in which variation affects intake of caffeine the most wide...The genes identified were CYP1A2 which has previously been implicated...Caffeine is implicated in numerous physiological and medical condition...Apart from smoking genetic determinants of lifestyle behaviors have g...,Genetic,variants,associated,with,caffeine,intake,identified,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters
Genetic diversity within species may promote resilience to environmental change, yet little is known about how such variation is distributed at broad geographic scales. Here we develop a novel Bayesian methodology to analyse multi-species genetic diversity data in order to identify regions of high or low genetic diversity. We apply this method to co-distributed taxa from Australian marine waters. We extracted published summary statistics of population genetic diversity from 118 studies of 101 species and | 1000 populations from the Australian marine economic zone. We analysed these data using two approaches: a linear mixed model for standardised data, and a mixed beta-regression for unstandardised data, within a Bayesian framework. Our beta-regression approach performed better than models using standardised data, based on posterior predictive tests. The best model included region (Integrated Marine and Coastal Regionalisation of Australia (IMCRA) bioregions), latitude and latitude squared. Removing
TY - JOUR. T1 - POT1 loss-of-function variants predispose to familial melanoma. AU - Robles-Espinoza, Carla Daniela. AU - Harland, Mark. AU - Ramsay, Andrew J.. AU - Aoude, Lauren G.. AU - Quesada, Victor. AU - Ding, Zhihao. AU - Pooley, Karen A.. AU - Pritchard, Antonia L.. AU - Tiffen, Jessamy C.. AU - Petljak, Mia. AU - Palmer, Jane M.. AU - Symmons, Judith. AU - Johansson, Peter A.. AU - Stark, Mitchell S.. AU - Gartside, Michael G.. AU - Snowden, Helen. AU - Montgomery, Grant W.. AU - Martin, Nicholas G.. AU - Lite, Jimmy Z.. AU - Choi, Jiyeon. AU - Makowski, Matthew. AU - Brown, Kevin M.. AU - Dunning, Alison M.. AU - Keane, Thomas M.. AU - Lopez-Otin, Carlos. AU - Gruis, Nelleke A.. AU - Hayward, Nicholas K.. AU - Bishop, D. Timothy. AU - Newton-Bishop, Julia A.. AU - Adams, David J.. N1 - © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.. PY - 2014/5. Y1 - 2014/5. N2 - Deleterious germline variants in CDKN2A account for around 40% of familial melanoma ...
The historical demography of the populations of domestic pigs in Europe and China was examined using mismatch distributions, which represent the frequency distribution of pairwise differences among all sampled haplotypes. Theoretical studies have shown that population bottlenecks and population expansions have a strong effect on the pattern of genetic polymorphism among haplotypes in the population (Rogers & Harpending 1992). For instance, populations in long and stable demographic equilibrium have multimodal mismatch distribution (ragged and chaotic) whereas the distribution appears unimodal after recent demographic expansions (Rogers & Harpending 1992; Harpending 1994). The mismatch distributions as well as the network analysis were consistent with population expansions in the ancestors for both contemporary Chinese and European domestic pigs (figures 3 and 4). The crucial question is whether the population expansion occurred before or after domestication. Similar signatures of population ...
Brewer, N., DeFrank, J., Chiu, W., Ibrahim, J., Walko, C., Rubin, P., ... Irvin, W. (2014). Patient understanding of how genotype variation affects benefits of tamoxifen therapy for breast cancer. Public Health Genomics, 17(1), 43 - 47 ...
BackgroundSesame is an important oil crop widely cultivated in Africa and Asia continent. Characterization of genetic diversity and population structure of sesame genotypes in these continents can be used to designing breeding methods. In the present study, 300 sesame g...
The Society runs two themed meetings each year as satellites to either the American or European Societies of Human Genetics annual meeting as a forum for scientists to exchange ideas and form collaborations. Prominent speakers in the field are invited. The meetings are designed to update and increase knowledge of human genome variation and generally attract a stimulating and interesting collection of abstracts in all fields of human genome variation making it an ideal forum to share information and results. We invite members and non-members alike to attend these meetings.. FORTHCOMING HGVS MEETINGS ...
Comparing different methods of estimating the genetic diversity could define their usefulness in plant breeding programs. In this study, a total of 18 morphological traits and 20 simple sequence repeat (SSR) loci were used to study the morphological and genetic diversity among 20 maize hybrids selected from different countries, and to classify the hybrids into groups based on molecular profiles and morphological traits. To collect morphological data, a field experiment was carried out using an RBCD design with three replications in Moghan, Ardabil, Iran. The highest estimates for genetic coefficients of variation were observed in anthesis-silking interval, followed by grain yields, leaf chlorophyll rates, kernel row numbers, and ear heights. The total number of PCR-amplified products was 84 bands, all of which were polymorphic. Among the studied primers,NC009,BNLG1108,BNLG1194,PHI026 and PHI057 showed the maximum polymorphism information content(PIC) and the greatest diversity. To determine the genetic
TY - JOUR. T1 - Lipid and sterol gene sequence variation in autism and correlates with neurodevelopmental status. T2 - A pilot study. AU - Hall, Trevor A.. AU - Steiner, Robert D.. AU - Wright, Hollis. AU - Wilmot, Beth. AU - Roullet, Jean Baptiste. AU - Peters, Meaghan. AU - Harris, Michael. N1 - Funding Information: Research reported in this publication was also supported by National Center for Advancing Translational Sciences of the National Institutes of Health under award number UL1TR000128 . The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Funding Information: Research reported in this publication was supported by the Northwest Health Foundation under the Mark O. Hatfield Research Fellowship on Autism. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Northwest Health Foundation. PY - 2015/9/1. Y1 - 2015/9/1. N2 - Objective: ...
There were more than one thousand soybean(Glycine max(L.) Merr)germplasms in Hubei province.In order to evaluate the genetic diversity of summer sowing soybean landraces from different agricultural divisions of Hubei,we analyzed allelic profiles at 28 simple-sequence repeat(SSR) loci of 92 accessions.The SSR loci produced 134 alleles,and each SSR loci could detect 2 to 9 alleles with an average of 4.78 alleles per loci.The highest averages of both genetic diversity index and alleles were all occurred in southwest division,and second one was Jianghan Plain division.More than 83.6% of total variation was produced by geographical differentiation.By using the cluster analysis with Within-groups Linkage method,92 landraces were classified into three major groups at DNA level.Many landraces from southwest division and Jianghan Plain were clustered in Ⅰand Ⅲ group respectively.It was suggested that the diversity level of soybean landrace from both southwest and Jianghan Plain division were higher than
Understanding genome to phenotype linkages has been greatly enabled by genomic sequencing. However, most genome analysis is typically confined to the nuclear genome. We conducted a metabolomic QTL analysis on a reciprocal RIL population structured to examine how variation in the organelle genomes affects phenotypic variation. This showed that the cytoplasmic variation had effects similar to, if not larger than, the largest individual nuclear locus. Inclusion of cytoplasmic variation into the genetic model greatly increased the explained phenotypic variation. Cytoplasmic genetic variation was a central hub in the epistatic network controlling the plant metabolome. This epistatic influence manifested such that the cytoplasmic background could alter or hide pairwise epistasis between nuclear loci. Thus, cytoplasmic genetic variation plays a central role in controlling natural variation in metabolomic networks. This suggests that cytoplasmic genomes must be included in any future analysis of natural ...
Soybean (Glycine max) cultivars adapted to high latitudes have a weakened or absent sensitivity to photoperiod. The purposes of this study were to determine the molecular basis for photoperiod insensitivity in various soybean accessions, focusing on the sequence diversity of the E4 (GmphyA2) gene, which encodes a phytochrome A (phyA) protein, and its homoeolog (GmphyA1), and to disclose the evolutionary consequences of two phyA homoeologs after gene duplication. We detected four new single-base deletions in the exons of E4, all of which result in prematurely truncated proteins. A survey of 191 cultivated accessions sourced from various regions of East Asia with allele-specific molecular markers reliably determined that the accessions with dysfunctional alleles were limited to small geographical regions, suggesting the alleles recent and independent origins from functional E4 alleles. Comparison of nucleotide diversity values revealed lower nucleotide diversity at non-synonymous sites in GmphyA1 than in
In this thesis, I combine molecular analyses, common-garden and field experiments to examine how evolutionary and ecological processes influence patterns of genetic variation among and within populations of the declining, insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically I examined 1) whether genetic diversity at neutral marker loci was related to habitat fragmentation and habitat stability, 2) whether floral display and flowering time were more strongly differentiated among populations than were putatively neutral marker loci, 3) whether adaptive population differentiation could be detected on a local spatial scale, and 4) whether floral display differentially affected male and female reproductive success.. Genetic diversity at neutral marker loci was lower within fragmented populations on the Swedish mainland than within the more densely occurring populations on the island Öland, SE Sweden. On Öland, fluctuations in population size were more pronounced ...
This week, the MalariaGEN P. falciparum genetic crosses project released a new data resource, comprising whole-genome sequence and genetic variation data from the parents and offspring of three parasite crosses.. This open access resource provides a foundation for further research into how genetic variation and sexual recombination affects parasite biology, at a much higher resolution than previously possible. These data are being made available at a time of intense interest in studying the genetic basis for evolutionary changes in the malaria-causing P. falciparum parasite, such as the emergence and spread of antimalarial drug resistance.. A lot of progress has been made in recent years in mapping out variation in the P. falciparum genome, however there are still big gaps in our knowledge, including many genes that are relevant to vaccine development or drug resistance, explains Alistair Miles, Head of Informatics with the MRC Centre for Genomics and Global Health. These new data on the ...
HIV-1 sequence diversity is affected by selection pressures arising from host genomic factors. Using paired human and viral data from 1071 individuals, we ran ,3000 genome-wide scans, testing for associations between host DNA polymorphisms, HIV-1 sequence variation and plasma viral load (VL), while considering human and viral population structure. We observed significant human SNP associations to a total of 48 HIV-1 amino acid variants (p,2.4 × 10(-12)). All associated SNPs mapped to the HLA class I region. Clinical relevance of host and pathogen variation was assessed using VL results. We identified two critical advantages to the use of viral variation for identifying host factors: (1) association signals are much stronger for HIV-1 sequence variants than VL, reflecting the intermediate phenotype nature of viral variation; (2) association testing can be run without any clinical data. The proposed genome-to-genome approach highlights sites of genomic conflict and is a strategy generally ...
Theories of Population Variation in Genes and Genomes by Christiansen, Freddy Bugge available in Hardcover on, also read synopsis and reviews. This textbook provides an authoritative introduction to both classical and coalescent approaches to...
Leiopotherapon unicolor is the most widespread freshwater fish species in Australia. A comprehensive allozyme and mitochondrial DNA 16S rRNA data set was assembled from 141 specimens of L. unicolor collected Australia-wide in order to test for cryptic speciation in this far-ranging species. Surprisingly, little genetic diversity was observed within L. unicolor and provided no evidence for the existence of cryptic species within this lineage. In contrast, a small sample set of L. aheneus used as the outgroup showed two highly divergent haplotypes strongly suggestive of cryptic speciation. L. unicolor has a number of ecological and life history attributes that may explain the lack of significant genetic divergence over substantial geographical distances. The occurrence of other widespread fish and crustacean species that also display only limited genetic diversity indicate that climate conditions more favourable to dispersal across central and northern Australia than is suggested by the extent of ...
Studies on genetic variation can reveal effects on traits and disease, both in humans and in model organisms. Good technology for the analysis of DNA sequence variations is critical. Currently the development towards assays for large-scale and parallel DNA sequencing and genotyping is progressing rapidly. Single base primer extension (SBE) is a robust reaction principle based on four-colour fluorescent terminating nucleotides to interrogate all four DNA nucleotides in a single reaction. In this thesis, SBE methods were applied to the analysis and discovery of single nucleotide polymorphism (SNP) in the model organism Drosophila melanogaster and in humans.. The tag-array minisequencing system in a microarray format is convenient for intermediate sized genotyping projects. The system is scalable and flexible to adapt to specialized and novel applications. In Study I of the thesis a tool was established to automate quality control of clustered genotype data. By calculating Silhouette scores, the ...
Positive selection distorts the structure of genealogies and hence alters patterns of genetic variation within a population. Most analyses of these distortions focus on the signatures of hitchhiking due to hard or soft selective sweeps at a single genetic locus. However, in linked regions of rapidly adapting genomes, multiple beneficial mutations at different loci can segregate simultaneously within the population, an effect known as clonal interference. This leads to a subtle interplay between hitchhiking and interference effects, which leads to a unique signature of rapid adaptation on genetic variation both at the selected sites and at linked neutral loci. Here, we introduce an effective coalescent theory (a fitness-class coalescent) that describes how positive selection at many perfectly linked sites alters the structure of genealogies. We use this theory to calculate several simple statistics describing genetic variation within a rapidly adapting population and to implement efficient ...
Over the past several years, Genome Wide Association Studies (GWAS) have discovered hundreds of genetic variants involved in complex diseases(10.1056/NEJMra0905980). The vast majority of these variants do not lie in the protein coding regions of genes and thus do not affect what the gene produces, but instead likely affect how the genes are regulated. For this reason, the study of how genetic variation affect gene activity levels (referred to as expression levels) has been a major focus of research for many years. Genetic variation that affects gene expression are referred to as expression quantitative trait loci (eQTL)(10.1038/nrg2969).. Several studies collect expression from multiple tissues which leads to the question of whether or not the same genetic variants affect expression in multiple tissues(10.1038/ng.2653). Another way to ask this question is: Are eQTLs tissue specific or not tissue specific?. A challenge in this type of analysis is that an eQTL may affect expression in multiple ...
Genetic diversity of the human immunodeficiency virus type 1 (HIV-1) population within an individual is lost during transmission to a new host. The demography of transmission is an important determinant of evolutionary dynamics, particularly the relative impact of natural selection and genetic drift immediately following HIV-1 infection. Despite this, the magnitude of this population bottleneck is unclear. We use coalescent methods to quantify the bottleneck in a single case of homosexual transmission and find that over 99% of the env and gag diversity present in the donor is lost. This was consistent with the diversity present at seroconversion in nine other horizontally infected individuals. Furthermore, we estimated viral diversity at birth in 27 infants infected through vertical transmission and found there to be no difference between the two modes of transmission. Assuming the bottleneck at transmission is selectively neutral, such a severe reduction in genetic diversity has important implications
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So traits that have large additive genetic components are more easily changed by selection. The authors set out to investigate the genetic basis of gene expression level in Drosophila (for many genes measured on array) and how this differs between males and females. By a series of crosses, the authors find that many more genes show additive genetic variation in their expression level in males than in females, and that a number of these genes are found on the X chromosome (as well as on the autosomes). Now the X chromosome seems to be be the key to this difference in the form of genetic variation (and the authors conduct further experiments to show this). As males have only a single X chromosome there simply is not any dominance due to genetic variation on the X chromosome (at least not simple non-epistatic dominance). The genetic variation on the X chromosome in males mainly contributes to the additive genetic component of variation (as there is no second allele to cause dominance). So genes on ...
October 3, 2004. October 3, 2004 - In a paper published today in the online edition of Nature Genetics, a deCODE-led team of scientists present the results of a large-scale population study linking recombination rate with maternal age and fertility. In the paper, entitled Recombination rate and reproductive success in humans, the deCODE team establish a novel and significant correlation between recombination - the shuffling of chromosomal material that takes place in the formation of eggs and sperm - and maternal age and fertility. Specifically, the average number of recombinations in eggs that go on to become successful live births tends to increase with the mothers age, and mothers with a higher recombination rate in general also tend to have more children than do those with a lower recombination rate. The authors conclude that the most likely explanation for this phenomenon is that recombination, which is one of the most important mechanisms for generating genetic diversity in ...
Cancer cells are intrinsically heterogeneous. Multiple clones with their unique variants co-exist in tumor tissues. The variants include point mutations and structural variations. Point mutations, or single nucleotide variants are those variants on one base; structural variations are variations involving sequence with length not smaller than 50 bases. Approaches to estimate the number of clones and their respective percentages from point mutations have been recently proposed. However, structural variations, although involving more reads than point mutations, have not been quantitatively studied in characterizing cancer heterogeneity. I describe in this thesis a maximum likelihood approach to estimate variant allele fraction of a putative structural variation, as a step towards the characterization of tumor heterogeneity. A software tool, BreakDown, implemented in Perl realizing this statistical model is publicly available. I studied the performance of BreakDown through both simulated and real ...
The WHI GWAS examines the genome, which is the individuals complete set of DNA, of women who have participated in WHI to see if there are genetic variations associated with a particular disease. To do this, the genomes of women with a particular disease are compared to similar women without the disease. If certain genetic variations are seen in participants with the disease compared to those without, the variations are said to be associated with the disease. The genetic variations themselves do not necessarily cause the disease, but may put individuals with the variant at increased risk. Other influences (diet, smoking, environment) may also be important factors that work along with genetic variations to influence risk. Once new genetic associations are identified, it may be possible to use the information to detect, treat, and prevent the disease. We hope to learn much more about this using the WHI blood samples. ...
Genetic variation in three Iranian pelt sheep breeds namely: Gray Shiraz, Zandi and Karakul were investigated using fifteen microsatellite loci. Genomic DNA was extracted from 360 blood samples by extraction kits and salting-out procedure with some modifications. The total number of alleles ranged from 6 to12 in loci. The fifteen tested loci were all polymorphic in the three breeds. The average direct count of heterozygosity overall loci in each tested breed was more than the expected heterozygosity. Tests of genotype frequencies for deviation from the Hardy-Weinberg equilibrium (HWE) were performed at each locus of overall breeds and revealed significant departure from HWE (P , 0.001) due to heterozygote excess. Polymorphism information content value in Gray Shiraz, Zandi and Karakul were 0.815, 0.808 and 0.808, respectively. Rate of inbreeding within the three breeds was not noticeable (global Fis = - 0.19). Low genetic differentiation was detected by estimation of Fst index between all pairs ...
In 1974, Richard Lewontin published The Genetic Basis of Evolutionary Change, focusing enormous attention on protein variation as both a model of underlying genetic variation and a level of selection itself. In the twenty years since, scientific research has been shifted by the power of molecular biological techniques to explore the nature of variation directly at the DNA and gene levels. The protein chapter is coming to a close. In this book, Jeff Mitton explains the questions that geneticists hoped to answer by studying protein variation. He reviews the extensive literature on protein variation, describes the successes and failures of the research program, and evaluates the results of a rich and controversial body of research. The laboratory and field studies using protein polymorphisms revealed dynamic interactions among genotypes, fitness differentials, and fluctuating environmental conditions, and inadvertently wedded the fields of physiological ecology and population biology. Mittons book is a
The most important biological role of meiosis compared with asexual reproduction is providing genetic diversity of individuals as a result of mixing of paternal and maternal genes in the gamete. This is achieved in two ways.. Firstly, in the first division of meiosis the distribution of paternal and maternal chromosomes into the daughter cells is random, which results in gametes bearing different combinations of parental chromosomes (Smith and Nicolas 204). The second fundamental mechanism for the maintenance of genetic diversity is that in the initial phase of the first meiotic division homologous chromosomes are arranged opposite to each other and couple, forming one or more areas of contact (chiasm) between individual unsisterly chromatids. Next, the pair of chromatids that formed chiasm exchanges the sections of DNA (crossing-over process). As a result of crossing-over recombinant chromosomes are formed consisting of sections originating from different parent lines. Upon the completion of ...
After the recent discovery that common genetic variation in 15q24-25.1 influences inherited risk of lung cancer (3-7), we identified a second sequence variant at 15q24-25.1 associated with familial lung cancer (8) and further validated this new association in large sporadic lung cancer populations. We showed that these two genetic variants on 15q24-25.1 have independent genetic effects on lung cancer risk. The second variant on 15q24-25.1, marked by rs481134, explains an additional 13.2% of the population attributable risk for lung cancer. These results further confirm the complexity of the chromosomal region 15q24-25.1 underlying lung cancer susceptibility.. Interestingly, the second variant did not show association with lung cancer in single-marker analysis. However, haplotype analysis of SNPs rs1051730 and rs481134 provided stronger evidence for association with lung cancer. SNPs rs1051730 and rs481134 are in moderate LD (r2 = 0.30), which can mask or change the genetic effects of those loci ...
The distribution of variation in a quantitative trait and its underlying distribution of genotypic diversity can both be shaped by stabilizing and directional selection. Understanding either distribution is important, because it determines a populations response to natural selection. Unfortunately, existing theory makes conflicting predictions about how selection shapes these distributions, and very little pertinent experimental evidence exists. Here we study a simple genetic system, an evolving RNA enzyme (ribozyme) in which a combination of high throughput genotyping and measurement of a biochemical phenotype allow us to address this question. We show that directional selection, compared to stabilizing selection, increases the genotypic diversity of an evolving ribozyme population. In contrast, it leaves the variance in the phenotypic trait unchanged. ...
"A functional genetic variation of the serotonin (5-HT) transporter affects 5-HT1A receptor binding in humans". The Journal of ...
Advantages due to genetic variation[edit]. See also: Hill-Robertson effect. For the advantage due to genetic variation, there ... Protection from major genetic mutation[edit]. In contrast to the view that sex promotes genetic variation, Heng,[13] and ... Genetic heritability cost of sex[edit]. A sexually reproducing organism only passes on ~50% of its own genetic material to each ... August Weismann picked up the thread in 1889, arguing that sex serves to generate genetic variation, as detailed in the ...
... which are a big part of genetic variation in the human genome, and copy number variation (CNV), pose problems in single cell ... Single-cell resolution can uncover the roles of genetic mosaicism or intra-tumor genetic heterogeneity in cancer development or ... For a gene that is 1kb long, this corresponds to 500 reads and a minimum coefficient of variation (CV) of 4% under the ... "Single-cell RNA-seq reveals hidden transcriptional variation in malaria parasites". eLife. 7: e33105. doi:10.7554/eLife.33105 ...
2007: Human genetic variation. *2008: Cellular reprogramming. *2009: Ardipithecus ramidus. *2010: First quantum machine ... "Genetic Engineering & Biotechnology News. Mary Ann Liebert, Inc. p. 13. Retrieved 2008-07-06. (subtitle) Procymal is being ... Using genetic reprogramming with protein transcription factors, pluripotent stem cells with ESC-like capabilities have been ... Without optimal culture conditions or genetic manipulation,[18] embryonic stem cells will rapidly differentiate. ...
2007: Human genetic variation. *2008: Cellular reprogramming. *2009: Ardipithecus ramidus. *2010: First quantum machine ... Some in the press speculated that a contributing factor to Dolly's death was that she could have been born with a genetic age ...
2007: Human genetic variation. *2008: Cellular reprogramming. *2009: Ardipithecus ramidus. *2010: First quantum machine ...
2007: Human genetic variation. *2008: Cellular reprogramming. *2009: Ardipithecus ramidus. *2010: First quantum machine ...
Weiner, Michael P; Gabriel, Stacey B; Stephens, J Claiborne (2007). Genetic Variation: a Laboratory Manual. Cold Spring Harbor ...
Advantages due to genetic variation[edit]. For the advantage due to genetic variation, there are three possible reasons this ... Protection from major genetic mutation[edit]. In contrast to the view that sex promotes genetic variation, Heng,[11] and ... Genetic heritability cost of sex[edit]. A sexually reproducing organism only passes on ~50% of its own genetic material to each ... August Weismann picked up the thread in 1889, arguing that sex served to generate genetic variation, as detailed in the ...
Barnes, Michael R. (2003). "Human Genetic Variation: Databases and Concepts". In Barnes, Michael R.; Gray, Ian C. ... A single nucleotide polymorphism (SNP), a variation at a single site in DNA, is the most frequent type of variation in the ... SNP-based genetic linkage analysis can be used to map disease loci, and determine disease susceptibility genes in individuals. ... The combination of SNP maps and high density SNP arrays allows SNPs to be used as markers for genetic diseases that have ...
"Mechanisms: Genetic Variation: Types of Mutations". Evolution 101: Understanding Evolution For Teachers. University of ... the truncated proteins frequently are unable to function properly or at all and can possibly result in any number of genetic ...
"Model of Genetic Variation in Human Social Networks" (PDF). Proceedings of the National Academy of Sciences. 106 (6): 1720-1724 ... "Genetic Variation in Political Participation" (PDF). American Political Science Review. 102 (2): 233-248. CiteSeerX ... More recently, he has shown evidence that social networks have a partly genetic basis.[28] In 2010, he published a paper ... the study of the genetic basis of political behavior). He is currently Professor of Medical Genetics in the School of Medicine ...
Human Genetic Variation". Science. 318 (5858): 1842-1843. doi:10.1126/science.318.5858.1842. PMID 18096770. Gretchen Vogel ( ... Human genetic variation Reprogramming cells High-energy cosmic rays Receptor visions Beyond silicon: oxide interfaces Quantum ... Genomes Project an international research effort to establish by far the most detailed catalogue of human genetic variation. ...
"What are variants, alleles and haplotypes? , Human genetic variation". Retrieved 16 November 2020. Seltsam A, Hallensleben M, ... and that a great deal of genetic variation is hidden in the form of alleles that do not produce obvious phenotypic differences ... Allelic variation at a locus is measurable as the number of alleles (polymorphism) present, or the proportion of heterozygotes ... It can also refer to different sequence variations for several-hundred base-pair or more region of the genome that codes for a ...
This narrowing of phenotypes causes a reduction in genetic diversity in a population. Maintaining genetic variation is ... "Low genetic variation". Retrieved 2018-05-13. Linnen CR, Hoekstra HE (2009). "Measuring natural ... "Reconciling strong stabilizing selection with the maintenance of genetic variation in a natural population of black field ... "Variation in Clutch Sizes". Retrieved 2018-05-13. "A Simple Definition and Prominent Examples of Stabilizing ...
Pennisi Elizabeth (2007). "Human Genetic Variation". Science. 318 (5858): 1842-1843. doi:10.1126/science.318.5858.1842. PMID ... A set of aAIMs can be used to identify the ancestry of ancient populations and eventually quantify the genetic similarity to ... NGS enables the study of genetic markers by isolating specific gene sequences. One such method for sequence extraction is the ... Though AIM panels can be useful for disease screening, the Genetic Information Nondiscrimination Act (GINA) prevents the use of ...
Human Genetic Variation". Science. 318 (5858): 1842-1843. doi:10.1126/science.318.5858.1842. PMID 18096770. Gretchen Vogel ( ... Human genetic variation 2008: Cellular reprogramming 2009: Ardipithecus ramidus 2010: The first quantum machine Insights of the ...
"European Genetic Variation". Online maps. Archived from the original on 5 December 2006. Collins, Roger (1990). The Basques ( ... Along the same lines, a genetic study carried out in 2001 revealed that the Y-chromosome of Celtic populations do not differ ... Mattias Jakobsson from Uppsala University in Sweden analysed genetic material from eight Stone Age human skeletons found in El ... Throughout this region, which underwent similar cultural developments with some local variation, Aurignacian culture was ...
For continuous variation in biology, see Genetic variability. For other uses, see Distribution. ...
Honjo T, Habu S (1985). "Origin of immune diversity: genetic variation and selection". Annu Rev Biochem. 54 (1): 803-830. doi: ... Several complex genetic mechanisms have evolved that allow vertebrate B cells to generate a diverse pool of antibodies from a ... These gene segments are then joined together using random genetic recombination to produce the paratope. The regions where the ... Susumu Tonegawa showed that genetic material can rearrange itself to form the vast array of available antibodies.[107] ...
O. volvulus has low genetic variation between individuals. This suggests a population bottleneck occurred in the past that ... This pattern of low genetic variation and high haplotype diversity suggests fast population expansion after a bottleneck and ... This is also supported by genetic data that place O. ochengi (a cattle-infecting strain) as the sister group to O. volvulus.[20 ... "Ivermectin Resistance in Onchocerca volvulus: Toward a Genetic Basis". PLOS Neglected Tropical Diseases. 1 (1): e76. doi ...
Combined with archaic admixture this has resulted in significant genetic variation, which in some instances has been shown to ... Townsend G, Richards L, Hughes T (May 2003). "Molar intercuspal dimensions: genetic input to phenotypic variation". Journal of ... gradually converging into the modern human varieties by the mechanism of clinal variation, via genetic drift, gene flow and ... However, genetic evidence from the Sima de los Huesos fossils published in 2016 seems to suggest that H. heidelbergensis in its ...
Recombination between homeologous chromosomes occurs only rarely, if at all.[68] Since production of genetic variation is weak ... Thus little, if any, genetic variation is produced. ... "Genetic damage, mutation, and the evolution of sex". Science. ... van der Beek, S.; Nielen, A.L.; Schukken, Y.H.; Brascamp, E.W. (1999). "Evaluation of genetic, common-litter, and within-litter ... Leroy, G. (August 2011). "Genetic diversity, inbreeding and breeding practices in dogs: results from pedigree analyses". Vet. J ...
"Genetic Variation and Population Structure in Native Americans". PLoS Genet. 3 (11): e185. doi:10.1371/journal.pgen.0030185. ... Observed is both a decreasing genetic diversity as geographic distance from the Bering Strait occurs and a decreasing genetic ... Wells, Spencer; Read, Mark (2002). The Journey of Man - A Genetic Odyssey (Digitised online by Google books). Random House. pp ... Main article: Genetic history of indigenous peoples of the Americas. See also: Y-DNA haplogroups in indigenous peoples of the ...
And we're now confronted with a persisting aberration, but is it an aberration? It's a genetic variation. So what do we do? I ... "LKY Controversial: LGBT - "It's a genetic variation"". The Online Citizen. 26 March 2015. Retrieved 5 December 2020. "Excerpts ... There's a genetic difference, so it's not a matter of choice. They are born that way and that's that. So if two men or two ... They're born with that genetic code, that's that. Dick Cheney didn't like gays but his daughter was born like that. He says, 'I ...
Nonlethal mutations accumulate within the gene pool and increase the amount of genetic variation. The abundance of some genetic ... In the neutral theory of molecular evolution, neutral mutations provide genetic drift as the basis for most variation at the ... Mutation is the ultimate source of all genetic variation, providing the raw material on which evolutionary forces such as ... A 2007 study on genetic variations between different species of Drosophila suggested that, if a mutation changes a protein ...
Genetic variation Georgitsi, Marianthi; Viennas Emmanouil; Antoniou Dimitris I; Gkantouna Vassiliki; van Baal Sjozef; Petricoin ... FINDbase was founded in 2006 to be a relational database for these frequencies of causative genetic variations of inherited ... The Frequency of INherited Disorders database (FINDbase) is a database of frequencies of causative genetic variations worldwide ... a worldwide database for genetic variation allele frequencies updated". Nucleic Acids Res. 39 (Database issue): D926-32. doi: ...
"Selection, nuclear genetic variation, and mtDNA". john hawks weblog. Retrieved 2011-01-05. Thorne, A.G.; Wolpoff, M.H. (2003 ... Thorne, A.G.; Wolpoff, M. H.; Eckhardt, R.B. (1993). "Genetic variation in Africa". Science. 261 (5128): 1507-1508. Bibcode: ... "Variation in NAT1 and NAT2". john hawks weblog. Retrieved 2011-01-04. Garrigan, D.; Mobasher, Z.; Severson, T.; Wilder, J. A.; ... 2010-12-23). "Genetic history of an archaic hominin group from Denisova Cave in Siberia". Nature. 468 (7327): 1053-60. Bibcode: ...
... intra-clonal genetic variation; rapid evolution in insect populations due to various genetic-ecological mechanisms; population ... underwent increased genetic variation, so did that of its parasitoid. This suggested a fine-grained co-evolutionary tracking to ... 2010) Rapid genetic changes in natural insect populations. Ecological Entomology (special issue) 35, 155-164. Biron DG, Loxdale ... Loxdale has written reviews on absence of strict genetic uniformity in populations of clonal organisms such as aphids. This ...
Genetic Variation and the Natural History of Quaking Aspen. BioScience 46, 1, 25-31. JSTOR ... High levels of genetic variation and excesses of heterozygotes are found in [the aspen of] semi-arid environments... Clonal ... DeWoody, J.; Rowe, C.A.; Hipkins, V.D.; Mock, K.E. (2008). ""Pando" Lives: Molecular Genetic Evidence of a Giant Aspen Clone in ... This collection of multiple stems, called ramets, all form one, single, genetic individual, usually termed a clone. ...
基因組圖譜主要可以分成兩種,一種是遺傳圖譜(genetic map),另一種則是物理圖譜(physical map)。遺傳圖譜是利用基因的重組率來做分析,單位是分莫甘(centimorgan)。這種圖譜表現出來的是基因或特定DNA片段之間的相對
Genetic variation in the key bile acid synthesis enzyme, CYP7A1, influenced the effectiveness of UDCA in colorectal adenoma ... "Bile salts of vertebrates: structural variation and possible evolutionary significance". J. Lipid Res. 51 (2): 226-46. doi ...
A Danish study found that substantial genetic variation between ash trees affected their level of susceptibility.[24] However, ... Ash fungus genetic code unravelled - BBC News *^ a b c "Chalara dieback of ash (Chalara fraxinea)". Forestry Commission. ... Gross, A.; Grünig, C. R.; Queloz, V.; Holdenrieder, O. (2012). "A molecular toolkit for population genetic investigations of ... Genetic analysis of the fungus Lambertella albida which grows harmlessly on petioles of the Manchurian ash (Fraxinus ...
... summarized contemporary thinking about the genetic basis of quantitative natural variation: "As genetic studies continued, ever ... The number of QTLs which explain variation in the phenotypic trait indicates the genetic architecture of a trait. It may ... While schizophrenia is widely believed to be multifactorially genetic by biopsychiatrists, no characteristic genetic markers ... then there is a strong chance that the disease is genetic[citation needed] and that the patient will also be a genetic carrier ...
In search of the genetic footprints of Sumerians: a survey of Y-chromosome and mtDNA variation in the Marsh Arabs of Iraq - - ... Many scholars have proposed historical and genetic links between the Marsh Arabs and the ancient Sumerians based on shared ...
... collaborations with both Laboratory Corporation and Quest Diagnostics to develop a solution for scoring genetic variation for ...
There are many regional variations on the rhyme, which means that it is impossible to give a definitive version.[50][52] ... Importance of habitat preference and breeding behavior on genetic structure in China". Molecular Phylogenetics and Evolution. ... The gradual clinal variation over the large geographic range and the intergradation of the different subspecies means that the ... but show much variation in ground and marking.[31] ...
Owing to their highly 'malleable' genetic code, mallards can display a large amount of variation,[36] as seen here with this ... Genetic analysis has shown that certain mallards appear to be closer to their Indo-Pacific relatives while others are related ... Mallards are causing severe "genetic pollution" to South Africa's biodiversity by breeding with endemic ducks[113] even though ... Due to the variability of the mallard's genetic code, which gives it its vast interbreeding capability, mutations in the genes ...
"Mobile Genetic Elements. 3 (4): e25845. doi:10.4161/mge.25845. PMC 3812789. PMID 24195014.. ... Chloroplast transit peptides exhibit huge variation in length and amino acid sequence.[42] They can be from 20-150 amino acids ... It further contends that only a minority of the genetic material is kept in circular chromosomes while the rest is in branched ...
In spite of regional variations, around 80% of the females give birth to their calves within a period of 2-3 weeks after the ... Corbet, S. W.; Robinson, T. J. (November-December 1991). "Genetic divergence in South African Wildebeest: comparative ...
These gene candidates include certain variations in tumor necrosis factor-alpha (TNF-alpha), IL-1 alpha, and CYP1A1 genes, ... Acne can be a feature of rare genetic disorders such as Apert's syndrome.[15] Severe acne may be associated with XYY syndrome.[ ... Acne appears to be strongly inherited; genetics explain 81% of the variation in the population.[15] Studies performed in ... among others.[19] The 308 G/A single nucleotide polymorphism variation in the gene for TNF is associated with an increased risk ...
They have combined molecular and genetic approaches to answer some of Darwins key questions about the natural variation of ... For his numerous contributions to the exact study of heredity & variation contained in Hereditary Genius, Natural Inheritance, ... of his discovery of somatic recombination in fungi which led to the elucidation of an important type of genetic variation. ... For his important contribution to the theory of organic evolution by his researches on variation and heredity. ...
... we need massive amounts of genetic sequencing. Not just for new cases, but we need to go back and sequence old cases - from ... we can expect a fair amount of temperature dependent variation in this number. For example, at 55 °C, among the hottest ever ...
"Genetic variation and recent positive selection in worldwide human populations: evidence from nearly 1 million SNPs". PLOS ONE ... Those variations are called alleles. While some genes have only one allele because there is low variation, others have only one ... Sometimes, one allele is a disease-causing variation while the other allele is healthy. Sometimes, the different variations in ... In cultured mammalian cells, such as the Chinese hamster ovary cell line, a number of genetic loci are present in a functional ...
The genetic network logic responds to signals received from the environment and from internal cell status sensors to adapt the ... There is similar random variation in the rates of progression of all the other subsystem reaction cascades. The net effect is ... The genetic basis of the phenotypic differences between the two strains results from coding, regulatory, and insertion/deletion ... The central feature of the cell cycle regulation is a cyclical genetic circuit-a cell cycle engine-that is centered around the ...
There are variations from country to country regarding which specialties certain subspecialties are in. ... as the causative genes of most monogenic genetic disorders have now been identified, and the development of techniques in ... transcription and translation of the genetic material. ...
Genetic skeletal dysplasias also known as osteochondrodysplasia usually manifest in short-limbed disproportionate short stature ... From a medical perspective, severe shortness can be a variation of normal, resulting from the interplay of multiple familial ... The deficiency may be genetic. Among children without growth hormone deficiency, short stature may be caused by Turner syndrome ... On the other hand, most genetic skeletal dysplasias are known for short stature that may be proportionate or disproportionate. ...
... complexity allows the parasite to constantly change its surface and thus evade the immune system through antigenic variation.[ ...
Is it a new tick borne disease or Lyme disease variation?". Brazilian Journal of Medical and Biological Research = Revista ... Polymerase chain reaction (PCR) tests for Lyme disease have also been developed to detect the genetic material (DNA) of the ... antigenic variation of the VlsE surface protein, inactivating key immune components such as complement, and hiding in the ... this is more common after infection by certain Borrelia strains in people with certain genetic and immunologic characteristics. ...
Wild Lens species are a significant source of genetic variation for improving the relatively narrow genetic base of this crop. ... Serious genetic improvement for yield has been made, however, the full potential of production and productivity could not yet ... Although lentils have been an important crop for centuries, lentil breeding and genetic research has a relatively short history ...
Darwin, Charles (1868). The Variation of Animals and Plants under Domestication. Volume 1 (1st ed.). London: John Murray. pp. ... Genetic considerationsEdit. The wolf-like canids are a group of large carnivores that are genetically closely related because ... In The Variation of Animals and Plants under Domestication Charles Darwin wrote: ... Documenting Domestication:New Genetic and Archaeological Paradigms. University of California Press. pp. 279-295. ISBN ...
This compares with 25% of Cw7-B7 that extend to A3::DQ6 [4] Of 25 potential genetic recombinants of A1::DQ2, none exceed 10% of ... "Variation analysis and gene annotation of eight MHC haplotypes: the MHC Haplotype Project". Immunogenetics. 60 (1): 1-18. doi ... June 2004). "Genetic polymorphisms in tumor necrosis factor (TNF)-alpha and TNF-beta in a population-based study of systemic ... February 1999). "The genetic basis for the association of the 8.1 ancestral haplotype (A1, B8, DR3) with multiple ...
However, studies examining the incidence of malignant central nervous system (CNS) tumors have shown some variation with ... and follow-up examination of prepared tissues after immunohistochemical staining or genetic analysis. ... with subtle variations in color. Three separate brain areas make up most of the brain's volume: *telencephalon (cerebral ...
"Genetic variation in the progesterone receptor gene and ovarian cancer risk". American Journal of Epidemiology. 161 (5): 442-51 ...
2: genetic aspects of alpha(1)-antitrypsin deficiency: phenotypes and genetic modifiers of emphysema risk". Thorax. 59 (3): 259 ... Carrell RW, Jeppsson JO, Laurell CB, Brennan SO, Owen MC, Vaughan L, Boswell DR (July 1982). "Structure and variation of human ... a new paradigm for hepatocellular carcinoma in genetic liver disease". Hepatology. 42 (3): 514-21. doi:10.1002/hep.20815. PMID ... Lessons from descriptive studies and analyses of genetic and environmental risk determinants". Clinical and Experimental ...
Van Parijs, Sofie M.; Hastie, Gordon D.; Thompson, Paul M. (2000-03-01). "Individual and geographical variation in display ... the continuance of their genetic line. ...
Ramel, C (1998). "Biodiversity and intraspecific genetic variation". Pure and Applied Chemistry. 70 (11): 2079-2084. CiteSeerX ... "Genetic Evaluation Results". Archived from the original on August 27, 2001.. *^ S1008: Genetic Selection and Crossbreeding to ... With continuous inbreeding, genetic variation is lost and homozygosity is increased, enabling the expression of recessive ... "Genetic diversity and population genetic structure in the South American sea lion (Otaria flavescens)" (PDF). Department of ...
... describes the genetic effect of a single gene on multiple phenotypic traits. The underlying mechanism is genes that ... They also propose the idea that pleiotropy increases the phenotypic variation of both traits since a single mutation on a gene ... Sickle cell anemia is a genetic disease that causes deformed red blood cells with a rigid, crescent shape instead of the normal ... This mathematical model illustrates how evolutionary fitness depends on the independence of phenotypic variation from random ...
By using temperature variations in their surroundings, or by remaining cold when they do not need to move, reptiles can save ... All genetic studies have supported the hypothesis that turtles are diapsids; some have placed turtles within archosauriformes,[ ... This variation in blood flow has been hypothesized to allow more effective thermoregulation and longer diving times for aquatic ... The cladogram below used a combination of genetic (molecular) and fossil (morphological) data to obtain its results.[25] ...
Keller, A; Zhuang, H; Chi, Q; Vosshall, LB; Matsunami, H (2007-09-27). "Genetic variation in a human odorant receptor alters ... ISBN 0-7817-6003-8. Menashe, I; Abaffy, T; Hasin, Y; Goshen, S; Yahalom, V; Luetje, CW; Lancet, D (2007-10-30). "Genetic ... The causes of hyperosmia may be genetic, environmental or the result of benzodiazepine withdrawal syndrome. When odorants enter ... There has not yet been extensive research into the genetic background of those with general hyperosmia, rather than for just a ...
Some differences between phonemic and genetic variation are also evident in Fig. 1 B-D. For example, the South American genetic ... The association between genetic variation and phonemic variation was largely explained by the geographic distribution of ... Worldwide human phonemic and genetic variation. Nicole Creanza, Merritt Ruhlen, Trevor J. Pemberton, Noah A. Rosenberg, Marcus ... Worldwide human phonemic and genetic variation. Nicole Creanza, Merritt Ruhlen, Trevor J. Pemberton, Noah A. Rosenberg, Marcus ...
Distribution of variation[edit]. Human genetic variation calculated from genetic data representing 346 microsatellite loci ... Structural variation[edit]. Main article: Structural variation. Structural variation is the variation in structure of an ... Measures of variation[edit]. Genetic variation among humans occurs on many scales, from gross alterations in the human ... Human genetic variation is the genetic differences in and among populations. There may be multiple variants of any given gene ...
Genetic variation across the human olfactory receptor repertoire alters odor perception C. Trimmer, A. Keller, N. R. Murphy, L ... Genetic variation in chromosome Y regulates susceptibility to influenza A virus infection *From the Cover ...
IntroductionGenetic Variation and Natural SelectionIntroductionNatural SelectionPost-Mendelian Inheritance FactorsThis section ... Genetic Variation and Natural Selection: Introduction. Introduction. Genetic Variation and Natural Selection. *Introduction ...
AND FSTGEOGRAPHIC DISTANCE AND THE PATTERN OF GENETIC VARIATIONBIBLIOGRAPHY Source for information on Genetic Variation Among ... Genetic Variation Among PopulationsTHE APPORTIONMENT OF VARIATIONVARIATION AMONG POPULATIONS (FST)ESTIMATES OF FST FOR ... THE APPORTIONMENT OF VARIATION. One of the main interests in studies of genetic variation is the question of how variation is ... SEE ALSO Clines and Continuous Variation; Clines and Continuous Variation; Forensic Anthropology and Race; Gene Pool; Genetic ...
Genetic Mutations of the Year. A website highlights common genetic variations that made a splash in 2009. ... Handled with care, the new "HapMap" of genetic variation could reveal the genetic roots of many diseases. ... Common Genetic Variants Have Little Effect on Breast Cancer Prediction. The types of genetic factors identified in direct to ...
Adaptation from standing genetic variation.. Barrett RD1, Schluter D.. Author information. 1. Department of Zoology and ... Populations adapt to novel environments in two distinct ways: selection on pre-existing genetic variation and selection on new ... Compared with new mutations, adaptation from standing genetic variation is likely to lead to faster evolution, the fixation of ... Understanding how the source of genetic variation affects adaptation will be integral for predicting how populations will ...
Three primary sources of genetic variation: Mutations, Gene flow, Sex (genetic shuffling). ... Resource that describes how genetic variation drives some of the basic mechanisms of evolutionary change. ... Three primary sources of genetic variation: Mutations, Gene flow, Sex (genetic shuffling). ... Three primary sources of genetic variation: Mutations, Gene flow, Sex (genetic shuffling). ...
Variation at the Esh locus was associated with a continuum from cold-wet to hot-dry. Variation at the Mdh locus and some of ... MULTIVARIATE ANALYSIS OF GENETIC VARIATION. Charles E. Taylor and Jeffry B. Mitton ... MULTIVARIATE ANALYSIS OF GENETIC VARIATION. Charles E. Taylor and Jeffry B. Mitton ... MULTIVARIATE ANALYSIS OF GENETIC VARIATION. Charles E. Taylor and Jeffry B. Mitton ...
85% of genetic variation is within groups…. Posted by Razib Khan on February 23, 2008 ... On a typical single locus (on some loci, such as SLC24A5, most of the variation is between groups). But that doesnt mean that ... So what? This is just collapsing variation due to successive bottlenecks. Thats hardly interesting in terms of the actual " ... From Worldwide Human Relationships Inferred from Genome-Wide Patterns of Variation. Also see Lewontins Fallacy. ...
Adults with a genetic variation enabling them to express higher levels of fetal hemoglobin may have a reduced risk of ... Adults with a genetic variation enabling them to express higher levels of fetal hemoglobin may have a reduced risk of ... Genetic variation may reduce Alzheimers risk. Medical College of Georgia at Augusta University ... To determine the impact of the genetic mutation on Alzheimers risk, studies need to be done on more Alzheimers patients and ...
A global reference for human genetic variation.. 1000 Genomes Project Consortium, Auton A, Brooks LD, Durbin RM, Garrison EP, ... The 1000 Genomes Project set out to provide a comprehensive description of common human genetic variation by applying whole- ... We describe the distribution of genetic variation across the global sample, and discuss the implications for common disease ... We characterized a broad spectrum of genetic variation, in total over 88 million variants (84.7 million single nucleotide ...
... News-Medical. ... Complex patterns of genetic ancestry can provide insights into genetic, environmental factors of many diseases ... and in-silico methods were utilized to identify two common genetic variations correlated with shorter disease period. ... ...
Our study of the transmission of polymorphic genetic markers in natural isolates of Glomus etunicatum, coupled with direct ... Here we report a genetic approach to test the hypothesis of heterokaryosis in AM fungi. ... Organization of genetic variation in individuals of arbuscular mycorrhizal fungi. *Teresa E. Pawlowska. 1. & ... Pawlowska, T., Taylor, J. Organization of genetic variation in individuals of arbuscular mycorrhizal fungi. Nature 427, 733-737 ...
By mapping differences in transcription factor binding among individuals, here we present the genetic basis of such variation ... We showed that most transcription factor binding variation is cis-linked, and that many variations are associated with ... and the underlying genetic loci responsible for variation in its binding are mapped. The study reveals new insights into the ... Variation in the regulation of gene transcription between individuals is thought to be a major cause of phenotypic diversity. ...
This creates a continuum of variation. If this polygenic explanation... ... This creates a continuum of variation. If this polygenic explanation for the inheritance of human skin pigmentation is correct ... Related Threads for: Genetic variation question Evolution Homework - Genetic Variation *Last Post ...
First, this involves creating a systematic catalog of the full range of genetic variants (large and small, rare and common) ... Understanding the pattern of common genetic variation in the human population is a major focus of the program. ... Understanding the pattern of common genetic variation in the human population is a major focus of the program. First, this ... it becomes possible to undertake systematic studies of the genetic factors underlying inherited susceptibility to common ...
... selection on pre-existing genetic variation and selection on new mutations. These alternative sources of beneficial alleles can ... result in different evolutionary dynamics and distinct genetic outcomes. Compared with new mutations, adaptati … ... Adaptation from standing genetic variation Trends Ecol Evol. 2008 Jan;23(1):38-44. doi: 10.1016/j.tree.2007.09.008. Epub 2007 ... Populations adapt to novel environments in two distinct ways: selection on pre-existing genetic variation and selection on new ...
Genetic variation in dopaminergic activity is associated with the risk for psychiatric side effects of levetiracetam. *C. H ... C., H., Y., M., M.R., T., H., T., P., N., S., S., … W.S., K. (2013). Genetic variation in dopaminergic activity is associated ... the findings provide first evidence of an association of genetic variation in dopaminergic activity and the risk for ... To assess the genetic basis of the adverse psychotropic profile of LEV, a candidate gene-based two-stage association study was ...
Alcoholism, genetics, Body Mass Index, Family Health, Female, Genetic Predisposition to Disease, Genetic Variation, Genotype, ... Genetic variation of the ghrelin signaling system in females with severe alcohol dependence. Artikel i vetenskaplig tidskrift ... Known gender differences in plasma ghrelin levels prompted us to investigate genetic variation of the ghrelin signaling system ...
... 20.09.2007. Mark Twain boasted that it was easy to quit smoking because ... A new study being published in the September 15th issue of Biological Psychiatry reports that genetic variation in a particular ... Innovative genetic tests for children with developmental disorders and epilepsy 11.07.2018 , Christian-Albrechts-Universität zu ... when doctors are able to use genetic information about their patients to guide treatment. We are not ready to use this ...
Genetic Variation. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 ... function, as in human genetic diseases like sickle cell anaemia,. through marginal or neutral effects to functional ...
... depleting the genetic variation upon which it acts. Sexually antagonistic (SA) genetic variation-in which alternative alleles ... Here, we show that the SA genetic variation underlying fitness in a well-known seed beetle population exhibits these beneficial ... suggesting SA selection may commonly maintain heritable genetic variation for fitness throughout the genome. ... have opposite fitness effects in the sexes-can generate balancing selection that maintains genetic variation for fitness if the ...
... EurekAlert! ^ , October 3, 2018 , Stockholm University Posted ... The genetic variation within the Scythian nomad group is so broad that it must be explained with the group assimilating people ... Even though a couple of the groups had an early history somewhere else all the groups share genetic background and follow each ...
Genetic variation and random drift in autotetraploid populations. Message Subject (Your Name) has forwarded a page to you from ... Genetic variation and random drift in autotetraploid populations.. M E Moody, L D Mueller and D E Soltis ... Genetic variation and random drift in autotetraploid populations.. M E Moody, L D Mueller and D E Soltis ... Genetic variation and random drift in autotetraploid populations.. M E Moody, L D Mueller and D E Soltis ...
Rieseberg, L. H., Soltis, D. E., & Soltis, P. S. (1988). Genetic Variation in Helianthus annuus and H. bolanderi. Biochemical ... A transcriptomic approach was employed using a cDNA microarray of 9058 C. gigas clones to highlight the genetic expression ... This is the first study employing microarrays to characterize the genetic markers and metabolic pathways responding to hypoxic ...
Researchers at Childrens Hospital of Philadelphia have pinpointed a genetic variation responsible for driving the development ... have pinpointed a genetic variation responsible for driving the development of inflammatory bowel disease (IBD). The genetic ... Researchers pinpoint genetic variation responsible for development of IBD. *Download PDF Copy ... Researchers discover genetic risk factors for childhood OCD. *Japanese-European scientists detect novel genetic mitochondrial ...
Crossing over creates genetic variation by exchanging DNA between two nonsister chromatids to produce genetically unique ... Crossing over creates genetic variation by exchanging DNA between two nonsister chromatids to produce genetically unique ... These gametes contain 23 chromosomes, which is half of the genetic information of the parent. During fertilization, a zygote is ... The two ways wherein meiosis increases genetic diversity in a species are crossing over and independent assortment of ...
To investigate genetic causes of metabolome variation, we measured th … ... The genetic factors responsible for inter-individual metabolic variability remain poorly understood. ... Genetic basis of metabolome variation in yeast PLoS Genet. 2014 Mar 6;10(3):e1004142. doi: 10.1371/journal.pgen.1004142. ... To investigate genetic causes of metabolome variation, we measured the concentrations of 74 metabolites across ~ 100 segregants ...
Lumpy genetic variation. Posted on May 22, 2014. November 30, -0001. by Razib Khan ... For example genetic variation across distance increases sharply at the Himalaya mountain range. Obviously there is admixture ... Ill focus on one aspect of Jennifers exposition: that human genetic variation is clinal. This is a defensible position, and ... The genetic distance is then simply a function of time since divergence, as well as the magnitude of gene flow (which is ...
  • On a global scale, both genetic distance and phonemic distance between populations are significantly correlated with geographic distance. (
  • Furthermore, although geographically isolated populations lose genetic diversity via genetic drift, phonemes are not subject to drift in the same way: within a given geographic radius, languages that are relatively isolated exhibit more variance in number of phonemes than languages with many neighbors. (
  • Human genetic variation is the genetic differences in and among populations . (
  • The differences between populations represent a small proportion of overall human genetic variation. (
  • Populations also differ in the quantity of variation among their members. (
  • There are at least three reasons why genetic variation exists between populations. (
  • Serial founder effects and past small population size (increasing the likelihood of genetic drift) may have had an important influence in neutral differences between populations. (
  • First, how much variation exists among populations, relative to the amount of variation within populations? (
  • Second, what is the pattern of genetic variation among populations? (
  • That is, are all populations equally related-and if not, what are the geographic and historical factors that have influenced the genetic relationship among populations? (
  • One of the main interests in studies of genetic variation is the question of how variation is apportioned both within and among populations. (
  • In other words, if a species is considered as made up of a number of different populations, how much of the total variation in the species exists within each population, and how much variation exists among all the populations? (
  • Variation among populations refers to the level of differences between two or more populations. (
  • If two populations were genetically the same, then there would be no variation among the populations. (
  • The more different the populations are from each other, the greater the level of variation among the populations. (
  • Populations adapt to novel environments in two distinct ways: selection on pre-existing genetic variation and selection on new mutations. (
  • Here we review these approaches and possible examples of adaptation from standing variation in natural populations. (
  • Understanding how the source of genetic variation affects adaptation will be integral for predicting how populations will respond to changing environments. (
  • Here are 938 individuals (the points) from 51 world populations (the color of the points) displayed on a figure with the two largest principle components of the variation. (
  • The 1000 Genomes Project set out to provide a comprehensive description of common human genetic variation by applying whole-genome sequencing to a diverse set of individuals from multiple populations. (
  • Genetic variation and random drift in autotetraploid populations. (
  • The rate of decay of genetic variation is determined for randomly mating autotetraploid populations of finite size, and the equilibrium homozygosity under mutation and random drift is calculated. (
  • A method of comparing genetic variation between autotetraploid and diploid populations is proposed. (
  • Our treatment suggests that the "gametic homozygosity" provides a unified approach for comparing genotypes within a population as well as comparing genetic variation between populations with different levels of ploidy. (
  • Two exceptions to the pattern include the Hazara and Uygur populations, from Pakistan and western China, respectively, whose genetic distances scale continuously with geographic distance both for populations in Eurasia and for those in East Asia. (
  • Includes basic single-locus descriptive statistics, Wright's F-statsistics for subdivided populations, Genetic distance measures, and exact tests for disequilibrium. (
  • Genetic variation is the difference in DNA among individuals or the differences between populations. (
  • Geographic variation means genetic differences in populations from different locations. (
  • A variety of factors maintain genetic variation in populations. (
  • Cheetah populations have low amounts of genetic variation, while lion populations typically have higher amounts. (
  • Laboratory populations that quietly amass 'cryptic' genetic variants are capable of surprising evolutionary leaps, according to a paper in the July 26 issue of Science. (
  • Genetic variation , variation in alleles of genes, occurs both within and among populations. (
  • Resequencing of coding regions in many human samples from different populations can be a powerful approach to finding variants that may affect gene expression, but this approach will not find the large number of variants outside of coding regions that could play an important role in gene expression nor will it fine several types of non-SNP variation such as large repeats or deletions, etc. (
  • A genetic paradox exists in invasion biology: how do introduced populations, whose genetic variation has probably been depleted by population bottlenecks, persist and adapt to new conditions. (
  • Genetic analyses indicate that at least eight introductions have occurred in Florida from across this lizard's native range, blending genetic variation from different geographic source populations and producing populations that contain substantially more, not less, genetic variation than native populations . (
  • Moreover, recently introduced brown anole populations around the world originate from Florida, and some have maintained these elevated levels of genetic variation. (
  • But, these originally isolated genetic populations came into contact and mixed, producing genetically varied descendent populations. (
  • More than 130 leading population geneticists are publicly condemning a book arguing that genetic variation between human populations could underlie global economic, political and social differences. (
  • Genetic diversity in nature , i.e., molecular genetic hereditary differences within and between populations and species, is the basis of evolutionary change (Darwin, 1859). (
  • Extensive molecular genetic diversity has been revealed in natural populations since its early discovery in enzymes (Markert and Moller, 1959), proteins (Zuckerkandl and Pauling, 1965), isozymes/allozymes (Lewontin, 1974), and DNA (Kimura, 1983). (
  • Protein and DNA variation in nature do not primarily reflect evolutionary noise entering into populations through mutational input and random fixation, as maintained by the neutrality theory of molecular evolution (Kimura, 1983). (
  • Various forms of natural selection, primarily through the mechanisms of spatiotemporally varying environments and epistasis as well as balancing, directional, diversifying, frequency - dependent and purifying selection regimes are massively involved in genetic structure and divergence of populations (Nevo, 1998), including small populations (Nevo et al. (
  • In this thesis, I combine molecular analyses, common-garden and field experiments to examine how evolutionary and ecological processes influence patterns of genetic variation among and within populations of the declining, insect-pollinated, self-incompatible, perennial herb Primula farinosa . (
  • More specifically I examined 1) whether genetic diversity at neutral marker loci was related to habitat fragmentation and habitat stability, 2) whether floral display and flowering time were more strongly differentiated among populations than were putatively neutral marker loci, 3) whether adaptive population differentiation could be detected on a local spatial scale, and 4) whether floral display differentially affected male and female reproductive success. (
  • Genetic diversity at neutral marker loci was lower within fragmented populations on the Swedish mainland than within the more densely occurring populations on the island Öland, SE Sweden. (
  • However, it is generally not used by plant breeders, due to the complexity of phenotyping genetic mapping populations. (
  • At the Laboratory of Genetics we have developed genetic tools, analyses and populations in order to overcome such difficulties. (
  • The methods that are employed in this study are firstly genetic mapping, in CSLs or using novel algorithm that allow the detection of epistasis in large GWAS populations. (
  • Postdoctoral Position Ecological relevance of a natural genetic variation in root system morphology in Arabidopsis thaliana The phenotypic variation observed between individuals or populations is partly the result of exposure to different environments and partly the result of genetic differences. (
  • Donnelly has also developed a fundamental framework for analysing genome data that is leading to conclusions about human evolution, and even early human history, by tracking the migrations of populations through the variations in their genes. (
  • Most genetic research has used inbred organisms and has not explored the complexity of natural genetic variation present in outbred populations. (
  • The effect of this situation is an increased genetic differentiation from other populations, as it was observed through autosomal and Y chromosome markers. (
  • Very low FST values indicated that there was no significant genetic differentiation between adjacent old growth and second growth populations at each location. (
  • Genetic diversity was moderate to high in populations north of the San Francisco Bay but low to very low in more southerly populations. (
  • Differentiation of these two groups is consistent with the loss of rare alleles in the smaller, more fragmented southern populations by genetic drift. (
  • Recent natural selection took the genetic code in different directions as different populations adapted to their local environments, the scientists found. (
  • The sequence in Han Chinese populations had an evolutionarily new variation, perhaps reflecting that premature birth would have been especially costly for the small group of ancestral humans who migrated from Africa to East Asia. (
  • The findings also predict that the genetic forms of the progesterone receptor seen in East Asians would not necessarily protect against premature birth in other populations. (
  • African-American women who had genetic variants typically seen in East Asian populations had a higher risk of premature birth, the study found. (
  • Genetic data like this documents us many human populations practiced patrilocal residence , which is a term anyone well versed in socio-cultural anthropology would know by heart. (
  • For the most part human populations have been paternal and this genetic data supplements the ethnographic, archaeological, and historical data. (
  • Thus, although languages and genes are transmitted differently, combining linguistic and genetic analyses is a natural approach to studying human evolution ( 1 , 2 ). (
  • Molecular evidence for genetic exchanges among ribosomal genes on nonhomologous chromosomes in man and apes. (
  • Ste12 binding strongly correlates with gene expression for more than 200 genes, indicating that binding variation is functional. (
  • These results highlight specific examples of genetic variability, including in genes without prior known metabolic regulatory function, that impact yeast metabolism. (
  • Less clear is a possible association between more common variations in these genes known as polymorphisms, and the formation of breast cancer. (
  • The Hirshfield laboratory previously reported on polymorphisms in p53 tumor suppressor pathway genes that associate age with diagnosis of breast cancer and on how these associations depend on the genetic and environmental characteristics of breast cancer. (
  • Ultimately, genetic variation is caused by variation in the order of bases in the nucleotides in genes. (
  • Examination of DNA has shown genetic variation in both coding regions and in the non-coding intron region of genes. (
  • Geneticists study how different genetic profiles affect how certain genes are turned on or off in different people, which could be the cause of a number of genetic disorders. (
  • The richness of genetic variation that affects the regulation of most of our genes surprised us,' says study coordinator Tuuli Lappalainen, previously at UNIGE and now at Stanford University. (
  • The study identified seven novel genetic risk loci that include genes involved in host defense, cell-cell adhesion, and DNA repair. (
  • The researchers also performed population genetic analysis of rgba-1 and npr-28 and found that the two genes might have been subjected to a recent selective sweep, a natural selection process that leads to the reduction or elimination of genetic variations among individuals. (
  • This research indicates that aging rates may have been affected by the emergence of new genes, natural selection, and interaction between different genetic loci, thus providing new insights into the evolutionary theory of aging. (
  • Genetic Variants in the LEPR, CRY1, RNASEL, IL4, and ARVCF Genes Are Prognostic Markers of Prostate Cancer-Specific Mortality. (
  • In the team's latest analysis of the exomes from around the world- presented in part at a genomics conference in 2015-the team highlighted the utility of the large dataset to identify rare disease-causing variants and genes that are particularly sensitive to mutational variation, including loss of function. (
  • Separately, Walsh and colleagues from Imperial College London and the University of Oxford, U.K., have demonstrated the utility of the amassed genetic information for evaluating genes involved in multigenic heritable diseases. (
  • By focusing on confirmed genes, we expect this study to improve the clinical genetic testing of cardiomyopathies by reducing the number of uncertain and even false positive results," wrote Walsh. (
  • The widespread occurrence of structural variation and the observation that many genes are affected, suggests that SV is likely to be a major form of human variation. (
  • Furthermore, its complex genetic architecture constrains pinpointing the causal genes or genetic interactions that may contribute to this trait. (
  • Of special interest is epistasis, interaction between genetic loci (Fig. 1), which is expected to play a big role in photosynthesis due the total number of genes that are involved but remains elusive. (
  • We have exploited natural genetic variation to isolate a novel regulator of root system morphology in the model plant system Arabidopsis thaliana, the BREVIS RADIX (BRX) gene (Mouchel, Briggs & Hardtke 2004, Genes & Development, 18: 700-714). (
  • This is what the HapMap project is about, and Donnelly is at the forefront of looking at the variation of genes within the human species - to try and find out what is really relevant to disease. (
  • The buffering of variation in one gene is most often due to a small number of other genes that function in the same biochemical process. (
  • It is hardly a leap of faith to assume that, just as model organisms have been instrumental in defining the roles of genes and the structure of genetic pathways that are important for human disease, they will be equally useful in defining the principles of gene interaction. (
  • Moreover, experimental organisms may be even more useful for discovering gene interactions than for the characterization of the functions of individual genes, because the power resulting from genetic tractability will be compounded in studies of gene interaction. (
  • In functional genetic studies, the microarray profiling for differentially expressed ovarian genes and candidate gene approach is utilized to define the variation in reproductive success, litter size in particular. (
  • Using novel molecular techniques, they were able to further map the connections between enhancer regions and their target genes, providing insights into how variations in enhancer regions can affect downstream gene expression in specific cell types. (
  • We combined gene variation and expression data in a human cohort to identify causal genes. (
  • This observation underscores the complexity of human transcriptional regulation and highlights the utility of large human cohorts in which both genetic variation and global gene expression data are available to identify disease genes. (
  • Expedient identification of genes mediating the effects of genome-wide association study-identified loci will enable mechanism-of-action studies and accelerate understanding of human disease processes under genetic influence. (
  • In this study, we analyze the San Antonio Family Heart Study (SAFHS), where large-scale gene expression and variation measurements have been undertaken in the same individuals ( 6 ) and demonstrate its utility in identification of genes mediating the consequences of biological variation. (
  • Human genetic variation has been studied for quite sometime and the primary reason to study genetic variation in humans is to discover and describe the linkage of genes to many human diseases. (
  • Radiation from cell phones is associated with higher rates of thyroid cancer among people with genetic variations in specific genes, a new study led by the Yale School of Public Health finds. (
  • The data are discussed in terms of the coexistence of impulsivity and hyperactivity, interactions between environmental and genetic effects, and possible candidate genes. (
  • A curated database of genes associated with dietary restriction in model organisms either from genetic manipulation experiments or gene expression profiling. (
  • 99.9%) of these sites are small differences, either single nucleotide polymorphisms or brief insertions or deletions ( indels ) in the genetic sequence, but structural variations account for a greater number of base-pairs than the SNPs and indels. (
  • We characterized a broad spectrum of genetic variation, in total over 88 million variants (84.7 million single nucleotide polymorphisms (SNPs), 3.6 million short insertions/deletions (indels), and 60,000 structural variants), all phased onto high-quality haplotypes. (
  • They examined single-nucleotide polymorphisms (SNPs) - variations in just one 'letter' of a person's DNA sequence that are often linked to inherited characteristics - including a raised or lowered risk of cancer. (
  • Professor Doug Easton, director of Cancer Research UK's Genetic Epidemiology Unit at the University of Cambridge, said: "Work by Cancer Research UK and others has uncovered over 30 SNPs that are associated with prostate cancer risk. (
  • First, they looked at genome-wide association data from 1,376 French individuals and identified 16,360 single-nucleotide polymorphisms (SNPs), or genetic variations, associated with type 2 diabetes. (
  • Discovering and typing single nucleotide polymorphisms (SNPs), indels, and other forms of genetic variation on a large scale across the genome. (
  • Developing methods for the large-scale experimental and statistical analysis of SNPs, other forms of genetic variation, haplotypes, and complex traits. (
  • Since the sequencing of the human genome, biologists have been charting minute variations as small as one base, called single-nucleotide polymorphisms (SNPs). (
  • Controversies included allozyme and DNA markers (RAPDs, AFLPs, SSRs, see glossary ), and currently include the basic units of genetic diversity, i.e., single nucleotide polymorphisms (SNPs) and copy number variation (CNV), which are both abundant in nature and largely enigmatic as to their functional significance. (
  • Intended for graduate students and professional scientists in clinical and research settings, it covers the complete spectrum of genetic variation from SNPs and microsatellites to more complex DNA alterations, including copy number variation. (
  • However, the study published today suggests that structural variation is responsible for a larger number of differences between the genomes of two individuals than SNPs. (
  • The importance of genetic variation for understanding human disease is increasingly appreciated, as exemplified by the large-scale public and private initiatives aiming to identify hundreds of thousands of SNPs (single-nucleotide polymorphisms) along the human genome. (
  • SNPs serve as genetic markers and potentially identify variant alleles that contribute to phenotypic traits ( 1 , 2 ). (
  • Watch this video to learn about single nucleotide polymorphisms (SNPs), normal variation within the human genome and how we are beginning to understand that SNPs have a key role in disease development and our response to medicines. (
  • Information on participants' use of aspirin, NSAIDs or both was collected in each study, and the researchers investigated how the medications interacted with single-nucleotide polymorphisms (SNPs) - DNA sequence variations - among participants and how this influenced their risk of colorectal cancer. (
  • SNPs are a form of genetic variation, in that a SNP is the difference of one base pair in the same location between two or more alleles. (
  • 0:08 Skip to 0 minutes and 8 seconds Genetic variation. (
  • 1:11 Skip to 1 minute and 11 seconds Although there are many different changes to the genetic architecture which drive variation, the commonest type of genetic variation is what we call a single nucleotide polymorphism, or a SNP. (
  • Behavioral genetic methodologies from twin and adoption studies through DNA analysis will be described and applied to address longstanding questions about the origins of individual differences in behavioral traits. (
  • We review past research, that has mainly studied single migratory traits in captive birds, and discuss how this work could be extended to study genetic variation in the wild and to account for genetic correlations and correlated selection. (
  • We advocate making more use of repeated measurements on single individuals to study the causes of among-individual variation in the wild, as they are easier to obtain than data on relatives and can provide valuable information for identifying and selecting traits. (
  • We propose extending this research agenda by using optimality models to predict levels of variation and covariation among traits and constraints. (
  • This may help us to select traits in which we might expect genetic variation, and to identify the most informative environmental axes. (
  • Exploring the molecular-genetic background of expression variation for porcine ADRB2 will provide insight into the mechanisms driving its regulatory divergence and may also contribute to unraveling the genetic basis of muscle-related traits in pigs. (
  • This study highlights the challenges of finding causal genetic variants underlying complex traits. (
  • We uncovered a vast amount of hidden genetic variation during our analyses, much of which affects important traits within the common fruit fly, D. melanogaster. (
  • Synthesis of the two dominant perspectives will require recognition that adaptation, divergence, drift and stability all depend on similar underlying quantitative genetic processes-processes that cannot be fully observed in continuously varying visible traits. (
  • The program supports many studies developing data analysis methods for how to relate variation to traits, diseases, and responses to drugs and environmental factors, such as association and admixture approaches, and how to use patterns of variation to infer demographic history, selection, and other population genetic processes. (
  • Nine important agronomic traits were used to assess the genetic diversity of Tunisian tall fescue and to investigate the extent of genotype X environment (GE) interaction and its implications for breeding programs. (
  • The objective of this study was to assess the genetic variation and the agronomic performance of a set of Tunisian tall fescue ecotypes and analyse the influence of pedoclimatic factors on agronomic traits. (
  • In 2007, researchers were dazzled by the degree to which genomes differ from one human to another and began to understand the role of these variations in disease and personal traits. (
  • Among-population genetic differentiation in scape length and flowering time was stronger than that of neutral marker loci, which is consistent with divergent selection acting on these traits. (
  • This variation can be seen as quantitative differences for nearly every phenotype, and artificial selection experiments in experimental organisms demonstrate that variation for most traits is heritable. (
  • Although the phenotypic effects of genetic variation are most evident in humans, because of the relative intensity with which human phenotypic richness has been investigated and characterized, investigators studying quantitative traits in humans have exhorted caution in extending techniques such as linkage disequilibrium mapping, that have been used to identify rare alleles with major effects inherited in Mendelian fashion, to the analysis of complex traits ( 5 , 11 , 16 ). (
  • Sufficient genetic diversity makes it more likely that favorable traits will emerge and proliferate as the fittest specimens populate subsequent generations. (
  • The focus of my research explores to what extent variation in quantitative life-history traits, e.g. litter size, individual birth size, metabolic rate, testosterone level and immuno-response, is evident at the genetic level. (
  • OBJECTIVE Genome-wide association studies that compare the statistical association between thousands of DNA variations and a human trait have detected 958 loci across 127 different diseases and traits. (
  • Traditionally, plant breeding has focused on nuclear-encoded crop traits and has hardly assessed variation in the cytoplasmic contribution to traits, or the interactions between nuclear genome and cytoplasmic genomes (the so-called cyto-nuclear interactions). (
  • Genetic component analysis showed that both genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PVC) were high for all the traits except bark thickness. (
  • Even monozygotic twins (who develop from one zygote) have infrequent genetic differences due to mutations occurring during development and gene copy-number variation . (
  • [1] Differences between individuals, even closely related individuals, are the key to techniques such as genetic fingerprinting . (
  • The amount of variation within a population refers to the differences that exist between the members of that population. (
  • There is potential to distinguish between adaptation from standing variation and that from new mutations by differences in the genomic signature of selection. (
  • By mapping differences in transcription factor binding among individuals, here we present the genetic basis of such variation on a genome-wide scale. (
  • in, in, in talking about genetic differences. (
  • Known gender differences in plasma ghrelin levels prompted us to investigate genetic variation of the ghrelin signaling system in females with severe alcohol dependence (n = 113) and in a selected control sample of female low-consumers of alcohol from a large cohort study in southwest Sweden (n = 212). (
  • Genetic variation will result in phenotypic variation if variation in the order of nucleotides in the DNA sequence results in a difference in the order of amino acids in proteins coded by that DNA sequence, and if the resultant differences in amino acid sequence influence the shape, and thus the function of the enzyme. (
  • European scientists, led by researchers from the University of Geneva (UNIGE)'s Faculty of Medicine in the context of the GEUVADIS project, today present a map that points to the genetic causes of differences between people. (
  • Knowing which genetic variants are responsible for differences in gene activity among individuals can give powerful clues for diagnosis, prognosis and intervention of different diseases. (
  • For the first time in animals, we have assembled a high-quality genome, permitting the discovery of all the genetic differences between two individuals within a species," said Mahul Chakraborty, a postdoctoral scholar in the Emerson laboratory and first author on the study. (
  • Researchers have discovered five inherited genetic differences that can increase the risk of men developing an aggressive form of prostate cancer. (
  • At some point the authors reveal the following: "Both language and geography explained a significant proportion of the genetic variance, but differences exist between and within the language families (table S5 and fig. S33, A to C) (4). (
  • Differences in the sequence of DNA among individuals are called genetic variation. (
  • Genetic variation explains some of the differences among people, such as eye color and blood group, as well as whether a person has a higher or lower risk for getting particular diseases. (
  • The program also works with other programs to support experimental and analysis development studies and databases relating variation to differences in gene function and regulation and to clinical effects. (
  • The 278-page work garnered widespread criticism, much of it from scientists, for suggesting that genetic differences (rather than culture) explain, for instance, why Western governments are more stable than those in African countries. (
  • Wade juxtaposes an incomplete and inaccurate explanation of our research on human genetic differences with speculation that recent natural selection has led to worldwide differences in I.Q. test results, political institutions and economic development. (
  • Genetic differences drive adaptive evolution of organisms to changes in environmental conditions. (
  • Genetic variation is a term used to describe the differences in the DNA sequence in each of our genomes. (
  • We also found certain differences with Mocoví, possibly due to a higher genetic flow of the latter with nonnatives. (
  • In clinical practice, inter-individual variations in response to sitagliptin and metformin treatment are commonly found, which may reflect inter-patient differences in disposition of these medications. (
  • Variations in glucosinolate content among genotypes suggest differences in their health-promoting properties and the opportunity for enhancement of their levels through breeding or genetic modification. (
  • These genetic differences mean the cancer may be particularly susceptible or resistant to a given treatment. (
  • Under these conditions, we found significant differences between the strains on behaviors indexing impulsive choice and on independent measures of locomotor activity, which subsequent heritability analysis showed could be related, in part, to genetic effects. (
  • we demonstrate that variation in genetic background arising from allelic polymorphisms can contribute to differences in this form of impulsive behavior. (
  • A second important process is genetic drift , which is the effect of random changes in the gene pool, under conditions where most mutations are neutral (that is, they do not appear to have any positive or negative selective effect on the organism). (
  • [ citation needed ] The second main cause of genetic variation is due to the high degree of neutrality of most mutations . (
  • Compared with new mutations, adaptation from standing genetic variation is likely to lead to faster evolution, the fixation of more alleles of small effect and the spread of more recessive alleles. (
  • Three primary sources of genetic variation: Mutations, Gene flow, Sex (genetic shuffling). (
  • Using this method, we believe we have added an important tool to our arsenal of SNP-to-gene assignment methods, allowing us to pinpoint disease-driving genetic mutations that have previously been difficult to properly assign risk,' said Hakon Hakonarson, MD, PhD, Director of the Center for Applied Genomics at CHOP and senior author of the paper. (
  • Mutations are the ultimate sources of genetic variation, but other mechanisms such as sexual reproduction and genetic drift contribute to it as well. (
  • Random mutations are the ultimate source of genetic variation. (
  • Genetic variation will only slowly be restored through the accumulation of mutations over many generations. (
  • Lifespan extension induced by genetic mutations has been shown in recent studies not to necessarily delay age-related behavioral decline, suggesting that longevity and behavioral aging may be two dissociable processes. (
  • Association studies provide genome-wide information about the genetic basis of complex disease, but medical research has focused primarily on protein-coding variants, owing to the difficulty of interpreting noncoding mutations. (
  • Analysis of double mutations in inbred experimental organisms suggests some principles for gene interaction that may apply to natural variation as well. (
  • Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size). (
  • The original sources of genetic variation are mutations, which are changes in the nucleotide sequence of DNA. (
  • Mutations create new alleles and increase genetic variability. (
  • This paper in Cell (open access) analyzed over 64,000 people ( data from the Exome Aggregation Consortium) for the sorts of variants most likely to make themselves felt: mis-sense and loss-of-function mutations (frameshift, stop codons, etc.) as well as copy number variation. (
  • Scientists then correlated patients' level of illness against various genetic mutations and found that variants of a gene known as TGFb1 were associated with worse disease. (
  • On a typical single locus (on some loci, such as SLC24A5 , most of the variation is between groups). (
  • We identified extensive Ste12-binding variation among individuals, and mapped underlying cis - and trans -acting loci responsible for such variation. (
  • Mathematica workbook for computing epistatic variances and the complete (A,D, AxA, AxD, DxD) genetic decomposition for two diallelic loci, as detailed on pages 85-92 and (especially) Example 2. (
  • Genetic variation within a population is commonly measured as the percentage of polymorphic gene loci or the percentage of gene loci in heterozygous individuals. (
  • Three previously known genetic links were confirmed and seven novel loci were identified by studying the entire genome in this progressive incurable disease. (
  • Many factors will make achieving this goal difficult ( 9 , 10 ), including the large number of polymorphisms, the possibility that many polymorphisms contribute small effects to a single phenotype, unrecognized population admixture ( 11 ), and the fact that phenotypic expression of variant alleles might be influenced differentially by environment ( 12 ), stochastic events ( 13 , 14 ), and interactions with multiple other genetic loci. (
  • Only one of these loci has been associated with glaucoma, and despite its clear role as a biomarker for the disease, Mendelian randomisation does not support inner retinal thickness being on the same genetic causal pathway as glaucoma. (
  • Yet these associations, like many successful genetic linkage analysis studies that predate them ( 2 ), only identify a genetic region or loci and do not directly locate the causative variant(s). (
  • Here, we review how our evolutionary understanding of migration may benefit from taking a quantitative-genetic approach and present a framework for studying the causes of phenotypic variation. (
  • The genetic component of human phenotypic variation is of great interest because of its impact on the quality of human life even though much of it may have little consequence for fitness ( 5 ). (
  • In these cybrids we investigate both the physiological consequences of the cyto-nuclear interactions, which affect plant performance, such as photosynthesis efficiency and growth, as well as the causal genetic factors underlying the observed phenotypic variation. (
  • Although being overweight is the major risk factor for developing diabetes, it is now becoming clear that an individual's genetic makeup has a big impact on whether or not they are going to develop diabetes," Professor Steve Humphries, lead researcher on the study from the University College London Centre for Cardiovascular Genetics told the BBC. (
  • Scientists have identified a genetic variation in people with type 2 diabetes that affects how the body's muscle cells respond to the hormone insulin, in a new study published today in Nature Genetics . (
  • Evolutionary developmental genetics has traditionally been conducted by two groups: Molecular evolutionists who emphasize divergence between species or higher taxa, and quantitative geneticists who study variation within species. (
  • The National Human Genome Research Institute (NHGRI) convened a workshop of scientists in the fields of genomic sequencing, sequencing technology development, population genetics, and ELSI research to discuss a number of issues associated with the idea of resequencing the human genome of many additional people for the purpose of further characterizing human genetic variation. (
  • The first portion of the book summarizes recent research in human population genetics, to support the author's argument that geographically defined 'races' are supported by patterns of genetic variation, and that the different environments encountered by these groups led to genetic adaptations after humans left Africa more than 50,000 years ago - such as lighter skin or the ability to digest milk sugar (lactose) into adulthood. (
  • A typical thesis project will contain both a genetic analytical and a molecular genetics component, although the size of each of these may vary according to the state of the research and the student's interests. (
  • David Altshuler, assistant professor of genetics and of medicine at Harvard Medical School, and co-chair with Donnelly and one other of the data analysis group on the HapMap project, said: 'He is one of the clear world leaders in the field of using mathematical and computational methods to analyse DNA variation data. (
  • An exploration of the genetics of earlobe attachment is just the latest collaborative research project to come out of the personal genetic testing company. (
  • The genetic factors responsible for inter-individual metabolic variability remain poorly understood. (
  • In order to explore this question, researchers from Dr. CAI Shiqing's lab studied the genetic origin of variability in the rate of aging using Caenorhabditis elegans as an animal model. (
  • Genetic variation may refer to Genetic diversity Genetic variability Genetic variance Genetic variation Genetic variant (disambiguation) This disambiguation page lists articles associated with the title Genetic variation. (
  • They evaluated whether they could be attributable to any of hundreds of thousands of sites of common variability in the genetic code across chromosomes. (
  • 454 Life Sciences, a Roche company, in collaboration with Yale University researchers today announced that they have developed a method, using the company's Genome Sequencer FLX system, to identify significant human genetic variability with an unprecedented level of detail. (
  • Although somatically acquired genomic alterations have long been recognized as the hallmarks of acute lymphoblastic leukemia (ALL), the last decade has shown that inherited genetic variations (germline) are important determinants of inter-patient variability in ALL susceptibility, drug response, and toxicities of ALL therapy. (
  • Gum yield and some morphological data were collect in three years to estimate mean effects, genetic variability, heritability and genetic advance in Acacia senegal provenances. (
  • This study indicated that there was sufficient genetic variability in Acacia senegal provenances that could be used as a base for improvement of yield and other component attributes of this species through direct selection and hybridization. (
  • Johnson, H.W., Robinson, H.F. and Comstock, R.E. (1955) Estimates of Genetic and Environmental Variability in Soya Bean. (
  • Nechif, O.R., Filimon, R.B. and Szilagyi, L. (2011) Genetic Variability, Heritability and Expected Genetic Advance as Indices for Yield and Yield Components Selection in Common Bean (Phaseolus vulgaris L.). Scientific Papers, UASVM Bucharest, Series A, 1222-5339. (
  • Alteration in melatonin signaling has been reported in a broad range of diseases, but little is known about the genetic variability of this pathway in humans. (
  • Adults with a genetic variation enabling them to express higher levels of fetal hemoglobin may have a reduced risk of Alzheimer's disease, researchers say. (
  • A study of 209 families with at least two siblings with Alzheimer's and one unaffected sibling showed that those with this genetic variation are less likely to have the disease, researchers say in Neurobiology of Aging. (
  • Researchers at Children's Hospital of Philadelphia (CHOP) have pinpointed a genetic variation responsible for driving the development of inflammatory bowel disease (IBD). (
  • Newswise - Researchers from The Cancer Institute of New Jersey (CINJ) are converging on Washington, D.C., this week for the 101st Annual Meeting of the American Association for Cancer Research (AACR) to share their findings on how a common genetic variation can impact diagnosis of breast cancer in postmenopausal women. (
  • A common genetic variation may be more significant than obesity as an indicator that a person is at risk of developing type 2 diabetes, according to a team of UK researchers. (
  • According to the researchers, the fact that so much variation escaped notice in D. melanogaster - a species with relatively simple genomes less like to hide variation - suggests that our own genomes, and those of the species we eat, are harboring an even larger store of medically and agriculturally important genetic variation. (
  • Now, a new study carried out by researchers from Dr. CAI Shiqing's lab at the Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology of the Chinese Academy of Sciences has uncovered a genetic basis for natural variation in aging rates. (
  • The researchers found that genetic variations in a novel neuropeptide coding gene (rgba-1) and its receptor gene npr-28 regulate the aging rate of worm behavior among wild isolates. (
  • The researchers then studied these variations in 4,977 French individuals. (
  • Australian researchers looking for a genetic lifeline to endangered hog deer species endemic to Pakistan, northern India and mainland southeast Asia have found widespread hybridization of the species in Victoria. (
  • MacArthur and colleagues pooled exome data contributed by researchers from more than two dozen disease-specific projects, creating a list of more than 7.4 million genetic variants from 60,706 individuals-10-fold larger than any prior exome database. (
  • These variations were key to a dozen research projects in 2007 called genome-wide association studies in which researchers compared the DNA of thousands of individuals with and without a disease to determine which small genetic variants pose risks. (
  • The researchers looked for similarities in genetic variations among thousands of people with each illness and compared them to controls, figuring out how much each pair of disorders is linked to the same genetic variants. (
  • Convinced that the presence of some genetic similarities confirm a common ancestry for these two kinds of snails, the researchers sought a transitional form and believe they found it in one genus of the Janthinidae family: the Recluzia. (
  • The new method enables researchers to analyze genome-wide structural variations (SV), the gross changes to the genetic code in a very fast and economic way. (
  • Researchers at the University of Michigan and the Mayo Clinic say that the flagship breast cancer drug, tamoxifen might not be very effective in women who inherit a common genetic variation. (
  • Researchers are now finding particular genetic variations in some of these non-coding regulatory regions, called enhancers, determine whether or not proteins are expressed in specific cell types in the brain and may play a role in a person's risk of developing psychiatric or neurological conditions. (
  • Beyond identifying genetic risk variants, the researchers validated their findings using pluripotent human stem cells. (
  • Researchers say their findings will help inform future studies investigating genetic risk variants in many different neurological conditions. (
  • Researchers from Uppsala University and others have for the first time determined the full genetic consequences of intense inbreeding in a threatened species. (
  • For medicine, study of human genetic variation may be important because some disease-causing alleles occur more often in people from specific geographic regions. (
  • These alternative sources of beneficial alleles can result in different evolutionary dynamics and distinct genetic outcomes. (
  • Crossing over (genetic recombination) and random segregation during meiosis can result in the production of new alleles or new combinations of alleles. (
  • Questions regarding the usefulness of the concept of "race" to the study of human genetic diversity must ultimately be answered with reference to the degree and patterning of genetic variation. (
  • When apportioning diversity, the amount of within-group variation plus the amount of among-group variation adds up to 100 percent. (
  • Genetic diversity of isolates of Glomus mosseae from different geographic areas detected by vegetative compatibility testing and biochemical and molecular analysis. (
  • Overall, these studies identified genetic regulators of molecular diversity among individuals and provide new insights into mechanisms of gene regulation. (
  • The two ways wherein meiosis increases genetic diversity in a species are crossing over and independent assortment of homologous chromosomes. (
  • The moral is that there are many ways that nature reduces genetic diversity, from random genetic drift to persistent directional selection, but migration is one way that intrapopulational diversity can increase. (
  • Therefore, a survey of the genetic diversity in Tunisian tall fescue is necessary to encourage rational management and selection programs involving the local tall fescue germplasm. (
  • Many reviews described natural genetic diversity in nature (e.g. (
  • 2007). The following review will briefly summarize past conclusions on the nature of molecular markers including SSR, but then focuses on SNP polymorphisms at global, regional, and local scales, and other sources of variation in nature in an attempt to summarize the current understanding of genetic diversity in diverse taxa across phylogeny, and outlines future prospects. (
  • Bioinformatics analyzed allozyme and DNA diversity at both coding and noncoding genomic regions permitting precise gene homologous alignment across taxa, the unraveling of gene and genome structure, expression, function, regulation, evolution, and the potential determination of the genetic basis of speciation and adaptation. (
  • Our study demonstrates that a large number of SVs are present in the human population and that SV plays a greater role in genetic diversity than SNP," explained Michael Snyder, PhD., senior author and Lewis B. Cullman Professor of Molecular, Cellular and Developmental Biology and Professor of Molecular Biophysics and Biochemistry and Director of the Yale Center for Genomics and Proteomics. (
  • On Öland, fluctuations in population size were more pronounced on thin than on deep soils, but genetic diversity was not related to soil depth. (
  • Sample of the genetic diversity within potatoes. (
  • The six crops shown in Photo 2 are all the same plant, just taken in a different direction utilizing the natural genetic diversity present within wild mustard. (
  • Probably the best example of all in how humans have manipulated and utilized naturally existing genetic diversity is in our best friends, dogs. (
  • The study of human genetic variation has evolutionary significance and medical applications. (
  • Resource that describes how genetic variation drives some of the basic mechanisms of evolutionary change. (
  • Evolutionary change results from selection acting on genetic variation. (
  • Evolutionary theory suggests that, for the long-term survival of a species, we need to conserve not just individual members of a species, but also a species' ability to evolve in the face of changing environmental variables which means conserving individuals and genetic variation. (
  • The risk of extinction or population decline because of low genetic variation is predicted by evolutionary theory. (
  • In short, the rate of evolutionary change is proportional to the genotypic variation that selection has to work with. (
  • They are basing all of their evolutionary conclusions on the assumption that some genetic similarity confirms common ancestry of two families of dissimilar marine molluscs. (
  • Likewise, questions concerning which evolutionary processes influence natural genetic variation for phenotypic, quantitative-trait (QTL) variation (Mitchell-Olds et al. (
  • This article, "Genetic variation in nature" addresses a fundamental question in evolutionary biology : What is genetic variation, how large it is and what is its significance in nature. (
  • In humans, the main cause [ citation needed ] is genetic drift . (
  • Genetic variation among humans occurs on many scales, from gross alterations in the human karyotype to single nucleotide changes. (
  • The study, entitled "Paired-End Mapping Reveals Extensive Genomic Structural Variation in Humans," appears online (ahead of print) today in the journal Science. (
  • Humans have unexpectedly high genetic variation in the receptor for a key pregnancy-maintaining hormone, according to research led by scientists at the Stanford University School of Medicine . (
  • To determine the impact of the genetic mutation on Alzheimer's risk, studies need to be done on more Alzheimer's patients and their families, including taking blood levels of fetal hemoglobin, says Dr. Rodney T. Perry, UAB molecular geneticist and a study corresponding author. (
  • resulting from genetic mutation caused by radiation or by chemical damage. (
  • Mutation in either TSC1 or a companion gene known as TSC2, a relatively rare occurrence, is known to cause non-cancerous growths in multiple vital organs - a genetic condition known as tuberous sclerosis. (
  • There are multiple sources of genetic variation, including mutation and genetic recombination. (
  • A high mutation rate caused by the lack of a proofreading mechanism appears to be a major source of the genetic variation that contributes to RNA virus evolution. (
  • Secondly, his lab has pioneered models to extract information about the underlying biology of variation and mutation and about the history of mankind. (
  • Among these variations, we found a splice site mutation in ASMT (IVS5+2T>C) and one stop mutation in MTNR1A (Y170X) - detected exclusively in patients with ADHD - for which biochemical analyses indicated that they abolish the activity of ASMT and MTNR1A. (
  • Figure 4: Distribution of rDNA variation among individual nuclei in two Glomus species. (
  • As an endangered species dwindles, it loses genetic variation and even if the species rebounds, its level of genetic variation will not. (
  • For this reason, an endangered species with low genetic variation may risk extinction long after its population size has recovered. (
  • Similar epidemics could sweep through other vulnerable species with low genetic variation, increasing their chance of extinction. (
  • With this unique resource in hand, we have already characterized several candidate structural variation which show evidence for phenotypic adaptation, which can function to drive species evolution," said Emerson. (
  • As part of an interdisciplinary project between the groups of Christian Hardtke ( ) and Giorgina Bernasconi ( ), a postdoctoral position is available to study natural genetic variation in root morphology in the model plant species Arabidopsis thaliana. (
  • Genetic variation is abundant in all natural species, and most is expected to be neutral or nearly neutral with respect to fitness ( 3 ). (
  • For instance, we know that genetic variation contributes to the evolution of species. (
  • We showed that most transcription factor binding variation is cis -linked, and that many variations are associated with polymorphisms residing in the binding motifs of Ste12 as well as those of several proposed Ste12 cofactors. (
  • Natural selection can also maintain genetic variation in balanced polymorphisms. (
  • At present, the largest data set on human variation is being generated by the International HapMap Project [], which is genotyping a few million single nucleotide polymorphisms on 270 individuals from four geographically separated sites from around the world. (
  • The variations in the progesterone receptor gene - consisting of single nucleotide polymorphisms, or one-letter changes in the genetic code - were found in regions of the gene that regulate when it is switched on and off. (
  • Previous studies of human genomic variation tended to look at changes called single nucleotide polymorphism, variations that involve just one nucleotide, commonly referred to as SNP. (
  • The program also seeks to relate there genetic variants to functional variation and phenotype. (
  • What we do know from the Bible is that God made each kind of organism fully functional and capable of coping with different environments through genetic variations. (
  • The aim of this research is to use novel genetic resources, in the form of chromosome substitution libraries (CSLs), and new, genome-wide, epistatic analysis software to reveal functional genetic variation that is otherwise undetectable in conventional mapping approaches. (
  • Sitagliptin and metformin are known as substrates of some transporters (P-gp, OAT3, OCT1 and OCT2) and some functional variations of these transporters were reported. (
  • Looking at the mutant forms that were predicted to have changes in functional regions, they showed that some of them have less effective signaling across the board (agonists, partial agonists, and antagonists alike), but others showed real variations between the different classes. (
  • Alternatively, the observed associated variant may be directly functional, working to modulate transcriptional elements operating at large genetic distances. (
  • These genetic and functional results represent the first comprehensive ascertainment of melatonin signaling deficiency in ADHD. (
  • The regional geographic axes of greatest phonemic differentiation correspond to axes of genetic differentiation, suggesting that there is a relationship between human dispersal and linguistic variation. (
  • It also performs tests for Hardy-Weinberg equilibrium, exact tests for genetic differentiation, Mantel tests, and UPGMA cluster analyses. (
  • Alatalo RV, Gustafsson L (1988) Genetic component of morphological differentiation in Coal Tits under competitive release. (
  • Developing statistical methods to relate genetic variation to phenotypes, disease, and function. (
  • The idea of the neutrality theory of molecular evolution (Kimura, 1983) in which nature is sharply dichotomized into phenotypes subjected to positive Darwinian selection and genotypes that are largely invisible to natural selection and governed primarily by random genetic drift (Kimura 1983) is unrealistic. (
  • Genetic variation affects morphological retinal phenotypes extracted from UK Biobank optical coherence tomography images. (
  • A study identifies genetic variants that are linked to multiple phenotypes. (
  • Genetic analysis of genome-wide variation in human gene expression. (
  • We report that genetic variation at this locus does not influence FTO gene expression levels ( P = 0.38), but is strongly correlated with expression of RBL2 ( P = 2.7 × 10 −5 ), ∼270,000 base pairs distant to FTO . (
  • CONCLUSIONS These data suggest that variants at FTO influence RBL2 gene expression at large genetic distances. (
  • The team, led by Monkol Lek , a research fellow in the MacArthur lab, found variants spaced around every eight base pairs, on average, within regions of the genome that are particularly prone to variation. (
  • Several of these "hot spots" are regions of the genome known to correlate to some genetic diseases such as Velocardiofacial Syndrome, and Williams-Beuren Syndrome. (
  • Whole-exome sequencing of families affected by simplex autism has yielded tremendous insight into genetic variants conferring risk in coding regions of the genome. (
  • Genetic variation within noncoding and regulatory regions of the genome, however, remains largely unknown. (
  • Within a language family, phoneme evolution along genetic, geographic, or cognate-based linguistic trees predicts similar ancestral phoneme states to those predicted from ancient sources. (
  • More genetic sampling could further elucidate the relative roles of vertical and horizontal transmission in phoneme evolution. (
  • Welch, D. M. & Meselson, M. Evidence for the evolution of bdelloid rotifers without sexual reproduction or genetic exchange. (
  • Genetic recombination also has been shown to play a key role in generating the genetic variation that underlies RNA virus evolution. (
  • We offer cryptic genetic variation and conditional neutrality as mechanisms by which standing genetic variation can lead to developmental system drift and, sheltered within canalized processes, may facilitate developmental transitions and the evolution of novelty. (
  • Trade-offs in the sizes of visual and olfactory organs are a common feature of animal evolution, but the underlying genetic and developmental mechanisms have not been clear. (
  • Taken together, the results indicate that habitat connectivity and environmental heterogeneity contribute to high neutral and adaptive genetic variation in Primula farinosa on the island Öland, SE Sweden, and illustrate that effects on both male and female reproductive success need to be considered to understand fully the evolution of floral display. (
  • Overall, this survey on the bank vole genome will provide valuable insights into genetic architecture of the evolution of life-histories. (
  • Section "copy number variation": at the end , "Significant temporal fluctutations in the copy number of Tes provide new insight into genome evolution. (
  • This is caused by natural selection or genetic drift. (
  • A process of genetic drift seems to be enhanced by the social behavior of the Wichí, since they live apart from other native and nonnative groups. (
  • Genetic variation and recombination by transposable elements and endogenous retroviruses sometimes is supplemented by a variety of persistent viruses and their defectives which generate genetic novelty in host genomes. (
  • Numerical variation in whole chromosomes or genomes can be either polyploidy or aneuploidy. (
  • Numerous RNA viruses are capable of genetic recombination when at least two viral genomes are present in the same host cell. (
  • Looking at the genomes of more than 1,500 patients with idiopathic pulmonary fibrosis, a rare and devastating lung disease, a new study found multiple genetic associations with the disease. (
  • The Genetic Variation Program supports large-scale studies of human genetic variation as part of projects such as the International HapMap Project and the 1000 Genomes Project. (
  • An integrated map of genetic variation from 1,092 human genomes. (
  • The degree to which variation in the nuclear and cytoplasmic genomes influences this interaction is not well understood. (
  • In this latest research, blood samples from more than 1,000 women recruited through CINJ clinics were evaluated for the presence of genetic changes in the DNA sequence of the TSC1 gene. (
  • New technology now allows scientists to directly sequence DNA which has identified even more genetic variation than was previously detected by protein electrophoresis. (
  • Almost every living thing shares an identical genetic code, with three nucleic acids in an RNA sequence coding for a single amino acid in the translated protein sequence. (
  • 1 kb) can be either copy number variation (loss or gain), or chromosomal rearrangement (translocation, inversion, or Segmental acquired uniparental disomy). (
  • Furthermore, random fertilization also contributes to variation. (
  • Multiple similar inflammatory pathways are activated by both the downstream effects of the chromosome 9 variant and colchicine, potentially occluding the genetic effect in the group receiving the drug. (
  • And then, the, the term genetic variant is just kind of a generic term. (
  • Ph.D., one of the authors on this study, comments, "This first study, while requiring replication, identifies a very common genetic variant that appears to affect smoking cessation treatment outcome. (
  • While the dataset is not large enough to see every possible genetic variant, at these particular sites, the team was able to capture about 63 percent of all possible synonymous variants. (
  • The variations may have more impact on males because they have only one copy of this X-chromosomal gene, while females have two copies, one of which will be of the H variant in most cases. (
  • They also found that women who carry the genetic variant do not have intense hot flashes. (
  • Our study suggests that women who inherit a genetic variant in the CYP2D6 gene appear to be at higher risk of relapse when treated with five years of tamoxifen. (
  • Our study of the transmission of polymorphic genetic markers in natural isolates of Glomus etunicatum , coupled with direct amplification of rDNA from microdissected nuclei by polymerase chain reaction, supports the alternative hypothesis of homokaryosis, in which nuclei populating AM fungal individuals are genetically uniform. (
  • However, as each genetic region has multiple markers, it's important to identify those that are causally involved. (
  • However, genetic and biological markers are needed to determine whether patients will respond to them. (
  • Patients with four or all five of these genetic markers had a 50 per cent higher risk of dying from their prostate cancer than those with two or fewer. (
  • In the new research, scientists from international institutions including Imperial College London, McGill University, Canada, CNRS, France, and the University of Copenhagen, Denmark, looked for genetic markers in over 14,000 people and identified four variations associated with type 2 diabetes. (
  • The aim of this study was to assess the variation of X chromosome present in the Wichí population living around Misión Nueva Pompeya, in Chaco Province, and to identify particular variation of X-repetitive markers (short tandem repeats, X-STRs) in Chaco Amerindians. (
  • Although we found no new allele or undescribed variation, the whole pattern of variation for these markers gives the Wichí a particular population identity. (
  • In population genetic studies, the neutral genetic markers (microsatellites) are used to discover the putative molecular changes associated with the population density fluctuations. (
  • However, the genetic variation of X chromosome has not yet been fully analyzed. (
  • The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time. (
  • Worldwide patterns of genetic variation are driven by human demographic history. (
  • A polymorphism is a genetic difference that is common in the, in the population. (
  • Is the Subject Area "Genetic polymorphism" applicable to this article? (
  • Genetic polymorphism and heterozygosity in nature are structured nonrandomly on a massive scale. (
  • The same patients were asked to take part in an additional study to help identify genetic determinants in the COVID-19 outcome. (
  • Interestingly, 0.3% and 5.1% of the colchicine trial participants died or were hospitalized, respectively, while only 3.1% of those who went on to be included in the genetic study were hospitalized, with none dying. (
  • Unfortunately, as the authors state, healthy participant bias means that less healthy patients are less likely to participate in the additional genetic study. (
  • A new study being published in the September 15th issue of Biological Psychiatry reports that genetic variation in a particular enzyme affects the success rates of treatment with bupropion, an anti-smoking drug. (
  • In the future, reaction-norm approaches may become very important, as they allow the study of genetic and environmental effects on phenotypic expression within a single framework, as well as of their interactions. (
  • A case study of the cheetah, which has famously low genetic variation, suggests the sorts of dangers that are possible. (
  • Multiple genetic variations that should help with future efforts to treat pulmonary fibrosis was discovered by a newly published study. (
  • This new study found evidence that common genetic variation is an important contributor to the risk of developing IPF, accounting for approximately one-third of the risk of developing disease. (
  • This study reveals the first genetic pathway underlying natural variation in the rate of aging, and uncovers the important role of neuropeptide-mediated glia-neuron signaling in controlling the aging rate. (
  • Today's study shows for the first time a genetic variation that seems to impair the ability of the body's muscle cells to use insulin to help them make energy. (
  • Professor Philippe Froguel, one of the corresponding authors of today's study from the Department of Genomic Medicine at Imperial College London, said: "We are very excited about these results - this is the first genetic evidence that a defect in the way insulin works in muscles can contribute to diabetes. (
  • Five major mental illnesses - depression , bipolar disorder, ADHD , schizophrenia and autism - are traceable to the same inherited genetic variations, according to the largest genome-wide study of its kind. (
  • Since our study only looked at common gene variants, the total genetic overlap between the disorders is likely higher," said Naomi Wray, Ph.D., University of Queensland, Brisbane, Australia. (
  • The novel approach described today in Science, called Paired End Mapping (PEM), used 454 Sequencing to comprehensively study SV at an unmatched level of resolution, detecting most of the structural variation in the human genome. (
  • This highly accurate study of human genomic structural variation along with the recently sequenced genome of Jim Watson confirms that 454 Sequencing is the first affordable technology to offer a comprehensive view of the human genome. (
  • But according to a new study published in JAMA , this effect may depend on certain genetic variations an individual possesses. (
  • In an editorial linked to the study, Dr. Richard C. Wender, of the American Cancer Society, says the findings from Dr. Chan and colleagues may bring us a step closer to "affordably and efficiently" conducting genetic testing in order to reduce disease risk in healthy individuals. (
  • This study is especially important in the field of genetic modifiers, because we had enough patients -- over 1,300 -- and a robust study design to assure that our observation is likely correct," Knowles said. (
  • In the present study, we exploited the isogenic nature of inbred mice, in combination with a tractable mouse model of delayed reinforcement, to look for evidence of genetic effects on impulsivity. (
  • Patients who undergo genetic testing for inherited heart disease need to be better informed to know how to interpret the results and understand the impact the results will have on their life, a University of Sydney study has found. (
  • The affects of structural variation on agonist/antagonist pharmacology (i.e. the u-opioid data in the paper) makes perfect sense from the perspective of GPCR theory. (
  • We describe the distribution of genetic variation across the global sample, and discuss the implications for common disease studies. (
  • The time to symptom remission following onset was recorded amongst the genetic analysis group, and in-silico methods were utilized to identify two common genetic variations correlated with shorter disease period. (
  • Since symptom duration is a strong predictor of disease severity this newly discovered genetic risk factor could aid in predicting outcome. (
  • The two main forms of IBD, Crohn's disease and ulcerative colitis, have an important genetic component. (
  • But if they do not exist if the right genetic variation is not present the population will not evolve and could be wiped out by the disease. (
  • Although this example is by no means conclusive, it is possible that the cheetahs' low genetic variation unlike the lions' more extensive variation meant that none of them had the right immune system gene variants to fend off the disease. (
  • The GEUVADIS (Genetic European Variation in health and Disease) project, funded by the European Commission's FP7 programme, is led by Professor Xavier Estivill of the Center of Genomic Regulation (CRG) in Barcelona. (
  • A key next step for research is figuring out how these genetic variants work with environmental factors in the development of the disease. (
  • These findings also offer new insights into the genetic causes of prostate cancer - the more we learn about how the disease develops, the greater chance we have of identifying people at risk and finding new treatments. (
  • Non-coding enhancer DNA may be important for identifying genetic risk in neurological disease. (
  • Focusing on genetic variation associated with Alzheimer's disease (AD), we show preferential enrichment in disease risk variants in enhancers that are selectively active in microglia, the major immune cell in the brain," said senior author Christopher Glass, MD, PhD, professor of cellular and molecular medicine and professor of medicine at UC San Diego School of Medicine. (
  • First, the defining of causative risk predisposing genetic variation will allow improvements to be made to current clinical risk models for disease onset and progression. (
  • Second, knowledge of the gene's identity that mediates the biological consequences of this variation will improve understanding of the molecular pathways that participate in disease pathogenic processes. (
  • This GRS will be held in conjunction with the "Human Genetic Variation and Disease" Gordon Research Conference (GRC). (
  • In 2007, we saw many publications in very prestigious journals that used genome-wide association studies (GWAS) to identify common genetic factors that influence health and disease, and I think that's where the AAAS felt motivated to call human genetic variation the breakthrough of the year. (
  • Handled with care, the new "HapMap" of genetic variation could reveal the genetic roots of many diseases. (
  • Second, it involves understanding how, with such information, it becomes possible to undertake systematic studies of the genetic factors underlying inherited susceptibility to common diseases. (
  • In addition to expanding the library of genetic changes that can underlie pulmonary fibrosis, this study's findings demonstrate that both rare and common genetic variants contribute significantly to pulmonary fibrosis risk," says James Kiley, PhD, Director of NHLBI's Division of Lung Diseases. (
  • Among its strengths, they said, were its large size -- which is essential for such studies if they are to be useful -- that it focused on a single class of gene variation and that it took into account numerous possible confounders such as sex, other illnesses like asthmas, enrollment sites, associated diseases and infections. (
  • An international team of scientists and doctors has identified a family of five new genetic diseases which are likely to affect more than 1 in 5000 children. (
  • Philip W. Hedrick , Rhonda N. Lee , and Colleen Buchanan "Canine Parvovirus Enteritis, Canine Distemper, and Major Histocompatibility Complex Genetic Variation in Mexican Wolves," Journal of Wildlife Diseases 39(4), 909-913, (1 October 2003). (
  • 2007) or what the genetic basis of ecologically important morphological variation such as diverse color patterns of mammals (Steiner et al. (
  • Genetic variation can be divided into different forms according to the size and type of genomic variation underpinning genetic change. (
  • By using a variety of genetic tools, this research will characterize the molecular aspect of adaptive genetic variation in the bank vole. (
  • Crossing over creates genetic variation by exchanging DNA between two nonsister chromatids to produce genetically unique chromosomes. (
  • These gametes contain 23 chromosomes, which is half of the genetic information of the parent. (
  • Bever, J. D. & Morton, J. Heritable variation and mechanisms of inheritance of spore shape within a population of Scutellospora pellucida , an arbuscular mycorrhizal fungus. (
  • Despite the great advance in genetic control of animal lifespan, little was known about the regulatory mechanisms of healthy aging, i.e., aging with limited loss of physiological function. (
  • In particular, unbiased genome-wide association studies (GWAS) have identified germline variants strongly associated with the predisposition to ALL in children, providing novel insights into the mechanisms of leukemogenesis and evidence for complex interactions between inherited and acquired genetic variations in ALL. (
  • A website highlights common genetic variations that made a splash in 2009. (
  • Understanding the pattern of common genetic variation in the human population is a major focus of the program. (
  • First, this involves creating a systematic catalog of the full range of genetic variants (large and small, rare and common) present in the human population, through the analysis of DNA sequencing data from hundreds of thousands of people. (
  • This research will provide the groundwork for understanding how common genetic changes in TSC1 may affect risk of developing breast and other cancers but may also provide clues for identifying those patients who may receive the most benefit from therapies targeting the mTOR pathway," noted Dr. Hirshfield. (
  • The overlap in heritability that could be attributed to common genetic variation was about 15 percent between schizophrenia and bipolar disorder, about 10 percent between bipolar disorder and depression, about 9 percent between schizophrenia and depression, and about 3 percent between schizophrenia and autism. (
  • For example, common genetic variation accounted for 23 percent of schizophrenia, but evidence from twin and family studies estimate its total heritability at 81 percent. (
  • A common Designer explains the presence of genetic similarity between different kinds of creatures. (
  • Looking across 108 GPCRs that are targeted by known drugs, the team found over 14,000 variants, and the distribution was long-tailed indeed: any individual receptor had an average of 3 or 4 common variations across the 64,000 patients (more than one in a thousand minor allele frequency ) and 128 rare ones. (
  • This was not attributable to mundane confounds related to individual task requirements but instead indicated the existence of common genetic factors influencing variation in both impulsivity and locomotor activity. (
  • Developing high-resolution maps of genetic variation and haplotypes. (
  • Database of human genetic variants associated with longevity. (
  • A Windows program (by Mark Miller at Northern Arizona University) for the analysis of allozyme and molecular population genetic data. (
  • A simple Mathematica program for generating color plots (as a function of allele frequency) of the total, additive and dominance genetic variances, heritability, breeding values, average effects and domiance deviations for a single diallelic locus. (
  • Until now, scientists had not been able to identify the genetic factors contributing to insulin resistance in type 2 diabetes. (
  • An international group of 253 scientists has conducted one of the largest genetic studies to date and identified 74 genetic variants that are associated with the years of formal education that an individual completes. (
  • Scientists at the CNIC have developed new methods to produce and analyze genetic mosaics. (
  • The primary goals were to assess the level of heritable variation in asymmetry, the effect of selfing on mean asymmetry, and the relationship between asymmetry and components of fitness. (
  • Adaptation from standing genetic variation. (
  • The genetic distance is then simply a function of time since divergence, as well as the magnitude of gene flow (which is inversely proportional to geographic distance). (
  • Going back to South Asians, putting them on a genetic-geographic map and attempting to adduce deep demographic history is total folly, because evidence is building that they are a compound synthetic population , whose origins in time are relatively recent. (
  • For population pairs from the same cluster, as geographic distance increases, genetic distance increases in a linear manner, consistent with a clinal population structure. (
  • However, for pairs from different clusters, genetic distance is generally larger than that between intracluster pairs that have the same geographic distance. (
  • For example, genetic distances for population pairs with one population in Eurasia and the other in East Asia are greater than those for pairs at equivalent geographic distance within Eurasia or within East Asia. (
  • Loosely speaking, it is these small discontinuous jumps in genetic distance-across oceans, the Himalayas, and the Sahara-that provide the basis for the ability of STRUCTURE to identify clusters that correspond to geographic regions. (
  • Students play an interactive game, Fitness Fever to learn the underlying genetic variation that natural selection acts upon. (
  • Despite great interest in studying natural variation in aging rates to identify factors that control healthy aging, no such factor had been found. (
  • Further studies on natural variation in the rate of aging will pave the way for a comprehensive understanding of the biological regulation of healthy aging. (
  • Genetic variation is important because it provides the "raw material" for natural selection. (
  • Protein and DNA variations are largely subjected to natural selection. (
  • Other receptors that show a lot of natural variation include CCKA, dopamine D5, the calcitonin receptor, and somatostatin SSR5. (
  • Is it natural genetic variation or genetic modification? (
  • The next time you see 2-inch long blackberries, quarter-size blueberries, thumb-size raspberries, strawberries as big as your fist and multicolored carrots or beets, that is just an expression of the natural genetic variation existing within that plant we are utilizing to improve nutritional components, flavor or make them more visibly appealing. (
  • The final sections include descriptions of genetic variation in model organisms and discussions of recent insights into human genetic ancestry, forensics, and human variation. (
  • Science recognized "Human Genetic Variation" as the 2007 Breakthrough of the Year, and detailed nine other of the year's most significant scientific accomplishments in its 21 December issue. (
  • The genetic pathway associated with this variation is involved in other immune disorders, suggesting the mechanism they identified could serve as an important therapeutic target. (
  • Genetic variations of the melatonin pathway in patients with attention-deficit and hyperactivity disorders. (
  • Linguistic data are often combined with genetic data to frame inferences about human population history. (
  • If, for example, a population consisted entirely of clones, then everyone in the population would be genetically the same, and there would be no variation within the population. (
  • The more different the individuals are from each other genetically, the greater the level of variation within the population. (
  • Without genetic variation, a population cannot evolve in response to changing environmental variables and, as a result, may face an increased risk of extinction. (
  • Genetic variation doesn't rebound from a decrease as quickly as population size. (
  • A paternal half-sibling analysis of data on flower asymmetry failed to detect significant levels of genetic variation at the within-population level, whereas the between-population component reached significance for all measures of asymmetry. (
  • Analysis of family-structured data from another crossing experiment revealed significant between-population variation in cotyledon asymmetry and a tendency for inbred progeny to produce more asymmetric cotyledons than outbred progeny. (
  • The expression of atopy and AHR is distinctly associated with genetic variations in VEGF, TGF-β1, and FGFR in the Korean population. (
  • Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. (
  • We already know that there's genetic variation in every population and in every individual. (