Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Recombination, Genetic: 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.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Lod Score: The total relative probability, expressed on a logarithmic scale, that a linkage relationship exists among selected loci. Lod is an acronym for "logarithmic odds."Pedigree: 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.Microsatellite Repeats: 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).Homologous Recombination: An exchange of DNA between matching or similar sequences.Linkage Disequilibrium: 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.Models, Genetic: 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.Crossing Over, Genetic: The reciprocal exchange of segments at corresponding positions along pairs of homologous CHROMOSOMES by symmetrical breakage and crosswise rejoining forming cross-over sites (HOLLIDAY JUNCTIONS) that are resolved during CHROMOSOME SEGREGATION. Crossing-over typically occurs during MEIOSIS but it may also occur in the absence of meiosis, for example, with bacterial chromosomes, organelle chromosomes, or somatic cell nuclear chromosomes.Molecular Sequence Data: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Crosses, Genetic: 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.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Mutation: 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.Gene Frequency: The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.Polymorphism, Restriction Fragment Length: 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.Polymorphism, Genetic: 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.Rad52 DNA Repair and Recombination Protein: A DNA-binding protein that mediates DNA REPAIR of double strand breaks, and HOMOLOGOUS RECOMBINATION.Meiosis: A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.Quantitative Trait Loci: Genetic loci associated with a QUANTITATIVE TRAIT.V(D)J Recombination: The process by which the V (variable), D (diversity), and J (joining) segments of IMMUNOGLOBULIN GENES or T-CELL RECEPTOR GENES are assembled during the development of LYMPHOID CELLS using NONHOMOLOGOUS DNA END-JOINING.Haplotypes: 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.Buxus: A plant genus of the family BUXACEAE. Members contain steroidal alkaloids.Genetic Variation: Genotypic differences observed among individuals in a population.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Physical Chromosome Mapping: Mapping of the linear order of genes on a chromosome with units indicating their distances by using methods other than genetic recombination. These methods include nucleotide sequencing, overlapping deletions in polytene chromosomes, and electron micrography of heteroduplex DNA. (From King & Stansfield, A Dictionary of Genetics, 5th ed)Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.DNA Repair: The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.Integrases: Recombinases that insert exogenous DNA into the host genome. Examples include proteins encoded by the POL GENE of RETROVIRIDAE and also by temperate BACTERIOPHAGES, the best known being BACTERIOPHAGE LAMBDA.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.DNA: 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).Chromosomes: 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)Gene Conversion: The asymmetrical segregation of genes during replication which leads to the production of non-reciprocal recombinant strands and the apparent conversion of one allele into another. Thus, e.g., the meiotic products of an Aa individual may be AAAa or aaaA instead of AAaa, i.e., the A allele has been converted into the a allele or vice versa.Rad51 Recombinase: A Rec A recombinase found in eukaryotes. Rad51 is involved in DNA REPAIR of double-strand breaks.Chromosomes, Artificial, Bacterial: DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.Genome: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Chromosomes, Human, Pair 2: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Synteny: The presence of two or more genetic loci on the same chromosome. Extensions of this original definition refer to the similarity in content and organization between chromosomes, of different species for example.Genetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Chromosomes, Human, Pair 1: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Recombinases: A broad category of enzymes that are involved in the process of GENETIC RECOMBINATION.Genetic Heterogeneity: 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)Polymerase Chain Reaction: 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.DNA Nucleotidyltransferases: Enzymes that catalyze the incorporation of deoxyribonucleotides into a chain of DNA. EC 2.7.7.-.X Chromosome: The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.Genetics, Population: 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.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Chromosomes, Fungal: Structures within the nucleus of fungal cells consisting of or containing DNA, which carry genetic information essential to the cell.Genes, Recessive: Genes that influence the PHENOTYPE only in the homozygous state.Expressed Sequence Tags: Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.VDJ Recombinases: Recombinases involved in the rearrangement of immunity-related GENES such as IMMUNOGLOBULIN GENES and T-CELL RECEPTOR GENES.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Quantitative Trait, Heritable: A characteristic showing quantitative inheritance such as SKIN PIGMENTATION in humans. (From A Dictionary of Genetics, 4th ed)Sequence Tagged Sites: Short tracts of DNA sequence that are used as landmarks in GENOME mapping. In most instances, 200 to 500 base pairs of sequence define a Sequence Tagged Site (STS) that is operationally unique in the human genome (i.e., can be specifically detected by the polymerase chain reaction in the presence of all other genomic sequences). The overwhelming advantage of STSs over mapping landmarks defined in other ways is that the means of testing for the presence of a particular STS can be completely described as information in a database.Amplified Fragment Length Polymorphism Analysis: 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.DNA Breaks, Double-Stranded: Interruptions in the sugar-phosphate backbone of DNA, across both strands adjacently.Amino Acid Sequence: 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.Genome, Human: 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.Repetitive Sequences, Nucleic Acid: Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).Chromosomes, Human, Pair 5: One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Dendrobium: A plant genus of the family ORCHIDACEAE that contains dihydroayapin (COUMARINS) and phenanthraquinones.Species Specificity: 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.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Genetic Loci: 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.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Hybridization, Genetic: The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Butylated Hydroxyanisole: Mixture of 2- and 3-tert-butyl-4-methoxyphenols that is used as an antioxidant in foods, cosmetics, and pharmaceuticals.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Chromosomes, Human, Pair 11: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Heterozygote Detection: Identification of genetic carriers for a given trait.Family Health: The health status of the family as a unit including the impact of the health of one member of the family on the family as a unit and on individual family members; also, the impact of family organization or disorganization on the health status of its members.DNA Primers: 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.Immunoglobulin Class Switching: Gene rearrangement of the B-lymphocyte which results in a substitution in the type of heavy-chain constant region that is expressed. This allows the effector response to change while the antigen binding specificity (variable region) remains the same. The majority of class switching occurs by a DNA recombination event but it also can take place at the level of RNA processing.Chromosomes, Human, Pair 10: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Chromosomes, Human: Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.Chromosomes, Human, Pair 3: A specific pair of human chromosomes in group A (CHROMOSOMES, HUMAN, 1-3) of the human chromosome classification.Likelihood Functions: 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.DNA, Fungal: Deoxyribonucleic acid that makes up the genetic material of fungi.Chromosomes, Human, Pair 4: A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.Chromosomes, Mammalian: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.Genes, Plant: The functional hereditary units of PLANTS.Chromosomes, Human, Pair 12: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Rec A Recombinases: A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.Chromosomes, Human, Pair 16: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Attachment Sites, Microbiological: Specific loci on both the bacterial DNA (attB) and the phage DNA (attP) which delineate the sites where recombination takes place between them, as the phage DNA becomes integrated (inserted) into the BACTERIAL DNA during LYSOGENY.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Chromosomes, Human, Pair 19: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.DNA Damage: Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Nuclear Family: A family composed of spouses and their children.DNA Helicases: Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate DNA strands.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Homozygote: An individual in which both alleles at a given locus are identical.Chromosome Pairing: The alignment of CHROMOSOMES at homologous sequences.Chromosomes, Human, Pair 6: A specific pair GROUP C CHROMSOMES of the human chromosome classification.Penetrance: The percent frequency with which a dominant or homozygous recessive gene or gene combination manifests itself in the phenotype of the carriers. (From Glossary of Genetics, 5th ed)Immunoglobulin Joining Region: A segment of the immunoglobulin heavy chains, encoded by the IMMUNOGLOBULIN HEAVY CHAIN GENES in the J segment where, during the maturation of B-LYMPHOCYTES; the gene segment for the variable region upstream is joined to a constant region gene segment downstream. The exact position of joining of the two gene segments is variable and contributes to ANTIBODY DIVERSITY. It is distinguished from the IMMUNOGLOBULIN J CHAINS; a separate polypeptide that serves as a linkage piece in polymeric IGA or IGM.Diploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.Genomics: The systematic study of the complete DNA sequences (GENOME) of organisms.Epistasis, Genetic: 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.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Chromosomes, Human, Pair 17: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Chromosomes, Human, Pair 7: A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.Exodeoxyribonucleases: A family of enzymes that catalyze the exonucleolytic cleavage of DNA. It includes members of the class EC 3.1.11 that produce 5'-phosphomonoesters as cleavage products.Catfishes: Common name of the order Siluriformes. This order contains many families and over 2,000 species, including venomous species. Heteropneustes and Plotosus genera have dangerous stings and are aggressive. Most species are passive stingers.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Sex Chromosomes: The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)Genes, RAG-1: Genes involved in activating the enzyme VDJ recombinase. RAG-1 is located on chromosome 11 in humans (chromosome 2 in mice) and is expressed exclusively in maturing lymphocytes.DNA Replication: The process by which a DNA molecule is duplicated.DNA Probes: Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.In Situ Hybridization, Fluorescence: A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.Multigene Family: 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)Gene Targeting: The integration of exogenous DNA into the genome of an organism at sites where its expression can be suitably controlled. This integration occurs as a result of homologous recombination.DNA, Satellite: Highly repetitive DNA sequences found in HETEROCHROMATIN, mainly near centromeres. They are composed of simple sequences (very short) (see MINISATELLITE REPEATS) repeated in tandem many times to form large blocks of sequence. Additionally, following the accumulation of mutations, these blocks of repeats have been repeated in tandem themselves. The degree of repetition is on the order of 1000 to 10 million at each locus. Loci are few, usually one or two per chromosome. They were called satellites since in density gradients, they often sediment as distinct, satellite bands separate from the bulk of genomic DNA owing to a distinct BASE COMPOSITION.Immunoglobulin Switch Region: A site located in the INTRONS at the 5' end of each constant region segment of a immunoglobulin heavy-chain gene where recombination (or rearrangement) occur during IMMUNOGLOBULIN CLASS SWITCHING. Ig switch regions are found on genes encoding all five classes (IMMUNOGLOBULIN ISOTYPES) of IMMUNOGLOBULIN HEAVY CHAINS.Bacteriophage lambda: A temperate inducible phage and type species of the genus lambda-like viruses, in the family SIPHOVIRIDAE. Its natural host is E. coli K12. Its VIRION contains linear double-stranded DNA with single-stranded 12-base 5' sticky ends. The DNA circularizes on infection.Genetic Diseases, Inborn: 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.DNA Mutational Analysis: Biochemical identification of mutational changes in a nucleotide sequence.Centromere: The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.Sequence Alignment: 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.Saccharomyces cerevisiae Proteins: Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.Genes, Bacterial: The functional hereditary units of BACTERIA.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Chromosome Segregation: The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.Siblings: Persons or animals having at least one parent in common. (American College Dictionary, 3d ed)Genetic Techniques: Chromosomal, biochemical, intracellular, and other methods used in the study of genetics.Synaptonemal Complex: The three-part structure of ribbon-like proteinaceous material that serves to align and join the paired homologous CHROMOSOMES. It is formed during the ZYGOTENE STAGE of the first meiotic division. It is a prerequisite for CROSSING OVER.Radiation Hybrid Mapping: A method for ordering genetic loci along CHROMOSOMES. The method involves fusing irradiated donor cells with host cells from another species. Following cell fusion, fragments of DNA from the irradiated cells become integrated into the chromosomes of the host cells. Molecular probing of DNA obtained from the fused cells is used to determine if two or more genetic loci are located within the same fragment of donor cell DNA.Exodeoxyribonuclease V: An ATP-dependent exodeoxyribonuclease that cleaves in either the 5'- to 3'- or the 3'- to 5'-direction to yield 5'-phosphooligonucleotides. It is primarily found in BACTERIA.DNA, Single-Stranded: A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.Chromosome Inversion: An aberration in which a chromosomal segment is deleted and reinserted in the same place but turned 180 degrees from its original orientation, so that the gene sequence for the segment is reversed with respect to that of the rest of the chromosome.Shiitake Mushrooms: Mushrooms in the order AGARICALES containing B vitamins, cortinelin, and the polysaccharide LENTINAN.Lupinus: A plant genus of the family FABACEAE that is a source of SPARTEINE, lupanine and other lupin alkaloids.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Bacterial Proteins: Proteins found in any species of bacterium.Sinapis: A plant genus of the family BRASSICACEAE. The common name of white mustard sometimes refers to other plants (MUSTARD PLANT).Haploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.Flounder: Common name for two families of FLATFISHES belonging to the order Pleuronectiformes: left-eye flounders (Bothidae) and right-eye flounders (Pleuronectidae). The latter is more commonly used in research.Sonchus: A plant genus of the family ASTERACEAE. Sesquiterpene lactone glucosides (SESQUITERPENES) have been found in it.Recombinational DNA Repair: Repair of DNA DAMAGE by exchange of DNA between matching sequences, usually between the allelic DNA (ALLELES) of sister chromatids.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Endodeoxyribonucleases: A group of enzymes catalyzing the endonucleolytic cleavage of DNA. They include members of EC 3.1.21.-, EC 3.1.22.-, EC 3.1.23.- (DNA RESTRICTION ENZYMES), EC 3.1.24.- (DNA RESTRICTION ENZYMES), and EC 3.1.25.-.Contig Mapping: Overlapping of cloned or sequenced DNA to construct a continuous region of a gene, chromosome or genome.Nelumbo: A plant genus of the family NELUMBONACEAE. The common name of lotus is also for LOTUS and NYMPHAEA.Gentianaceae: A plant family of the order Gentianales, subclass Asteridae, class Magnoliopsida.Sister Chromatid Exchange: An exchange of segments between the sister chromatids of a chromosome, either between the sister chromatids of a meiotic tetrad or between the sister chromatids of a duplicated somatic chromosome. Its frequency is increased by ultraviolet and ionizing radiation and other mutagenic agents and is particularly high in BLOOM SYNDROME.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.DNA, Cruciform: A cross-shaped DNA structure that can be observed under the electron microscope. It is formed by the incomplete exchange of strands between two double-stranded helices or by complementary INVERTED REPEAT SEQUENCES that refold into hairpin loops on opposite strands across from each other.Brassica rapa: A plant species cultivated for the seed used as animal feed and as a source of canola cooking oil.Chromosomes, Human, Pair 20: A specific pair of GROUP F CHROMOSOMES of the human chromosome classification.DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.Paranoid Personality Disorder: A personality disorder characterized by the avoidance of accepting deserved blame and an unwarranted view of others as malevolent. The latter is expressed as suspiciousness, hypersensitivity, and mistrust.Genotyping Techniques: Methods used to determine individuals' specific ALLELES or SNPS (single nucleotide polymorphisms).Chromosome Deletion: Actual loss of portion of a chromosome.Chromosomes, Human, Pair 9: A specific pair of GROUP C CHROMSOMES of the human chromosome classification.Eucalyptus: A genus of trees of the Myrtaceae family, native to Australia, that yields gums, oils, and resins which are used as flavoring agents, astringents, and aromatics.Genome-Wide Association Study: 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.Nucleic Acid Hybridization: Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)Genes, Fungal: The functional hereditary units of FUNGI.Gene Rearrangement, B-Lymphocyte: Ordered rearrangement of B-lymphocyte variable gene regions coding for the IMMUNOGLOBULIN CHAINS, thereby contributing to antibody diversity. It occurs during the differentiation of the IMMATURE B-LYMPHOCYTES.Transformation, Genetic: Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.Random Amplified Polymorphic DNA Technique: 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.Nucleic Acid Heteroduplexes: Double-stranded nucleic acid molecules (DNA-DNA or DNA-RNA) which contain regions of nucleotide mismatches (non-complementary). In vivo, these heteroduplexes can result from mutation or genetic recombination; in vitro, they are formed by nucleic acid hybridization. Electron microscopic analysis of the resulting heteroduplexes facilitates the mapping of regions of base sequence homology of nucleic acids.Chromosomes, Human, Pair 14: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Mutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.Exons: 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.Chromosomes, Human, Pair 22: A specific pair of GROUP G CHROMOSOMES of the human chromosome classification.Minisatellite Repeats: 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.Syndrome: A characteristic symptom complex.Gene Order: The sequential location of genes on a chromosome.Inheritance Patterns: The different ways GENES and their ALLELES interact during the transmission of genetic traits that effect the outcome of GENE EXPRESSION.Genetic Testing: 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.Lecythidaceae: A plant family of the order Lecythidales, subclass Dilleniidae, class Magnoliopsida.Cosmids: Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.Age of Onset: The age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.Genetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.Fibromatosis, Gingival: Generalized or localized diffuse fibrous overgrowth of the gingival tissue, usually transmitted as an autosomal dominant trait, but some cases are idiopathic and others produced by drugs. The enlarged gingiva is pink, firm, and has a leather-like consistency with a minutely pebbled surface and in severe cases the teeth are almost completely covered and the enlargement projects into the oral vestibule. (Dorland, 28th ed)Mutagenesis, Insertional: Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.Chromosomes, Human, Pair 13: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.Epidermolysis Bullosa Dystrophica: Form of epidermolysis bullosa characterized by atrophy of blistered areas, severe scarring, and nail changes. It is most often present at birth or in early infancy and occurs in both autosomal dominant and recessive forms. All forms of dystrophic epidermolysis bullosa result from mutations in COLLAGEN TYPE VII, a major component fibrils of BASEMENT MEMBRANE and EPIDERMIS.Endonucleases: Enzymes that catalyze the hydrolysis of the internal bonds and thereby the formation of polynucleotides or oligonucleotides from ribo- or deoxyribonucleotide chains. EC 3.1.-.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Genomic Instability: An increased tendency of the GENOME to acquire MUTATIONS when various processes involved in maintaining and replicating the genome are dysfunctional.

*Genetic linkage

The greater the frequency of recombination (segregation) between two genetic markers, the further apart they are assumed to be ... Recombination frequency is a measure of genetic linkage and is used in the creation of a genetic linkage map. Recombination ... Thus, the use of recombination frequencies has been used to develop linkage maps or genetic maps. However, it is important to ... the recombination frequency is 50% since 2 of the 4 gametes were recombinant gametes. The recombination frequency will be 50% ...

*Genetic hitchhiking

Genetic draft generates a different allele frequency spectrum to genetic drift. The Y chromosome does not undergo recombination ... A greater distance would increase the chance of recombination separating M from A*, leaving M alone with any deleterious ... any other nearby polymorphisms that are in linkage disequilibrium will tend to change their allele frequencies too. Selective ... Genetic hitchhiking, also called genetic draft or the hitchhiking effect, is when an allele changes frequency not because it ...

*Complete linkage

Through recombination, daughter cells have the greatest amount of genetic diversity. (Click Here for a video tutorial ... A centimorgan is equivalent to the percent of recombination. two loci with 2% recombination frequency are located 2 ... In the absence of recombination, only parental phenotypes are expected. Genetic Linkage is the tendency of alleles, which are ... This process is known as genetic recombination. The rate of recombination of two discrete loci corresponds to their physical ...

*Chromosomal crossover

This leads to the notion of "genetic distance", which is a measure of recombination frequency averaged over a (suitably large) ... For fixed set of genetic and environmental conditions, recombination in a particular region of a linkage structure (chromosome ... Morgan immediately saw the great importance of Janssens' cytological interpretation of chiasmata to the experimental results of ... "genetic recombination". Genetic Recombination Smith, George P. (1976-01-01). "Evolution of Repeated DNA Sequences by Unequal ...

*Hill-Robertson effect

Clonal interference Genetic hitchhiking Hill, W. G., and A. Robertson, 1966 The effect of linkage on limits to artificial ... It provides an explanation as to why there may be an evolutionary advantage to genetic recombination. In a population of finite ... The chance of this happening depends on the frequency of new mutations, and on the size of the population, but is in general ... Provided there are no negative epistatic effects of carrying both, individuals of genotype AB will have a greater selective ...

*Molecular evolution

Recombination counteracts physical linkage between adjacent genes, thereby reducing genetic hitchhiking. The resulting ... Genetic drift is the change of allele frequencies from one generation to the next due to stochastic effects of random sampling ... Selection occurs when organisms with greater fitness, i.e. greater ability to survive or reproduce, are favored in subsequent ... Recombination is a process that results in genetic exchange between chromosomes or chromosomal regions. ...

*CCR5

Second, genetic linkage analysis indicates that the mutation occurs on a homogenous genetic background, implying that ... Two studies have used linkage analysis to estimate the age of the CCR5 Δ32 deletion, assuming that the amount of recombination ... CCR5 Δ32 has an (heterozygote) allele frequency of 10% in Europe, and a homozygote frequency of 1%. The CCR5 Δ32 allele is ... Individuals heterozygous for the mutant allele have a greater than 50% reduction in functional CCR5 receptors on their cell ...

*HLA A1-B8-DR3-DQ2

Thus, A1::DQ2 haplotype is both long and shows greater deficiency of recombination (called linkage disequilibrium). The ... genetic) linkage between A1 and B1, this was extended to Cw7 locus. And while the level of A-B linkage in general was nowhere ... DQ2 in frequency. Genetics of recombination in humans suggests that common haplotypes of this length that Cw7-B8 component ... had already undergone significant recombination and is nearly equal in frequency to HLA A2-Cw7::DQ6 bearing version. In the US ...

*Linkage disequilibrium

... the rate of recombination, the rate of mutation, genetic drift, the system of mating, population structure, and genetic linkage ... Note that these are relative frequencies. One can use the above frequencies to determine the frequency of each of the alleles: ... are greater than zero. Linkage disequilibrium corresponds to D A B ≠ 0 {\displaystyle D_{AB}\neq 0} . In the case D A B = 0 {\ ... In spite of its name, linkage disequilibrium may exist between alleles at different loci without any genetic linkage between ...

*Linkage based QTL mapping

The principle behind genetic mapping that uses an experimental cross is the occurrence of recombination events between genetic ... the marker and QTL allele frequencies must be estimated from the data, inbreeding loops may exist in the pedigree, and markers ... methods that fully account for complex relationships between individuals are expected to provide greater power to detect QTL ( ... MapQTL R/qtl WinQTL cartographer QTL mapping Family based QTL mapping Genetic linkage. ...

*Outline of evolution

Variation Genetic variation Genetic diversity Gene frequency Polymorphism (biology) Key concepts Hardy-Weinberg law Genetic ... Mosaic evolution Parallel evolution Quantum evolution Genetic recombination Recurrent evolution Robustness (evolution) ... Terrestrial biodiversity tends to be greater near the equator, which seems to be the result of the warm climate and high ... linkage Identity by descent Linkage disequilibrium Fisher's fundamental theorem Neutral theory Shifting balance theory Price ...

*Single-nucleotide polymorphism

... of the SNP that constitutes the most favorable genetic adaptation. Other factors, like genetic recombination and mutation rate ... Within a population, SNPs can be assigned a minor allele frequency - the lowest allele frequency at a locus that is observed in ... Linkage disequilibrium (LD), a term used in population genetics, indicates non-random association of alleles at two or more ... SNPs' greatest importance in biomedical research is for comparing regions of the genome between cohorts (such as with matched ...

*HLA-DR

The table below provides links to subpages with information about distribution, genetic linkage and disease association for the ... genetic recombination. Functional motifs in genes are exchanged to form new alleles, and frequently new, functionally different ... Identification of these antigens has led to greater success and longevity in organ transplant. Antigens most responsible for ... "New HLA haplotype frequency reference standards: high-resolution and large sample typing of HLA DR-DQ haplotypes in a sample of ...

*Yellowface II budgerigar mutation

... see genetic linkage). The cross-over value (COV) or recombination frequency between the Dark and Blue loci is commonly stated ... and tends to leak into the body feathers to a greater extent. Although not recognised as such at the time, it is possible that ...

*Masatoshi Nei

... interaction natural selection always tends to enhance the linkage intensity between genetic loci or maintain the same linkage ... Gene frequency data. J. Mol. Evol. 19:153-170. Nei, M. (1973) Analysis of gene diversity in subdivided populations. Proc. Natl ... He then observed that the average recombination value per genome is generally lower in higher organisms than in lower organisms ... there was a great controversy over the mechanism of protein evolution and the maintenance of protein polymorphism. Nei and his ...

*Evolution

Mechanisms that can lead to changes in allele frequencies include natural selection, genetic drift, genetic hitchhiking, ... Recombination and reassortment do not alter allele frequencies, but instead change which alleles are associated with each other ... Great Discoveries (1st ed.). New York: Atlas Books/W. W. Norton & Company. ISBN 978-0-393-05981-6. LCCN 2006009864. OCLC ... which is called their linkage disequilibrium. A set of alleles that is usually inherited in a group is called a haplotype. This ...

*Genetic load

Recombination load arises through unfavorable combinations across multiple loci that appear when favorable linkage ... Ignoring frequency-dependent selection, the genetic load L {\displaystyle L} may be calculated as: L = w max − w ¯ w max {\ ... whose damage in combination is greater than that predicted from considering them in isolation. Migration load is the result of ... Haag, C. R.; Roze, D. (2007). "Genetic load in sexual and asexual diploids: segregation, dominance and genetic drift". Genetics ...

*HLA B7-DR15-DQ6

... linkage disequilibrium with other HLA loci and population genetic affinities". Eur J Immunogenet. 21 (3): 143-57. doi:10.1111/j ... DR15:DQ6 frequencies peak in central Asia, and it is suspect that this may be a point of Eurasian spread westward into Europe. ... The DR15-DQ6 haplotype may afford some greater protection against the progression of HIV. However, the haplotype is a risk ... Chromosomal recombination fragments multigene haplotypes as the distance to that ancestor increases in number of generations. ...

*Yellowface I budgerigar mutation

... see genetic linkage). The cross-over value (COV) or recombination frequency between the Dark and Blue loci is commonly stated ... nor does it leak onto the breast to as great an extent. The Yellowface I Cobalt and Yellowface I Mauve varieties have similar ...

*HLA DR3-DQ2

DQ8 is helpful because of the strong linkage disequilibrium (LD) of the "super B8" haplotype. Unclear genetic information has ... DR3-DQ2 is associated with probably the greatest frequency of autoimmune occurrence relative to any other haplotype. The DQA1* ... DQ2.5 appears to be derived from DQ2.2 by gene recombination. One haplotype DQA1*0501:DQB1*0202 can be found in Africa ... The highest frequency of this node is in Western Ireland. Despite its high frequency Ireland is not likely the source of the ...

*Tag SNP

... processes that influence linkage disequilibrium include genetic linkage, epistatic natural selection, rate of recombination, ... The SNP frequency and recombination rates are known to vary across the genome and some studies have reported LD distances much ... To pinpoint the causal SNPs we need a greater resolution in the selection of haplotype blocks. Since whole genome sequencing ... An important factor to consider when planning a genetic study is the frequency and risk incurred by specific alleles. These ...

*Pleiotropy

... scientists instead focused on how uncoupled phenotypic traits can be affected by genetic recombination and mutations, applying ... This linkage is further evidenced by the fact that two of the genes, HAO1 and BMP2, affecting medullary bone (the part of the ... The frequency of this disease varies greatly. Specifically, in the United States, PKU is found at a rate of nearly 1 in 10,000 ... However, antagonistic pleiotropy also lends greater evolutionary "staying power" to genes controlling beneficial traits, since ...

*Microsatellite

They are also used in genetic linkage analysis to locate a gene or a mutation responsible for a given trait or disease. ... Null alleles in this case can sometimes be indicated by an excessive frequency of homozygotes causing deviations from Hardy- ... If there is a large size difference between individual alleles, then there may be increased instability during recombination at ... Their continued advantage lies in their greater allelic diversity than biallelic SNPs, thus microsatellites can differentiate ...

*Reinforcement (speciation)

Later population genetic and quantitative genetic studies were conducted showing that completely unfit hybrids lead ... In direct selection, the frequency of the selected allele is favored to the extreme. In cases where an allele is indirectly ... selected, its frequency increases due to a different linked allele experiencing selection (linkage disequilibrium). The ... An alternative model exists to address the antagonism of recombination, as it can reduce the association between the alleles ...

*Genetic screen

When the DNA clone is at or close to the mutant allele, the recombination frequency should be close to zero. If the chromosome ... Defined genetic backgrounds allow researchers to identify and locate affected genes in mutant individuals with greater ... Initially, the candidate region can be defined using techniques such as linkage analysis, and positional cloning is then used ... For each new DNA clone a polymorphism is identified and tested in the mapping population for its recombination frequency ...

*DNA damage theory of aging

... allowing greater accumulation of DNA damages, causes premature aging; and that increased DNA repair facilitates greater ... In a population of cells, mutant cells will increase or decrease in frequency according to the effects of the mutation on the ... Werner syndrome (WS), a premature aging condition in humans, is caused by a genetic defect in a RecQ helicase that is employed ... Specifically, Acharya noted that double-strand breaks and a "cross-linkage joining both strands at the same point is ...
Recombination directionality factors (RDFs), or excisionases, are essential players of prophage excisive recombination. Despite the essentially catalytic role of the integrase in both integrative and excisive recombination, RDFs are required to direct the reaction towards excision and to prevent re-integration of the prophage genome when entering a lytic cycle. KplE1, HK620 and numerous (pro)phages that integrate at the same site in enterobacteria genomes (such as the argW tRNA gene) all share a highly conserved recombination module. This module comprises the attL and attR recombination sites and the RDF and integrase genes. The KplE1 RDF was named TorI after its initial identification as a negative regulator of the tor operon. However, it was characterized as an essential factor of excisive recombination. In this study, we designed an extensive random mutagenesis protocol of the torI gene and identified key ...
Meiosis is a cell division process that produces haploid gametes from diploid cells. Several important meiotic events take place during prophase of meiosis I, most important being homologous chromosome pairing, meiotic recombination and formation of the synaptonemal complex (SC). These processes assure proper segregation of the homologous chromosomes into the haploid germ cells. Improper segregation of the homologos can cause chromosomal abnormality (aneuploidy), which causes various human disorders, notably mental retardation and pregnancy loss.. This thesis focuses on the relationship between recombination and the formation of SCs, aggregates of SC-related materials (polycomplexes) and recombination enzymes during meiosis. We have investigated SC formation in the absence of recombination, nature of polycomplexes and recombination enzymes in relation to the SCs structures and recombination nodules (RNs) in ...
60125DNAUnknownDescription of Unknown Recombination products oligonucleotide sequence 1rkycwgcttt yktrtacnaa stsgb 25225DNAUnknownDescription of Unknown Recombination products oligonucleotide sequence 2agccwgcttt yktrtacnaa ctsgb 25325DNAUnknownDescription of Unknown Recombination products oligonucleotide sequence 3gttcagcttt cktrtacnaa ctsgb 25425DNAUnknownDescription of Unknown Recombination products oligonucleotide sequence 4agccwgcttt cktrtacnaa gtsgb 25525DNAUnknownDescription of Unknown Recombination products oligonucleotide sequence 5gttcagcttt yktrtacnaa gtsgb 25625DNAUnknownDescription of Unknown Recombination products oligonucleotide sequence 6agcctgcttt tttgtacaaa cttgt 25725DNAUnknownDescription of Unknown Recombination products oligonucleotide sequence 7agcctgcttt cttgtacaaa cttgt 25825DNAUnknownDescription of Unknown Recombination products oligonucleotide ...
In the nematode Caenorhabditis elegans, recombination suppression in translocation heterozygotes is severe and extensive. We have examined the meiotic properties of two translocations involving chromosome I, szT1(I;X) and hT1(I;V). No recombination was observed in either of these translocation heterozygotes along the left (let-362-unc-13) 17 map units of chromosome I. Using half-translocations as free duplications, we mapped the breakpoints of szT1 and hT1. The boundaries of crossover suppression coincided with the physical breakpoints. We propose that DNA sequences at the right end of chromosome I facilitate pairing and recombination. We use the data from translocations of other chromosomes to map the location of pairing sites on four other chromosomes. hT1 and szT1 differed markedly in their effect on recombination adjacent to the crossover suppressed region. hT1 had no effect on recombination in the adjacent interval. In ...
Asthma and allergy are complex multifactorial disorders, with both genetic and environmental components determining disease expression. The use of molecular genetics holds great promise for the identification of novel drug targets for the treatment of asthma and allergy. Genome-wide linkage studies have identified a number of potential disease susceptibility loci but replication remains inconsistent. The aim of the current study was to complete a meta-analysis of data from genome-wide linkage studies of asthma and related phenotypes and provide inferences about the consistency of results and to identify novel regions for future gene discovery. The rank based genome-scan meta-analysis (GSMA) method was used to combine linkage data for asthma and related traits; bronchial hyper-responsiveness (BHR), allergen positive skin prick test (SPT) and total serum Immunoglobulin E (IgE) from nine Caucasian asthma populations. ...
TY - JOUR. T1 - Meta-analysis of five genome-wide linkage studies for body mass index reveals significant evidence for linkage to chromosome 8p. AU - Johnson, L.. AU - Luke, A.. AU - Deng, H. W.. AU - Mitchell, B. D.. AU - Comuzzie, A. G.. AU - Cole, S. A.. AU - Blangero, J.. AU - Perola, M.. AU - Teare, M. Dawn. PY - 2005/4. Y1 - 2005/4. N2 - OBJECTIVE: To perform a meta-analysis of genome-wide linkage scans using body mass index (BMI) to identify genetic loci predisposing to obesity. DATA: A total of 13 published genome scans on obesity have used BMI as their primary end point. Five of these 13 groups agreed to provide detailed results from their scans that were required for a meta-analysis. Collectively, these five studies included a total of 2814 individuals from 505 families. METHODS: The results of the five studies were analysed using the GSMA (genome scans meta-analysis) method. RESULTS: The analysis revealed significant evidence for ...
TY - JOUR. T1 - The association of cell cycle checkpoint 2 variants and kidney function. T2 - Findings of the family blood pressure program and the atherosclerosis risk in communities study. AU - Franceschini, Nora. AU - North, Kari E.. AU - Arnett, Donna. AU - Pankow, James S.. AU - Chung, Jay H.. AU - Baird, Lisa. AU - Leppert, Mark F.. AU - Eckfeldt, John H.. AU - Boerwinkle, Eric. AU - Gu, C. Charles. AU - Lewis, Cora E.. AU - Myers, Richard H.. AU - Turner, Stephen T.. AU - Weder, Alan. AU - Kao, W. H Linda. AU - Mosley, Thomas H.. AU - Chakravarti, Aravinda. AU - Kramer, Holly. AU - Zhang, Jinghui. AU - Hunt, Steven C.. PY - 2009/5. Y1 - 2009/5. N2 - Background: Recent experimental evidence suggests that DNA damage and cell cycle regulatory proteins are involved in kidney injury and apoptosis. The checkpoint 2 gene (CHEK2) is an important transducer in DNA damage signaling pathways in response to injury, and therefore, CHEK2 variants may affect susceptibility to kidney disease.MethodsWe ...
Red clover (Trifolium pratense L.) is a major forage legume that has a strong self-incompatibility system and exhibits high genetic diversity within populations. For several crop species, integrated consensus linkage maps that combine information from multiple mapping populations have been developed. For red clover, three genetic linkage maps have been published, but the information in these existing maps has not been integrated. A consensus linkage map was constructed using six mapping populations originating from eight parental accessions. Three of the six mapping populations were established for this study. The integrated red clover map was composed of 1804 loci, including 1414 microsatellite loci, 181 amplified fragment length polymorphism (AFLP) loci and 204 restriction fragment length polymorphism (RFLP) loci, in seven linkage groups. The average distance between loci and the total length of the ...
Definition of Genetic linkage in the Financial Dictionary - by Free online English dictionary and encyclopedia. What is Genetic linkage? Meaning of Genetic linkage as a finance term. What does Genetic linkage mean in finance?
Analysis of meiotic tetrads is routinely used to determine genetic linkage in various fungi. Here we apply tetrad analysis to the study of genetic linkage in a vertebrate. The half-tetrad genotypes of gynogenetic diploid zebrafish produced by early-pressure (EP) treatment were used to investigate the linkage relationships of two recessive pigment pattern mutations, leopard (leo) and rose (ros). The results showed that ros is tightly linked to its centromere and leo maps 31 cM from its centromere. Analysis of half-tetrads segregating for ros and leo in repulsion revealed no homozygous ros individuals among 32 homozygous leo half-tetrads--i.e., a parental ditype (PD) to nonparental ditype (NPD) ratio of 32:0. This result shows that ros is linked to leo, a mutation previously mapped to Linkage Group I. Investigation of PCR-based DNA polymorphisms on Linkage Group I confirmed ...
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Looking for online definition of Adult polycystic kidneys in the Medical Dictionary? Adult polycystic kidneys explanation free. What is Adult polycystic kidneys? Meaning of Adult polycystic kidneys medical term. What does Adult polycystic kidneys mean?
Looking for sex linkage? Find out information about sex linkage. That sex of some species which produces two or more different kinds of gametes that differ in their sex chromosome content Explanation of sex linkage
A genetic linkage map is a valuable tool for QTL mapping, map-based gene cloning, comparative mapping, and whole genome assembly. Alfalfa, one of the most important forage crops in the world, is autotetraploid, allogamous, and highly heterozygous, characteristics that have impeded the construction of a high density linkage map using traditional genetic marker systems. Using genotyping-by-sequencing (GBS), we constructed low-cost, reasonably high-density linkage maps for both maternal and paternal parental genomes of an autotetraploid alfalfa F1 population. The resulting maps contain 3,591 SNP markers on 64 linkage groups across both parents, with an average density of one marker per 1.5 and 1.0 cM for the maternal and paternal haplotype maps, respectively. Chromosome assignments were made based on homology of markers to the Medicago truncatula genome. Four linkage groups representing the ...
Cassava is an important tuber crop grown mainly in the tropical and sub-tropical regions. The crop is a source of calories for over 500 million people worldwide. To improve the crop, genetic improvement through breeding is necessary. The use of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) are the powerful tools to generate a linkage map in cassava. F1 mapping population from 96 1089A and TME 117 was developed with 180 progenies. To produce the linkage map, parental lines were screened with over 200 SSR markers and the polymorphic markers were used on the progenies. Of 717 SNP markers used, 347 were polymorphic. 253 markers comprising of 248 SNP and 5 SSR markers were used. 18 linkage groups were drawn with an average of 14 markers on each chromosome and the average marker distance of 6.5cM. The total length of the map was 1,493cM. SNP markers are many and could be easily used to construct a genetic ...
Extended pedigrees are not only very useful to identify disease genes for rare Mendelian conditions, but they may also help unravel the genetics of complex diseases such as schizophrenia. In this study we performed genome-wide multipoint non-parametric linkage (NPL) score calculations using 825 microsatellites and 5,366 single nucleotide polymorphisms (SNPs), respectively, and searched for haplotypes shared by affected individuals, in three multiplex families including 29 genotyped affected individuals which in total contains 49 relative pairs useful for linkage studies. The most consistent results for microsatellites and SNPs were observed on 2q12.3-q14.1 (NPL scores 2.0, empirical P-value 0.009). However, the overall highest NPL score was observed on chromosome 2q33.3 using SNPs (NPL score 2.2, empirical P-value 0.007). Other chromosomal regions were detected on 5q15-q22.1, with microsatellites (NPL scores 1.7, empirical P-value 0.021) and with SNPs (NPL ...
OBJECTIVE: The purpose of this study was to find loci for major depression via linkage analysis of a large sibling pair sample. METHOD: The authors conducted a genome-wide linkage analysis of 839 families consisting of 971 affected sibling pairs with severe recurrent major depression, comprising waves I and II of the Depression Network Study cohort. In addition to examining affected status, linkage analyses in the full data set were performed using diagnoses restricted by impairment severity, and association mapping of hits in a large case-control data set was attempted. RESULTS: The authors identified genome-wide significant linkage to chromosome 3p25-26 when the diagnoses were restricted by severity, which was a maximum LOD score of 4.0 centered at the linkage marker D3S1515. The linkage signal identified was genome-wide significant after correction for the multiple phenotypes tested, although subsequent ...
Attention deficit hyperactivity disorder (ADHD) is a childhood onset disorder, for which there is good evidence that genetic factors contribute to the aetiology. Recently reported linkage findings suggested evidence of a susceptibility locus on chromosome 16p13 (maximum LOD score of 4.2, P=5 x 10(-6 …
In population genetics, linkage disequilibrium is the non-random association of alleles at different loci in a given population. Loci are said to be in linkage disequilibrium when the frequency of association of their different alleles is higher or lower than what would be expected if the loci were independent and associated randomly.[1]. Linkage disequilibrium is influenced by many factors, including selection, the rate of recombination, the rate of mutation, genetic drift, the system of mating, population structure, and genetic linkage. As a result, the pattern of linkage disequilibrium in a genome is a powerful signal of the population genetic processes that are structuring it.. In spite of its name, linkage disequilibrium may exist between alleles at different loci without any genetic ...
BACKGROUND:. Meiotic linkage maps are the foundation of both linkage and linkage disequilibrium studies for mapping disease genes. Despite the importance of precise maps, existing genome-wide linkage maps were built using only a small collection of pedigrees, and so have wide confidence intervals surrounding estimates of map distance. Incorrect marker order and map distances can have a profound effect on linkage analyses. Using a sex-averaged map instead of a sex-specific map biases the lod scores upward, markedly increasing the false positive rate. Since it is very costly to follow-up many false-positive results, there is a clear need for more precise and accurate sex-specific genetic maps. Accurate estimates of meiotic map distance cannot be obtained by any means other than by linkage analysis using genotype data.. The study is in response to a Request for Applications entitled NHLBI ...
CONTEXT: Recently, a quantitative trait locus for stature was reported on chromosome 3p26 in patients with type 2 diabetes. OBJECTIVE: Given that ghrelin is a peptide involved in GH release and located on 3p26, we hypothesized that variation within its gene (GHRL) may be responsible for the quantitative trait locus on 3p26. DESIGN: The evidence for linkage around GHRL was refined with the genotyping of an additional four microsatellites (D3S4545, D3S1537, D3S1597, and D3S3611), giving a total of 27 markers, followed by multipoint variance components linkage analysis. Probands from the linkage families were typed for five common single nucleotide polymorphisms (SNPs) within GHRL and tested for association with adult stature using haplotype trend regression. RESULTS: The maximum multipoint evidence for linkage between adult stature and the 27 microsatellites yielded an LOD score of 2.58 (P = 0.0003) between D3S1297 and D3S1304. Five common ...
TY - JOUR. T1 - Evidence for asthma susceptibility genes on chromosome 11 in an African-American population. AU - Huang, Shau Ku. AU - Mathias, Rasika A.. AU - Ehrlich, Eva. AU - Plunkett, Beverly. AU - Liu, Xin. AU - Cutting, Garry R.. AU - Wang, Xin Jing. AU - Li, Xiao Dong. AU - Togias, Alkis. AU - Barnes, Kathleen C.. AU - Malveaux, Floyd. AU - Rich, Stephen. AU - Mellen, Beverly. AU - Lange, Ethan. AU - Beaty, Terri H.. PY - 2003/7/1. Y1 - 2003/7/1. N2 - Initial genome-wide scan data provided suggestive evidence for linkage of the asthma phenotype in African-American (AA), but not Caucasian, families to chromosome 11q markers (peak at D11S1985; LOD=2). To refine this region, mapping analysis of 91 AA families (51 multiplex families and 40 asthmatic case-parent trios) was performed with an additional 17 markers flanking the initial peak linkage marker. Multipoint analyses of the 51 multiplex families yielded significant evidence of linkage with a peak ...
Recombination frequency (θ) is when crossing-over will take place between two loci (or genes) during meiosis. Recombination frequency is a measure of genetic linkage and is used in the creation of a genetic linkage map. A centimorgan (cM) is a unit that describes a recombination frequency of 1%.. During meiosis, chromosomes assort randomly into gametes, such that the segregation of alleles of one gene is independent of alleles of another gene. This is stated in Mendels Second Law and is known as the law of independent assortment. The law of independent assortment always holds true for genes that are located on different chromosomes, but for genes that are on the same chromosome, it does not always hold true.. As an example of independent assortment, consider the crossing of the pure-bred homozygote parental strain with genotype AABB with a ...
Patient with adult polycystic kidney disease may present with bilateral enlargement of the kidneys on bimanual palpitation. The common symptoms and signs of adult polycystic kidney disease may include hypertension, pain in the loin or flank region due t
It is well established that gene interactions influence common human diseases, but to date linkage studies have been constrained to searching for single genes across the genome. We applied a novel approach to uncover significant gene-gene interactions in a systematic two-dimensional (2D) genome-scan of essential hypertension. The study cohort comprised 2076 affected sib-pairs and 66 affected half-sib-pairs of the British Genetics of HyperTension study. Extensive simulations were used to establish significance thresholds in the context of 2D genome-scans. Our analyses found significant and suggestive evidence for loci on chromosomes 5, 9, 11, 15, 16 and 19, which influence hypertension when gene-gene interactions are taken into account (5q13.1 and 11q22.1, two-locus lod score=5.72; 5q13.1 and 19q12, two-locus lod score=5.35; 9q22.3 and 15q12, two-locus lod score=4.80; 16p12.3 and 16q23.1, two-locus lod score=4.50). For each significant and suggestive pairwise interaction, the ...
Bipolar affective disorder is one of the most common mental illnesses with a population prevalence of approximately 1%. The disorder is genetically complex, with an increasing number of loci being implicated through genetic linkage studies. However, the specific genetic variations and molecules involved in bipolar susceptibility and pathogenesis are yet to be identified. Genetic linkage analysis has identified a bipolar disorder susceptibility locus on chromosome 4q35, and the interval harbouring this susceptibility gene has been narrowed to a size that is amenable to positional cloning. We have used the resources of the Human Genome Project (HGP) and Celera Genomics to identify overlapping sequenced BAC clones and sequence contigs that represent the region implicated by linkage analysis. A combination of bioinformatic tools and laboratory techniques have been applied to annotate this DNA ...
We analyzed a large group of Finnish type 2 diabetic families and found evidence for linkage to chromosome 20. Three linkage peaks were seen after analyses of diabetes and diabetes-related traits. These linkages were at approximately 0-25 cM, 50-60 cM, and 63-72 cM respectively from the marker D20S103. Although the second and third peaks could be explained by a single susceptibility locus, evidence for linkage on both arms on chromosome 20 argues for the presence of more than one susceptibility locus. As far as we know, we are the first group to show evidence for linkage to the proximal p arm of chromosome 20 in type 2 diabetes. Most of our evidence comes from families with affected sibships greater than two. Ordered subset analyses of our data revealed that a small number of families, with high or low values of important diabetes-related traits, give rise to large lod scores near the three peaks. These ...
Background: Multiple sclerosis (MS) is a disease widely believed to be autoimmune in nature. Genetic-epidemiological studies implicate susceptibility genes in pathogenesis, although non-MHC susceptibility linkages have been difficult to confirm. Insight into pathways intrinsic to other complex diseases has come from the genetic analysis of large, autosomal dominant kindreds. Here we present a genetic study of a large and unique kindred in which MS appears to follow an autosomal dominant pattern of inheritance with consistent penetrance in 4 generations. Methods: Eighty-two individuals of this 370 member family were genotyped with 681 microsatellite markers spanning the genome with an average spacing of 5.3 cM. Results: Parametric linkage analysis was performed and no significant LOD score (LOD,3.3) was observed. For a rare dominant disease model with reduced penetrance, 99.6% of the genome was excluded at a lod score ,-1 and ...
We assembled the first chromosome level linkage map for the Australian snapper Chrysophrys auratus. Proof checking the marker order against the snapper de novo genome assembly indicated that the linkage groups were of high quality. QTL mapping revealed eight markers on three linkage groups that were significantly associated with growth. Three candidate genes for growth were located on the same linkage groups as these QTL. These genomic resources will be used to inform the selective breeding program in New Zealand and will form the basis of further genomic investigation in snapper.. Linkage maps are essential for genomic and genetic studies, and have been used extensively to derive the order and spatial position of markers (Cnaani et al. 2004; Greenwood et al. 2011; Boulton et al. 2011). Historically, most first generation linkage maps in fish have been constructed with just a handful or a ...
The chromosomal localization of the gene for Thomsen disease, an autosomal dominant form of myotonia congenita, is unknown. Electrophysiologic data in Thomsen disease point to defects in muscle-membrane ion-channel function. A mouse model of myotonia congenita appears to result from transposon inactivation of a muscle chloride-channel gene which maps to a region of mouse chromosome 6. The linkage group containing this gene includes several loci which have human homologues on human chromosome 7q31-35 (synteny), and this is a candidate region for the Thomsen disease locus. Linkage analysis of Thomsen disease to the T-cell-receptor beta (TCRB) locus at 7q35 was carried out in four pedigrees (25 affected and 23 unaffected individuals) by using a PCR-based dinucleotide repeat polymorphism in the TCRB gene. Two-point linkage analysis between Thomsen disease and TCRB showed a maximum cumulative lod score of 3.963 at a recombination fraction of .10 ...
Owing to the complexity of the genetic models underlying complex traits, model-free linkage methods, which do not require the specification of a disease model, are a popular choice. With these methods, inclusion of covariates increases the power to detect linkage [1], provided that the covariates reflect underlying locus heterogeneity. The method allows the genetic relative risk to depend on the covariate so that, in effect, the allele sharing at the marker locus differs for different values of the covariate. A general conditional-logistic model developed by Olson [2] provides a unified framework to incorporate covariates, and this model is implemented in LODPAL (SAGE, version 6.1.0) [3]. A modified one-parameter model has been proposed [4], so that only one additional parameter per covariate is required.. To identify single-nucleotide polymorphisms (SNPs) that may explain the observed linkage signals, several researchers ...
BACKGROUND: Numerous studies suggest genetic influences on sleepiness and circadian rhythms. The Sleep Heart Health Study collected questionnaire data on sleep habits and sleepiness from 2848 Framingham Heart Study Offspring Cohort participants. More than 700 participants were genotyped using the Affymetrix 100K SNP GeneChip, providing a unique opportunity to assess genetic linkage and association of these traits. METHODS: Sleepiness (defined as the Epworth Sleepiness Scale score), usual bedtime and usual sleep duration were assessed by self-completion questionnaire. Standardized residual measures adjusted for age, sex and BMI were analyzed. Multipoint variance components linkage analysis was performed. Association of SNPs to sleep phenotypes was analyzed with both population-based and family-based association tests, with analysis limited to 70,987 autosomal SNPs with minor allele frequency ≥10%, call rate ≥80%, and no ...
TY - JOUR. T1 - Identification of a locus, distinct from RDS-peripherin, for autosomal recessive retinitis pigmentosa on chromosome 6p. AU - Knowles, James A.. AU - Shugart, Yin. AU - Banerjee, Poulabi. AU - Gilliam, T. Conrad. AU - Lewis, Charles A.. AU - Jacobson, Samuel G.. AU - Ott, Jurg. PY - 1994/8. Y1 - 1994/8. N2 - We performed a genomic search for linkage to autosomal recessive retinitis pigmentosa in a large pedigree obtained from the Dominican Republic using microsatellite markers. Regions of the genome known to contain genes for retinitis pigmentosa were preferentially tested. One of these regions, on chromosome 6p, which contains the gene for peripherin, gave positive lod scores. Use of a mononucleotide repeat polymorphism in the peripherin gene excluded this locus. Two- and multi-point analyses suggest that the most likely location for the disease gene is near D6S291, which is located approximately 20 centimorgans telomeric from peripherin.. AB - We performed a genomic search ...
Here we report recruitment of a three-generation Romani (Gypsy) family with autosomal dominant cone-rod dystrophy (adCORD). Involvement of known adCORD genes was excluded by microsatellite (STR) genotyping and linkage analysis. Subsequently, two independent total-genome scans using STR markers and single-nucleotide polymorphisms (SNPs) were performed. Haplotype analysis revealed a single 6.7-Mb novel locus between markers D10S1757 and D10S1782 linked to the disease phenotype on chromosome 10q26. Linkage analysis gave a maximum LOD score of 3.31 for five fully informative STR markers within the linked interval corresponding to the expected maximum in the family. Multipoint linkage analysis of SNP genotypes yielded a maximum parametric linkage score of 2.71 with markers located in the same chromosomal interval. There is no previously mapped CORD locus in this interval, and therefore the data reported here is novel and likely to identify a new ...
Title: Second generation of catfish genetic linkage map and integration of catfish genetic linkage and physical maps using BAC-anchored microsatellites. Name: Ninwichian, Parichart. Degree: PhD. Chair: Liu, Zhanjiang. Resides: FAA library. University: Auburn. Location: Auburn University. Date: 2012. Pages: 167. Keywords: Map integration; channel catfish; genetic linkage map; BES; physical map. Abstract: Integration of physical and linkage maps is a critical step in building necessary genome resources for fine mapping of QTL, comparative genomics, and accurate and efficient whole genome assembly. Previously, we have established both linkage maps and a physical map for channel catfish,. Ictalurus punctatus, the dominant aquaculture species in the U.S. Here we added 2,030 BAC-end sequence-derived microsatellites from 1,481 physical map contigs to a high-density ...
High density genetic linkage maps are important tools for QTL fine mapping, map-based cloning, comparative genome analysis and the integration of genetic and physical maps. Several genetic linkage maps based on various markers technologies are now available for perennial ryegrass [1-9]. These maps of moderate marker densities have proved valuable for mapping QTL to broad genome regions. Public marker resources recently established provide the opportunity to increase marker density of these maps, thereby improving map resolution [10-13].. For example, the genetic linkage map of the perennial ryegrass mapping population VrnA has initially been used for a QTL study to characterise vernalization response and contained 93 markers spanning 490.4 cM with an average distance between markers of 5 cM [2]. This map has been complemented over time with candidate gene-based CAPS markers to study disease ...
Background Genetic markers and linkage mapping are basic prerequisites for marker-assisted selection and map-based cloning. In the case of the key grassland species Lolium spp., numerous mapping populations have been developed and characterised for various traits. Although some genetic linkage maps of these populations have been aligned with each other using publicly available DNA markers, the number of common markers among genetic maps is still low, limiting the ability to compare candidate gene and QTL locations across germplasm. Results A set of 204 expressed sequence tag (EST)-derived simple sequence repeat (SSR) markers has been assigned to map positions using eight different ryegrass mapping populations. Marker properties of a subset of 64 EST-SSRs were assessed in six to eight individuals of each mapping population and revealed 83% of the markers to be polymorphic in at least one population and an average number of ...
The transmission disequilibrium test (TDT) was proposed by Spielman, McGinnis and Ewens (1993) as a family-based association test for the presence of genetic linkage between a genetic marker and a trait. It is an application of McNemars test. A specificity of the TDT is that it will detect genetic linkage only in the presence of genetic association. While genetic association can be caused by population structure, genetic linkage will not be affected, which makes the TDT robust to the presence of population structure. We first describe the TDT in the case where families consist of trios (two parents and one affected child). Our description follows the notations used in Spielman, McGinnis & Ewens (1993). The TDT measures the over-transmission of an allele from heterozygous parents to affected offsprings. The n affected offsprings have 2n parents. These can be ...
Late-onset Alzheimers disease (LOAD) is a common neurodegenerative disorder, with a complex etiology. APOE is the only confirmed susceptibility gene for LOAD. Others remain yet to be found. Evidence from linkage studies suggests that a gene (or genes) conferring susceptibility for LOAD resides on chromosome 10. We studied 23 positional/functional candidate genes from our linkage region on chromosome 10 (APBB1IP, ALOX5, AD037, SLC18A3, DKK1, ZWINT, ANK3, UBE2D1, CDC2, SIRT1, JDP1, NET7, SUPV3L1, NEN3, SAR1, SGPL1, SEC24C, CAMK2G, PP3CB, SNCG, CH25H, PLCE1, ANXV111) in the MRC genetic resource for LOAD. These candidates were screened for sequence polymorphisms in a sample of 14 LOAD subjects and detected polymorphisms tested for association with LOAD in a three-stage design involving two stages of genotyping pooled DNA samples followed by a third stage in which markers showing evidence for association in the first stages were subjected to individual ...
Vol 13: Genetic linkage maps for Asian and American lotus constructed using novel SSR markers derived from the genome of sequenced cultivar.. . 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.
Life history traits such as fecundity are important to evolution because they make up components of lifetime fitness. Due to their polygenic architectures, such traits are difficult to investigate with genetic mapping. Therefore, little is known about their molecular basis. One possible way toward finding the underlying genes is to map intermediary molecular phenotypes, such as gene expression traits. We set out to map candidate quantitative trait genes for egg fecundity in the chicken by combining quantitative trait locus mapping in an advanced intercross of wild by domestic chickens with expression quantitative trait locus mapping in the same birds. We measured individual egg fecundity in 232 intercross chickens in two consecutive trials, the second one aimed at measuring brooding. We found 12 loci for different aspects of egg fecundity. We then combined the genomic confidence intervals of these loci with expression quantitative trait loci from bone and hypothalamus in the same intercross. ...
Type 2 diabetes is a genetically heterogeneous disease involving insulin resistance, β-cell dysfunction, and increased glucose production by the liver. Identification of multiple QTLs suggests that there is a high degree of genetic heterogeneity of type 2 diabetes. To circumvent this limitation, we focused on a single large family, because those individuals likely share the same polymorphisms, thus minimizing genetic heterogeneity. Although environmental factors, such as physical activity and diet, also influence the development of type 2 diabetes and may interact with genetic effects, these measures were not collected, therefore future studies should further examine these effects.. Our results suggest that a gene located near D5S428 is responsible for variability in affection status. As we focused on a single family, the applicability of these findings to the general population is a concern. However, Lindsay et al. (29) identified tentative ...
We report a family with 15 individuals affected with multiple sclerosis present in three and possibly four generations. The segregation of multiple sclerosis within this pedigree is consistent with an autosomal dominant mode of inheritance with reduced penetrance. The clinical characteristics of the affected individuals are indistinguishable from those seen in sporadic multiple sclerosis with respect to sex ratio, age at onset, onset symptom, MRI and clinical course. Eleven of 14 cases (78.6%) were positive for the known multiple sclerosis-associated major histocompatibility complex (MHC) Class II HLA DRB1*15 allele. Parametric linkage analysis gave a non-significant LOD score of 0.31 (theta; = 0.33) for the DRB1 gene. However, among 11 affected children with at least one DRB1*15 bearing parent, all 11 out of 11 received at least one copy of this known susceptibility allele. A transmission disequilibrium test analysis was significant for the DRB1*15 allele within this single family; P = ...
Pinpointing genes involved in non-right-handedness has the potential to clarify developmental contributions to human brain lateralization. Major-gene models have been considered for human handedness which allow for phenocopy and reduced penetrance, i.e. an imperfect correspondence between genotype and phenotype. However, a recent genome-wide association scan did not detect any common polymorphisms with substantial genetic effects. Previous linkage studies in families have also not yielded significant findings. Genetic heterogeneity and/or polygenicity are therefore indicated, but it remains possible that relatively rare, or even unique, major-genetic effects may be detectable in certain extended families with many non-right-handed members. Here we applied whole exome sequencing to 17 members from a single, large consanguineous family from Pakistan. Multipoint linkage analysis across all autosomes did not yield clear ...
The present study was undertaken to identify genes that influence LDL size properties. Although LDL size phenotype has been shown in many studies to be an important CVD risk factor, little is known about the genes that influence LDL size properties. In this study, we used gradient gel electrophoresis to measure the amount of cholesterol in each of 4 different LDL size fractions, and performed mixing experiments to show that LDL particles that differed in size and composition have similar chromogenicities for cholesterol staining (Figure 1⇑). For each of the 4 LDL size fractions, we found significant heritabilities, which ranged from 22% to 37% (Table 1⇑), suggesting the existence of 1 or more genes that influence each of the 4 fractions. These measures of LDL size fractions were also significantly influenced by several covariates, including age and sex. The LDL size fractions are related metabolically36 and they are significantly intercorrelated phenotypically (r2 values for the 6 possible ...
Objective: To further confirm the association between two IRF6 single nucleotide polymorphisms and nonsyndromic cleft lip with or without cleft palate in a Chinese population.. Participants: A total of 106 nonsyndromic cleft lip with or without cleft palate case trios and 129 control trios.. Intervention: Two IRF6 single nucleotide polymorphisms, rs2235371 and rs642961, were genotyped for all case and control families. Case-control analysis and family-based linkage analysis were both performed for the two single nucleotide polymorphisms.. Results: The genotype and allele frequencies of rs2235371 (odds ratio(AG+AA) (vs. GG), 0.581; 95% confidence interval, 0.345 to 0.976; P < .039) and rs642961 (odds ratio(AG+AA vs. GG), 5.389; 95% confidence interval, 2.936 to 9.893; P = 5e-08) were significantly higher in nonsyndromic cleft lip with or without cleft palate patients compared with controls. There was an obvious dosage effect of allele A at rs642961. The transmission of a major allele (G) of ...
Introduction. Genetic linkage maps have been obtained for several plant species and are the basis for advanced genetic studies that provide a better understanding of the inheritance, identification and isolation of genes (Roose et al., 2000). Cloning and gene insertion through genetic transformation have been widely used in species with well-defined genetic maps (Gmitter Jr. et al., 1996).. Different types of molecular markers have been used to obtain genetic linkage maps. Molecular markers are used because they are highly polymorphic and are not influenced by the environment. Among these, random amplified polymorphic DNA (RAPD) markers are the most common because the technique is easy, inexpensive, uses a low amount of genomic DNA, and produces markers that are highly polymorphic and that represent the whole genome (Ferreira and Grattapaglia, 1998). RAPD markers are detected by the random ...
BACKGROUND: Age at onset of Huntingtons disease (HD) is correlated with the size of the abnormal CAG repeat expansion in the HD gene; however, several studies have indicated that other genetic factors also contribute to the variability in HD age at onset. To identify modifier genes, we recently reported a whole-genome scan in a sample of 629 affected sibling pairs from 295 pedigrees, in which six genomic regions provided suggestive evidence for quantitative trait loci (QTL), modifying age at onset in HD. METHODS: In order to test the replication of this finding, eighteen microsatellite markers, three from each of the six genomic regions, were genotyped in 102 newly recruited sibling pairs from 69 pedigrees, and data were analyzed, using a multipoint linkage variance component method, in the follow-up sample and the combined sample of 352 pedigrees with 753 sibling pairs. RESULTS: Suggestive evidence for linkage at 6q23-24 in the follow-up sample (LOD = 1.87, ...
Evidence for a rare prostate cancer-susceptibility locus at chromosome 1p36. In Swedish families with hereditary prostate cancer, linkage to the HPC1 (ital) locus on chromosome 1q24-25 is restricted to families with early-onset prostate cancer
Autosomal dominant optic atrophy (OPA, MIM 165500) is an eye disease characterised by variable optic atrophy and reduction in visual acuity. It has an insidious onset in the first decade of life and is clinically highly heterogeneous. It is associated with a centrocecal scotoma of varying size and density and an acquired blue-yellow dyschromatopsia. Recent studies of three large Danish pedigrees have mapped a gene for dominant optic atrophy (OPA1) to a 10 cM region on chromosome 3q, between markers D3S1314 and D3S1265 (3q28-qter). Genetic linkage analysis in five British pedigrees confirms mapping to chromosome 3q28-qter. Haplotype analysis of a seven generation pedigree positions the disease causing gene between loci D3S3590 and D3S1305, corresponding to a genetic distance of 2 cM. This represents a significant linkage refinement and should facilitate positional cloning of the disease gene.. ...
Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical characteristics of affected individuals for researchers interested in this valuable resource for genetic studies of OCD. The project clinically evaluated and collected blood specimens from 238 families containing 299 OCD-affected sibling pairs and their parents, and additional affected relative pairs, for a genome-wide linkage study. Of the 999 individuals interviewed to date, 624 were diagnosed with definite OCD. The mean age of subjects ...
Low fermentation temperatures are of importance to food and beverage industries working with Saccharomyces cerevisiae Therefore, the identification of genes demonstrating a positive impact on fermentation kinetics is of significant interest. A set of 121 mapped F1 progeny, derived from a cross between haploid strains BY4716 (a derivative of the laboratory yeast S288C) and wine yeast RM11-1a, were fermented in New Zealand Sauvignon Blanc grape juice at 12.5°. Analyses of five key fermentation kinetic parameters among the F1 progeny identified a quantitative trait locus (QTL) on chromosome I with a significant degree of linkage to maximal fermentation rate (Vmax) at low temperature. Independent deletions of two candidate genes within the region, FLO1 and SWH1, were constructed in the parental strains (with S288C representing BY4716). Fermentation of wild-type and deletion strains at 12.5 and 25° confirmed that the genetic linkage to Vmax corresponds to the ...
The development of array-based high-throughput genotyping methods created significant opportunities to increase the number of genetic populations for linkage analysis. In the present study, a strategy was proposed for mapping QTLs (quantitative trait loci) based on DArT (diversity arrays technology) genotyping system. A consensus linkage map was constructed with both DArT and SSR markers by utilizing a subgroup DH population, and a second linkage map was constructed with SSR markers alone and a more extensive full DH population. Resistance to barley net-type net blotch disease was analyzed using the subpopulation data with the high-density consensus linkage map and the full-population data with the low-density SSR linkage map, respectively. Two interactive QTLs were detected either by the sub- or full population. Simulation studies were conducted to validate the strategy presented in this chapter. In ...
Pure familial spastic paraplegias (FSP) are neurodegenerative disorders that are clinically characterized by progressive spasticity of the lower limbs and are inherited as autosomal dominant (DFSP) or autosomal recessive (RFSP) traits. The primary defect in FSP is unknown. Genetic linkage analysis was applied to five RFSP families from Tunisia. In four of these five families tight linkage of the RFSP locus was established to the chromosome 8 markers, D8S260, D8S166, D8S285, PLAT, and D8S279. The RFSP locus in the fifth family was not linked to these markers which provided evidence of genetic locus heterogeneity in RFSP. Identification of the RFSP gene on chromosome 8 will help in understanding the genetic factors in motor neuron degeneration.
Effective identification of disease-causing gene locations can have significant impact on patient management decisions that will ultimately increase survival rates and improve the overall quality of health care. Linkage disequilibrium mapping is the process of finding disease gene locations through comparisons of haplotype frequencies between disease chromosomes and normal chromosomes. This work presents a new method for linkage disequilibrium mapping. The main advantage of the proposed algorithm, called LinkageTracker, is its consistency in producing good predictive accuracy under different conditions, including extreme conditions where the occurrence of disease samples with the mutation of interest is very low and there is presence of error or noise. We compared our method with some leading methods in linkage disequilibrium mapping such as HapMiner, Blade, GeneRecon, and Haplotype Pattern Mining (HPM). Experimental results show that for a ...
We have previously found linkage to chromosome 1p34 in five large families with autosomal dominant non-syndromic hearing impairment (DFNA2). In all five families, the connexin31 gene (GJB3), located at 1p34 and responsible for non-syndromic autosomal dominant hearing loss in two small Chinese families, has been excluded as the responsible gene. Recently, a fourth member of the KCNQ branch of the K+ channel family, KCNQ4, has been cloned. KCNQ4 was mapped to chromosome 1 p34 and a single mutation was found in three patients from a small French family with non-syndromic autosomal dominant hearing loss. In this study, we have analysed the KCNQ4 gene for mutations in our five DFNA2 families. Missense mutations altering conserved amino acids were found in three families and an inactivating deletion was present in a fourth family. No KCNQ4 mutation could be found in a single DFNA2 family of Indonesian origin. These results indicate that at least two and possibly three genes responsible for hearing ...
Objective Autosomal recessive nonsyndromic hearing loss (ARNSHL) is a genetically heterogeneous sensorineural disorder. Alpha-tectorin, which is encoded by the TECTA gene, is a non-collagenous component of the tectorial membrane in the inner ear defect of which leads to moderate to severe hearing loss (HL). Methods 25 unrelated Iranian multiplex ARNSHL families, negative for GJB2 mutations, were recruited in this study. Clinical inspections including audiometric and otologic examinations ruled out syndromic forms. Genetic linkage analysis was performed using six short tandem repeat markers closely linked to DFNB21. Haplotype and LOD score analysis were used to confirm possible linkage. All coding exons of TECTA were subject to DNA sequencing in the linked family. Results A novel homozygous variant (c.734G , A) was found in exon 5 of the TECTA gene in one family leading to a nonsense mutation (p.W245×). It co-segregated with HL in the family. ...
All information about the latest scientific publications of the Clínica Universidad de Navarra. Upper digestive hemorrhage in a patient with von Recklinghausen neurofibromatosis
In this study, we identified and replicated TRAF1 (lead SNP rs2416804) on chromosome 9 to be linked and associated with CIMT (pooled P=6.02×10-7). We additionally identified 2 genomic regions on chromosomes 4 and 17 with suggestive linkage to CIMT, which have not been reported before. Finally, we could replicate previously reported linkage findings on chromosomes 13 and 14.. Our combined linkage and association analysis identified a SNP in TRAF1 on chromosome 9, as well as a cluster of SNPs on chromosome 6. TRAF proteins mediate the signal transduction from receptors of the tumor necrosis factor receptor and were detected in plaques from atherosclerotic lesions.31 A genome-wide association study and a candidate gene study identified TRAF1 as susceptibility genes for rheumatoid arthritis (RA).32,33 RA is associated with increased mortality, largely as a consequence of coronary artery disease. It was, thus, hypothesized that inflammation associated with RA ...
The observation that variants regulating gene expression (expression quantitative trait loci, eQTL) are at a high frequency among SNPs associated with complex traits has made the genome-wide characterization of gene expression an important tool in genetic mapping studies of such traits. As part of a study to identify genetic loci contributing to bipolar disorder and other quantitative traits in members of 26 pedigrees from Costa Rica and Colombia, we measured gene expression in lymphoblastoid cell lines derived from 786 pedigree members. The study design enabled us to comprehensively reconstruct the genetic regulatory network in these families, provide estimates of heritability, identify eQTL, evaluate missing heritability for the eQTL, and quantify the number of different alleles contributing to any given locus. In the eQTL analysis, we utilize a recently proposed hierarchical multiple testing strategy which controls error rates regarding ...
This paper investigates the effect of relevant physical parameters on transient temperature elevation induced in human tissues by electromagnetic waves in the terahertz (THz) band. The problem is defined by assuming a plane wave, which, during a limited time interval, normally impinges on the surface of a 3-layer model of the human body, causing a thermal transient. The electromagnetic equations are solved analytically, while the thermal ones are handled according to the finite element method. A parametric analysis is performed with the aim of identifying the contribution of each parameter, showing that the properties of the first skin layer (except blood flow) play a major role in the computation of the maximum temperature rise for the considered exposure situation. Final results, obtained by combining all relevant parameters together, show that the deviation from the reference solution of the maximum temperature elevation in skin is included in the coverage intervals from −30% to +10% at 0.1 ...
The combination of gene expression profiling with linkage analysis has become a powerful paradigm for mapping gene expression quantitative trait loci (eQTL). To date, most studies have searched for eQTL by analyzing gene expression traits one at a time. As thousands of expression traits are typically analyzed, this can reduce power because of the need to correct for the number of hypothesis tests performed. In addition, gene expression traits exhibit a complex correlation structure, which is ignored when analyzing traits individually. To address these issues, we applied two different multivariate dimension reduction techniques, the Singular Value Decomposition (SVD) and Independent Component Analysis (ICA) to gene expression traits derived from a cross between two strains of Saccharomyces cerevisiae. Both methods decompose the data into a set of meta-traits, which are linear combinations of all the expression traits. The meta-traits were enriched for several Gene Ontology categories ...
This work presents an energetic, exergoeconomic, environmental, and toxicity analysis of the simple gas turbine M501F3 based on a parametric analysis of energetic (thermal efficiency, fuel and air flow rates, and specific work output), exergoeconomic (exergetic efficiency and exergoeconomic operation costs), environmental (global warming, smog formation, acid rain indexes), and human toxicity indexes, by taking the compressor pressure ratio and the turbine inlet temperature as the operating parameters. The aim of this paper is to provide an integral, systematic, and powerful diagnostic tool to establish possible operation and maintenance actions to improve the gas turbines exergoeconomic, environmental, and human toxicity indexes. Despite the continuous changes in the price of natural gas, the compressor, combustion chamber, and turbine always contribute 18.96%, 53.02%, and 28%, respectively, to the gas turbines exergoeconomic operation costs. The application of this methodology can be extended to
The whitebacked planthopper (WBPH), Sogatella furcifera Horváth, is a serious rice pest in Asia. Ovicidal resistance is a natural rice defense mechanism against WBPH and is characterized by the formation of watery lesions (WLs) and increased egg mortality (EM) at the WBPH oviposition sites. This study aimed to understand the genetic and molecular basis of rice ovicidal resistance to WBPH by combining genetic and genomic analyses. First, the ovicidal trait in doubled haploid rice lines derived from a WBPH-resistant cultivar (CJ06) and a WBPH-susceptible cultivar (TN1) were phenotyped based on the necrotic symptoms of the leaf sheaths and EM. Using a constructed molecular linkage map, 19 quantitative trait loci (QTLs) associated with WLs and EM were identified on eight chromosomes. Of them, qWL6 was determined to be a major QTL for WL. Based on chromosome segment substitution lines and a residual heterozygous population, a high-resolution ...
This study shows that elevated LDL cholesterol levels in a Utah kindred, indicative of clinical FH, are linked to a region on chromosome 1p32. We have previously shown that this pedigree is clearly not linked to the LDL receptor or apo B gene,8 and additional markers near each gene in this study confirm the absence of linkage. A gene within a 17-cM region on chromosome 1 appears to be the major determinant of the observed elevated LDL cholesterol. There may be additional genes with minor effects on LDL cholesterol levels on chromosomes 3 and 17 in this pedigree. The LDL cholesterol levels of this pedigree are similar to those of FH pedigrees with known LDL receptor mutations, and penetrance is complete even at young ages. Triglyceride levels are significantly lower than in FH pedigrees, but mean age and body mass index are also lower. There were no differences in the frequency of tendon xanthomas. Therefore, genotyping to determine linkage or the presence of ...
Looking for online definition of agammaglobulinaemia in the Medical Dictionary? agammaglobulinaemia explanation free. What is agammaglobulinaemia? Meaning of agammaglobulinaemia medical term. What does agammaglobulinaemia mean?
Field resistance to cyst nematode (SCN) race 3 (Heterodera glycines I.) in soybean [Glycine max (L.) Merr.] cv Forrest is conditioned by two QTLs: the underlying genes are presumed to include Rhg1 on linkage group G and Rhg4 on linkage group A2. A population of recombinant inbred lines (RILs) and two populations of near-isogenic lines (NILs) derived from a cross of Forrest × Essex were used to map the loci affecting resistance to SCN. Bulked segregant analysis, with 512 AFLP primer combinations and microsatellite markers, produced a high-density genetic map for the intervals carrying Rhg1 and Rhg4. The two QTLs involved in resistance to SCN were strongly associated with the AFLP marker EATGMCGA87 (P = 0.0001, R2 = 24.5%) on linkage group G, and the AFLP marker ECCGMAAC405 (P = 0.0001, R2 = 26.2%) on linkage group A2. Two-way analysis of variance showed epistasic interaction (P = 0.0001, R2 =16%) between the two loci ...
Allelic association methods based on increased transmission of marker alleles will have to be employed for the mapping of complex disease susceptibility genes. However, because the extent of association of single marker alleles with disease is a function of the relative frequency of the allele on disease-associated chromosomes versus non disease-predisposing chromosomes, the most associated marker allele in a region will not necessarily be closest to the disease locus. To overcome this problem we describe a haplotype-based approach developed for mapping of the putative type 1 diabetes susceptibility gene IDDM6. Ten microsatellite markers spanning a 550 kb segment of chromosome 18q21 in the putative IDDM6 region were genotyped in 1708 type 1 diabetic Caucasian families from seven countries. The most likely ancestral diabetogenic chromosome was reconstructed in a step-wise fashion by analysing linkage disequilibrium between a previously defined haplotype of three adjacent ...
Congenital cataract, although uncommon, accounts for about 10% of childhood blindness.1 The cataract is usually seen as an isolated abnormality but may occur in association with other ocular developmental or systemic abnormalities. About 50% of bilateral cases have a genetic basis. Congenital cataract is both clinically and genetically heterogeneous; isolated congenital cataract is usually inherited as an autosomal dominant trait although autosomal recessive and X linked inheritance are seen less commonly.2 Most progress has been made in identifying the genes causing autosomal dominant congenital cataract.2 Two main approaches have been used to identify the causative mutations. In large families linkage analysis has been used to identify the chromosomal locus followed by screening of positional candidate genes; most genes have been identified using this strategy. A second approach has been to screen DNA from large panels of patients with inherited cataract ...
The SNP rs398652 on 14q21 and several other promising genetic variants were associated in our GWAS with telomere length in leukocytes. We then found that rs398652 was also associated with reduced bladder cancer risk. This SNP is located within the region of 14q that has a high linkage with leukocyte telomere length and is fewer than 450 kb from a microsatellite marker (D14S285) shown to have a very high logarithm (base 10) of odds (LOD) of approximately 3.5 for linkage with telomere length in a previous genetic linkage analysis (27). Furthermore, our mediation analysis to dissect the relationship between rs398652, telomere length, and bladder cancer risk suggests that the association of this SNP with bladder cancer is partially mediated by telomere length.. Telomere shortening and telomerase activation are critical early events of tumorigenesis. Results from a number of epidemiologic studies suggest that shorter telomere ...
Obesity is a complex phenotype affected by genetic and environmental influences such as sociocultural factors and individual behaviors. Previously, we performed two separate genome-wide investigations for adiposity-related traits (BMI, percentage body fat (%BF), abdominal circumference (ABDCIR), and serum leptin and serum adiponectin levels) in families from American Samoa and in families from Samoa. The two polities have a common evolutionary history but have lately been influenced by variations in economic development, leading to differences in income and wealth and in dietary and physical activity patterns. We now present a genome-wide linkage scan of the combined samples from the two polities. We adjust for environmental covariates, including polity of residence, education, cigarette smoking, and farm work, and use variance component methods to calculate univariate and bivariate multipoint lod scores. We identified a region on 9p22 with genome-wide significant ...
We previously reported genome-wide significant evidence for linkage between chromosome 6q and bipolar I disorder (BPI) by performing a meta-analysis of original genotype data from 11 genome scan linkage studies. We now present follow-up linkage disequilibrium mapping of the linked region utilizing 3,047 single nucleotide polymorphism (SNP) markers in a case-control sample (N = 530 cases, 534 controls) and family-based sample (N = 256 nuclear families, 1,301 individuals). The strongest single SNP result (rs6938431, P = 6.72 x 10(-5)) was observed in the case-control sample, near the solute carrier family 22, member 16 gene (SLC22A16). In a replication study, we genotyped 151 SNPs in an independent sample (N = 622 cases, 1,181 controls) and observed further evidence of association between variants at SLC22A16 and BPI. Although consistent evidence of association with any single variant was not seen across samples, SNP-wise and gene-based test results in the ...
Results The results of exclusion analyses suggested that family PKRP173 was linked to chromosome 2q harbouring mer tyrosine kinase protooncogene (MERTK), a gene previously associated with autosomal recessive RP. Additional STR markers refined the critical interval and placed it in a 13.4 cM (17 Mb) region flanked by D2S293 proximally and D2S347 distally. Significant logarithm of odds (LOD) scores of 3.2, 3.25 and 3.18 at θ=0 were obtained with markers D2S1896, D2S2269 and D2S160. Sequencing of the coding exons of MERTK identified a mutation, c.718G→T in exon 4, which results in a premature termination of p.E240X that segregates with the disease phenotype in the family. ...
IN the mapping of quantitative trait loci (QTL) in an experimental cross, selective genotyping (in which only the individuals at the extremes of the phenotype distribution are genotyped) can provide nearly equivalent power to complete genotyping at a reduced cost (Lander and Botstein 1989; Darvasi and Soller 1992).. Interval mapping with selectively genotyped data is best performed with consideration of all individuals, even those that were not genotyped (Lander and Botstein 1989). Consideration of only the genotyped individuals results in a biased estimate of the QTL effect. Haley-Knott regression (Haley and Knott 1992) generally provides a good approximation to standard interval mapping, but should be avoided in the case of selective genotyping, as it tends to produce inflated evidence for linkage (Feenstra et al. 2006).. Despite the common use of selective genotyping for QTL mapping and the extensive literature on significance thresholds for QTL mapping, we are not aware of any discussion ...
Four intragenic polymorphic microsatellite markers, AAAT Alu repeat, IVS27AC28.4, ACI27.2, and IVS38GT53.0, located along a 65 kb DNA region of the NF1 gene, were used to genotype 64 Spanish families with neurofibromatosis type 1 (NF1). Linkage disequilirium between each pair of markers was evaluated. Three of these markers, AAAT Alu repeat, ACI27.2, and IVS38GT53.0, exhibit linkage disequilibrium between each other. Analysis of extended haplotypes provides further evidence of the disequilibrium within this region since only 11 haplotypes account for 52% of the total chromosomes. Because of linkage disequilibrium, the informativeness of marker combinations for genotyping of NF1 families is diminished. There was no difference in the overall distribution of alleles between affected and normal chromosomes. An at risk haplotype was not found, as expected for a disease with at least 50% of cases being sporadic.. ...
X-linked agammaglobulinemia (XLA) is a rare genetic disorder discovered in 1952 that affects the bodys ability to fight infection. As the form of agammaglobulinemia that is X-linked, it is much more common in males. In people with XLA, the white blood cell formation process does not generate mature B cells, which manifests as a complete or near-complete lack of proteins called gamma globulins, including antibodies, in their bloodstream. B cells are part of the immune system and normally manufacture antibodies (also called immunoglobulins), which defend the body from infections by sustaining a humoral immunity response. Patients with untreated XLA are prone to develop serious and even fatal infections. A mutation occurs at the Brutons tyrosine kinase (Btk) gene that leads to a severe block in B cell development (at the pre-B cell to immature B cell stage) and a reduced immunoglobulin production in the serum. Btk is particularly responsible for mediating B cell development and maturation ...
Prostate cancer (PrCa) is the most frequently diagnosed cancer in males in developed countries. To identify common PrCa susceptibility alleles, we previously conducted a genome-wide association study in which 541,129 SNPs were genotyped in 1,854 PrCa cases with clinically detected disease and in 1,894 controls. We have now extended the study to evaluate promising associations in a second stage in which we genotyped 43,671 SNPs in 3,650 PrCa cases and 3,940 controls and in a third stage involving an additional 16,229 cases and 14,821 controls from 21 studies. In addition to replicating previous associations, we identified seven new prostate cancer susceptibility loci on chromosomes 2, 4, 8, 11 and 22 (with P = 1.6 x 10(-8) to P = 2.7 x 10(-33)).
A collection of disease information resources and questions answered by our Genetic and Rare Diseases Information Specialists for Autosomal dominant medullary cystic kidney disease with hyperuricemia
By exploiting the resources generated by the Arabidopsis genome project in a targeted comparative mapping study, we constructed high-resolution physical maps of a 510-kb chromosomal region that encompasses the S locus in B. campestris and of a 275-kb homeologous region in Arabidopsis. The value of comparative mapping for traits that are unique to one of the two species being compared has been questioned (Van Deynze et al., 1995). However, in our study, the comparative mapping approach was clearly useful, despite the fact that Arabidopsis lacks a functional SI system.. The close physical and genetic linkage of the ETR1 marker to the Brassica S locus identifies the Brassica homolog of this well-characterized Arabidopsis gene and its map position, and it provides a clear landmark for the genomic location of the S locus. Furthermore, due to the synteny exhibited by the two homeologous regions on a submegabase scale, the comparative study generated several molecular markers for ...
A unique sutural cataract was observed in a 4-generation German family to be transmitted as an isolated autosomal, dominant trait. Since mutations in the gamma-crystallin encoding CRYG genes have previously been demonstrated to be the most frequent reason for isolated congenital cataracts, all 4 active CRYG genes have been sequenced. A single base-pair change in the CRYGA gene has been shown, leading to a premature stop codon. This was not observed in 170 control individuals. However, it did not segregate with the disease phenotype. This is the first truncating mutation in an active CRYG gene without a dominant phenotype. As the CRYGA mutation did not explain the cataract, several other candidate loci (CCV, GJA8, CRYBB2, BFSP2, MIP, GJA8, central pouch-like, CRYBA1) were investigated by micro-satellite markers and linkage analysis, but they were excluded based on the combination of haplotype analysis and two-point linkage analysis. The phenotype in this family is due to a ...
We performed linkage analysis to map the locus of familial moyamoya disease on chromosome 17. Despite the small pedigree and the limited number of microsatellite markers on chromosome 17, we successfully identified the disease locus in the telomeric region of the long arm of chromosome 17. With the APM method, we confirmed the linkage at a significantly low P value. During the initial period of this study, we expected moyamoya disease to be related to the NF1 gene located on chromosome 17q11.2. The NF1 protein is a GTPase-activating protein that regulates cellular growth through control of the Ras oncogene. We hypothesized that aberration of this regulation might give rise to the proliferation of endothelial and smooth muscle cells in the internal carotid arteries and their branches. The present data, however, did not support the direct participation of the NF1 gene in the occurrence of moyamoya disease and instead indicated the importance of a distinct gene located closer ...
TY - JOUR. T1 - Inherited, familial and sporadic primary open-angle glaucoma. AU - Gong, Gordon. AU - Kosoko-Lasaki, Sade. AU - Haynatzki, Gleb. AU - Lynch, Henry T.. AU - Lynch, Jane A.. AU - Wilson, M. Roy. PY - 2007/5/1. Y1 - 2007/5/1. N2 - The U.S. surgeon general has recently launched a campaign to promote the awareness of the medical value of family history. Further attention should be paid to familial aggregation. Accordingly, we suggest that primary open-angle glaucoma (POAG) be classified into inherited, familial and sporadic categories. The three classes of POAG differ not only in inheritance pattern and familial aggregation but also in methodology and outcome of gene mapping. Inherited POAG follows Mendelian inheritance and has been linked to seven chromosomal loci to date by linkage analysis. Familial POAG does not show a clear pattern of Mendelian inheritance and is typically studied by sib-pair analysis and family-based association analysis, although the results often require ...
Previous studies have identified multiple loci on 8q24 associated with prostate cancer risk. We performed a comprehensive analysis of SNP associations across 8q24 by genotyping tag SNPs in 5,504 prostate cancer cases and 5,834 controls. We confirmed associations at three previously reported loci and identified additional loci in two other linkage disequilibrium blocks (rs1006908: per-allele OR = 0.87, P = 7.9 x 10(-8); rs620861: OR = 0.90, P = 4.8 x 10(-8)). Eight SNPs in five linkage disequilibrium blocks were independently associated with prostate cancer susceptibility.
The identification of informative in silico polymorphic genomic and genic microsatellite markers by comparing the genome and transcriptome sequences of crop genotypes is a rapid, cost-effective and non-laborious approach for large-scale marker validation and genotyping applications, including construction of high-density genetic maps. We designed 1494 markers, including 1016 genomic and 478 transcript-derived microsatellite markers showing in-silico fragment length polymorphism between two parental genotypes (Cicer arietinum ICC4958 and C. reticulatum PI489777) of an inter-specific reference mapping population. High amplification efficiency (87%), experimental validation success rate (81%) and polymorphic potential (55%) of these microsatellite markers suggest their effective use in various applications of chickpea genetics and breeding. Intra-specific polymorphic potential (48%) detected by microsatellite markers in 22 desi and kabuli chickpea genotypes was lower than ...
TY - JOUR. T1 - Linkage of the Indiana kindred of gerstmann-sträussler-scheinker disease to the prion protein gene. AU - Dlouhy, Stephen R.. AU - Hsiao, Karen. AU - Farlow, Martin R.. AU - Foroud, Tatiana. AU - Conneally, P. Michael. AU - Johnson, Patricia. AU - Prusiner, Stanley B.. AU - Hodes, M. E.. AU - Ghetti, Bernardino. PY - 1992/4. Y1 - 1992/4. N2 - The Indiana kindred variant of Gerstmann-Sträussler-Scheinker disease has amyloid plaques that contain prion protein (PrP), but is atypical because neurofibrillary tangles like those of Alzheimer disease are present. To map the position of the disease causing gene, we used three markers for linkage analyses. A missense mutation at codon 198 of the PrP gene (PRNP) is found in all definitely affected individuals and yields a maximum lod score of 6.37 (θ= 0). The disease also is concordant with the two other PRNP-region markers. These results demonstrate tight linkage of the disease-causing gene to PRNP and ...
Abstract: : Purpose: To use data from a single large kindred to characterize the phenotype and map the gene responsible for autosomal dominant congenital cataract and microphthalmos with associated secondary glaucoma. Methods: A pedigree was constructed through interviews with the proband and his spouse. We performed ophthalmologic evaluations and obtained blood samples for linkage analysis from the proband, his wife and all 13 of their children. The presence of more than 11 informative meioses in this consanguineous family suggests that it could be useful in a linkage study. Results: The pedigree reveals three consanguineous matings including the proband and his wife; they have a kinship coefficient of 1/12 indicating that they have 17% of their genes in common (in comparison, siblings have 50% of their genes in common and first cousins have 6% of their genes in common). The proband and 9/13 children are affected with microphthalmia and congenital cataract. The proband and ...
Three quantitative trait loci (QTL) located on chromosome 1H, single QTL located on chromosomes 1H, 2H, 4H, 5H and 7H, were identified to be responsible for salinity tolerance under different environments. Waterlogging stress, daylight length and temperature showed significant effects on barley salinity tolerance. The QTL for salinity tolerance mapped on chromosomes 4H and 7H, QSlwd.YG.4H, QSlwd.YG.7H and QSlww.YG.7H were only identified in winter trials, while the QTL on chromosome 2H QSlsd.YG.2H and QSlsw.YG.2H were only detected in summer trials. Genes associated with flowering time were found to pose significant effects on the salinity QTL mapped on chromosomes 2H and 5H in summer trials. Given the fact that the QTL for salinity tolerance QSlsd.YG.1H and QSlww.YG.1H-1 reported here have never been considered in the literature, this warrants further investigation and evaluation for suitability to be used in breeding programs.. ...
The genetic architecture of crop domestication is generally characterized by three trends: relatively few genomic regions with major QTL effects are involved, QTL are often clustered, and alleles derived from the crop do not always contribute to the crop phenotype. We have investigated the genetic architecture of lettuce using a recombinant inbred line population from a cross between a crop Lactuca sativa (Salinas) and its wild relative L. serriola. Few genomic regions with major QTL, plus various intermediate QTL, largely control the transition from wild to cultivated Crisphead lettuce. Allelic effects of all major QTL were in the expected direction, but there were intermediate QTL where the crop contributed to the wild phenotype and vice versa. We found two main regions with clusters of QTL, one on linkage group 3, where the crop allele induced lower seed output, another on linkage group 7, where the crop allele caused a delay in flowering ...
Abnormalities in sleep and circadian rhythms are central features of bipolar disorder (BP), often persisting between episodes. We report here, to our knowledge, the first systematic analysis of circadian rhythm activity in pedigrees segregating severe BP (BP-I). By analyzing actigraphy data obtained from members of 26 Costa Rican and Colombian pedigrees [136 euthymic (i.e., interepisode) BP-I individuals and 422 non-BP-I relatives], we delineated 73 phenotypes, of which 49 demonstrated significant heritability and 13 showed significant trait-like association with BP-I. All BP-I-associated traits related to activity level, with BP-I individuals consistently demonstrating lower activity levels than their non-BP-I relatives. We analyzed all 49 heritable phenotypes using genetic linkage analysis, with special emphasis on phenotypes judged to have the strongest impact on the biology underlying BP. We identified a locus for interdaily stability of activity, at a threshold ...
Familial dilated cardiomyopathy (DCM) is genetically heterogeneous. Mutations in more than 40 genes have been identified in familial cases, mostly inherited in an autosomal dominant pattern. DCM due to recessive mutations is rarely observed. In consanguineous families, homozygosity mapping and whole exome sequencing (WES) can be utilized to identify the genetic defects in recessively inherited DCM. In a consanguineous family with four affected siblings with severe DCM, we combined homozygosity mapping, linkage analysis and WES, to uncover the genetic defect. A region of homozygosity (ROH) on chromosome 8q24.13-24.23 was found to be shared by all of the four affected siblings. WES detected ~47,000 variants that were filtered to a homozygous mutation (p.Gly243Arg) in the FBXO32 gene, located within the identified ROH. The mutation segregated with the phenotype, replaced a highly-conserved amino acid, and was not detected in 1986 ...
WNT7A encodes a secreted protein that stimulates LMX-1 to confer dorsal patterning in the developing limb ectoderm [18]. The linkage findings of Dietz et al. [15] suggested WNT7A as a highly plausible candidate gene for CTEV. They used seven markers around WNT7A on chromosome 3 in a linkage study of a single large family. Marker D3S3608, about 0.16 Mb away from WNT7A, gave the highest LOD score of 2.18. We used one marker intragenic to WNT7A, one downstream, and one D3S2403 upstream of D3S3608 to ensure that the region surrounding D3S3608 was excluded. This marker also allowed us to exclude linkage to a gene upstream of WNT7A expressed in skeleton, FIBULIN 2. We found no evidence for linkage to any of these markers in this large study, and thus we have shown that variation in either WNT7A or FIBULIN 2 is very unlikely to be significant causes of familial CTEV.. Samples from the 91 families studied represented 168 affected, and 92 unaffected ...
Relief is when you and the right researcher find each other Finding the right clinical trial for X-linked agammaglobulinemia with growth hormone deficiency can be challenging. However, with TrialsFinder (which uses the Reg4ALL database and privacy controls by Private Access), you can permit researchers to let you know opportunities to consider - all without revealing your identity. ...
Among all cereals, rice is highly sensitive to cold stress, especially at the germination stage, which adversely impacts its germination ability, seed vigor, crop stand establishment, and, ultimately, grain yield. The dissection of novel quantitative trait loci (QTLs) or genes conferring a low-temperature germination (LTG) ability can significantly accelerate cold-tolerant rice breeding to ensure the wide application of rice cultivation through the direct seeding method. In this study, we identified 11 QTLs for LTG using 144 recombinant inbred lines (RILs) derived from a cross between a cold-tolerant variety, Lijiangxintuanheigu (LTH), and a cold-sensitive variety, Shennong265 (SN265). By resequencing two parents and RIL lines, a high-density bin map, including 2,828 bin markers, was constructed using 123,859 single-nucleotide polymorphisms (SNPs) between two parents. The total genetic distance corresponding to all 12 chromosome linkage maps was 2,840.12 cm. Adjacent markers ...
A five generation family with an X linked ocular disorder has been investigated. The major clinical features were reduced visual acuity, nystagmus, and myopia. Although impaired night vision was not a symptom, using psychophysical and electrophysiological testing both rod and cone function were found to be abnormal in all affected males. No abnormality was detected in carrier females. Gene location studies showed X linked transmission of a gene that maps to proximal Xp11. The findings observed in this cohort are similar to those previously reported in both congenital stationary night blindness type 2 (CSNB2) and Aland Island eye disease (AIED). This study addresses whether CSNB2 and AIED are a single entity or whether the latter is a subset of the former.
The human Xp/Yp telomere-junction region exhibits high levels of sequence polymorphism and linkage disequilibrium. To determine whether this is a general feature of human telomeres, we have undertaken sequence analysis at the 12q telomere and have extended the analysis at Xp/Yp. A total of 22 single-nucleotide polymorphisms (SNPs) and one 30-bp duplication were detected in the 1,870 bp adjacent to the 12q telomere. Twenty polymorphic positions were in almost complete linkage disequilibrium, creating three common diverged haplotypes accounting for 80% of 12q telomeres in the white population. A further 6% of 12q telomeres contained a 1,439-bp deletion in the DNA flanking the telomere. The remaining 13% of 12q telomeres did not amplify with the primers used (nulls). The distribution of telomere (TTAGGG) and variant repeats within 12q telomeres was hypervariable, but alleles with similar distribution patterns were associated with the same haplotype in the telomere-adjacent DNA. ...
BACKGROUND:. There is family aggregation of obstructive sleep apnea (OSA) as has been shown in the United States, Europe and recently in Iceland. Iceland represents a unique opportunity for genetic research. It is a community that was settled by founders in the 9 th Century, and has developed in relative isolation since that time to its present size of 285,000 persons. Moreover, there is a commitment to record keeping that has allowed deCODE Genetics, who are collaborators on this grant, to develop a computerized genealogy data base that permits the ancestry of individuals to be traced over centuries. This tool, together with the founder nature of the population, makes possible a unique genealogy-driven approach to study the genetics of complex disorders, an approach that has already been successful.. DESIGN NARRATIVE:. The study uses patients with obstructive sleep apnea, who have already been diagnosed in Iceland where large family pedigrees have been ...
purpose. The genetic bases of Duanes retraction syndrome (DRS) were investigated to determine its molecular etiologies. In prior studies, the transcription factors SALL4 and HOXA1 were identified as the genes mutated in DRS with radial anomalies, and in DRS with deafness, vascular anomalies, and cognitive deficits, respectively. Less is known, however, about the genetic etiology of DRS when it occurs in isolation, and only one genetic locus for isolated DRS, the DURS2 locus on chromosome 2, has been mapped to date. Toward the goal of identifying the DURS2 gene, two pedigrees have been ascertained that segregate DRS as a dominant trait.. methods. Members of two large dominant DRS pedigrees were enrolled in an ongoing study of the genetic basis of the congenital cranial dysinnervation disorders, and linkage analysis was conducted to determine whether their DRS phenotype maps to the DURS2 locus.. results. By haplotype analysis, ...
Microsatellite markers from a transcriptome sequence library were initially isolated, and their genetic variation was characterized in a wild population of the mud crab (Scylla paramamosain). We then tested the association between these microsatellite markers and the growth performance of S. paramamosain. A total of 129 polymorphic microsatellite markers were identified, with an observed heterozygosity ranging from 0.19 to 1.00 per locus, an expected heterozygosity ranging from 0.23 to 0.96 per locus, and a polymorphism information content (PIC) ranging from 0.21 to 0.95 per locus. Of these microsatellite markers, 30 showed polymorphism in 96 full-sib individuals of a first generation family. Statistical analysis indicated that three microsatellite markers were significantly associated with 12 growth traits of S. paramamosain. Of these three markers, locus Scpa36 was significantly associated with eight growth traits, namely, carapace length, abdomen width (AW), body height (BH), fixed finger ...
Differences in floral morphologies affect pollination behaviour in many flowering plants. In the genus Oryza, several differences in the size of floral organs are known. In this study, we focused on the differences in the size of floral organs between common cultivated rice, Oryza sativa L. and its wild ancestor, O. rufipogon. We compared floral morphologies between cultivated rice O. sativa cv. Nipponbare and O. rufipogon W630. We first evaluated temporal changes in filament and anther lengths. W630 had longer filaments with rapid elongation within 15 min after spikelet opening. W630 also had longer anthers than Nipponbare, and size of anther was consistent throughout all time examined. We also analysed other six floral traits, and found that W630 had higher stigma and style length, as well as lemma and palea length, but lower lemma and palea width. Quantitative trait locus (QTL) analysis was performed to identify the loci controlling these floral traits, using backcross recombinant inbred

Genetic linkage - WikipediaGenetic linkage - Wikipedia

The greater the frequency of recombination (segregation) between two genetic markers, the further apart they are assumed to be ... Recombination frequency is a measure of genetic linkage and is used in the creation of a genetic linkage map. Recombination ... Thus, the use of recombination frequencies has been used to develop linkage maps or genetic maps. However, it is important to ... the recombination frequency is 50% since 2 of the 4 gametes were recombinant gametes. The recombination frequency will be 50% ...
more infohttps://en.wikipedia.org/wiki/Genetic_linkage

Patent US7893325 - Brassica plant resistant to the fungus Leptosphaeria maculans (blackleg) - Google PatentsPatent US7893325 - Brassica plant resistant to the fungus Leptosphaeria maculans (blackleg) - Google Patents

Genetic distance (map distance) is calculated from recombination frequencies and is expressed in centiMorgans (cM) [Kosambi ( ... The pairwise recombination frequencies between markers within a linkage group were calculated using default parameters of ... A molecular marker is said to be "linked" to a gene or locus, if the marker and the gene or locus have a greater association in ... "Linkage" refers to the genetic distance of the marker to the locus (or two loci or two markers to each other). The closer the ...
more infohttp://www.google.com/patents/US7893325?dq=7143430

Complete linkage - WikipediaComplete linkage - Wikipedia

Through recombination, daughter cells have the greatest amount of genetic diversity. (Click Here for a video tutorial ... A centimorgan is equivalent to the percent of recombination. two loci with 2% recombination frequency are located 2 ... In the absence of recombination, only parental phenotypes are expected. Genetic Linkage is the tendency of alleles, which are ... This process is known as genetic recombination. The rate of recombination of two discrete loci corresponds to their physical ...
more infohttps://en.wikipedia.org/wiki/Complete_linkage

Patent US5985549 - Non-isotopic in-situ hybridization method for detection of nucleic acids - Google PatentsPatent US5985549 - Non-isotopic in-situ hybridization method for detection of nucleic acids - Google Patents

... and computerized statistical approaches to determine genetic recombination frequencies as a measure of gene linkage (Botstein ... 6E and 6F). Greater than 70% of metaphase spreads were labelled with either the Y/H or the K probe, and generally both sister ... linkage may be evaluated as a continuum encompassing both the distances approachable by genetic recombination analysis ( ... In situations where the defect is an access of normal genetic material rather than aberrant genetic material, in-situ ...
more infohttp://www.google.com/patents/US5985549?dq=5,072,412

Highly Recombinogenic Regions at Seed Storage Protein Loci on Chromosome 1DS of Aegilops tauschii, the D-Genome Donor of Wheat ...Highly Recombinogenic Regions at Seed Storage Protein Loci on Chromosome 1DS of Aegilops tauschii, the D-Genome Donor of Wheat ...

... facilitating the construction of genetic linkage maps. Recombination frequency within a given genetic interval may also ... Tightly linked markers located on separate BAC clones may indicate that the corresponding physical/genetic distance was greater ... combined with genetic linkage maps of Ae. tauschii, is being used to investigate the relationship between genetic and physical ... 1991 A genetic linkage map of Triticum tauschii (DD) and its relationship to the D-genome of bread wheat (AABBDD). Genome 14: ...
more infohttp://www.genetics.org/content/155/1/361

Genetic hitchhiking - WikipediaGenetic hitchhiking - Wikipedia

Genetic draft generates a different allele frequency spectrum to genetic drift. The Y chromosome does not undergo recombination ... A greater distance would increase the chance of recombination separating M from A*, leaving M alone with any deleterious ... any other nearby polymorphisms that are in linkage disequilibrium will tend to change their allele frequencies too. Selective ... Genetic hitchhiking, also called genetic draft or the hitchhiking effect, is when an allele changes frequency not because it ...
more infohttps://en.wikipedia.org/wiki/Genetic_hitchhiking

Ancient Swedes were lactose intolerantAncient 'Swedes' were 'lactose intolerant'

In other words, recombination hasnt chopped up correlations of genetic variants along DNA strands. As you know this implies ... The region of the world where lactase persistence is at highest frequency and greatest extent is northern Europe. It turns out ... has an enormous region of linkage disequilibrium around it. ... Adoption and twin studies have shown it is mostly genetic.. ... We conclude that this difference in frequency could not have arisen by genetic drift and is either due to selection or, more ...
more infohttp://blogs.discovermagazine.com/gnxp/2010/04/ancient-swedes-were-lactose-intolerant/

Reference list for linkage map data from Variation in recombination frequency and distribution across eukaryotes: patterns and...Reference list for linkage map data from Variation in recombination frequency and distribution across eukaryotes: patterns and...

Reference list for linkage map data from Variation in recombination frequency and distribution across eukaryotes: patterns and ... There has been great progress in determining the molecular mechanisms governing recombination, and with the continued ... We discuss how variation in rate and distribution relates to genome architecture, genetic and epigenetic mechanisms, sex, ... Reference list for linkage map data from Variation in recombination frequency and distribution across eukaryotes: patterns and ...
more infohttps://figshare.com/articles/Reference_list_for_linkage_map_data_from_Variation_in_recombination_frequency_and_distribution_across_eukaryotes_patterns_and_processes/5589769/1

A Scan for Linkage Disequilibrium Across the Human Genome | GeneticsA Scan for Linkage Disequilibrium Across the Human Genome | Genetics

... based on the recombination linkage map; the y-axis shows the χ2 with 1 d.f. for the probability of the observed or greater LD ... 1997 Genetic variability and linkage disequilibrium within the DP region in the CEPH families. Hum. Immunol. 58: 112-121. ... Relationship between LD and recombination distance. (a) Histogram showing frequency (percentage) of locus pairs with small LDp ... 1969 Linkage disequilibrium at steady state determined by random genetic drift and recurrent mutation. Genetics 63: 229-238. ...
more infohttp://www.genetics.org/content/152/4/1711?ijkey=3025a2764e4e6b3bce1649a5831a4e964dc2bfcc&keytype2=tf_ipsecsha

homework - A Genetic linkage problem - Biology Stack Exchangehomework - A Genetic linkage problem - Biology Stack Exchange

recombination frequency problem. 3. What is the genetic distance where linkage can be ignored? ... Genetic linkage greater than 50 centimorgans. 1. Genetic mapping problem. 4. Is complete genetic linkage possible? ... Browse other questions tagged genetics homework recombination genetic-linkage or ask your own question. ... a) Find the number of linkage groups? b) Construct possible genetic map showing relative positions of these genes? ...
more infohttps://biology.stackexchange.com/questions/20452/a-genetic-linkage-problem

Phylogenetic relationships among domesticated and wild species of Cucurbita (Cucurbitaceae) inferred from a mitochondrial gene:...Phylogenetic relationships among domesticated and wild species of Cucurbita (Cucurbitaceae) inferred from a mitochondrial gene:...

This method detects recombination by considering the correlation between linkage disequilibrium (expressed as r2) and distance ... and distances excluding sites with alleles segregating at frequencies greater than 0.05 and 0.01. ... The close genetic relationship between C. pepo subsp. pepo and the Mexican wild species C. pepo subsp. fraterna indicated by ... linkage disequilibrium analyses to test for recombination across this region, (ii) analysis of molecular variance to determine ...
more infohttp://www.pnas.org/content/99/1/535.full

GENETIC EPIDEMIOLOGY GLOSSARY [M.Tevfik DORAK]GENETIC EPIDEMIOLOGY GLOSSARY [M.Tevfik DORAK]

... at the tip of the short arms has very high recombination frequency (the sex-averaged recombination frequency is 28% which, for ... See exercises on Gametes under Linkage and Linkage Pedigrees. For a general review, see genetic linkage in Kimball s Biology ... While male mutation carriers can develop breast cancer (particularly with BRCA2 mutations), females are at much greater risk. ... Genetic architecture: The overall characteristics of genetic risk such as the number of risk alleles, their allele frequency ...
more infohttp://www.dorak.info/epi/glosge.html

GENETIC EPIDEMIOLOGY GLOSSARY [M.Tevfik DORAK]GENETIC EPIDEMIOLOGY GLOSSARY [M.Tevfik DORAK]

... at the tip of the short arms has very high recombination frequency (the sex-averaged recombination frequency is 28% which, for ... See exercises on Gametes under Linkage and Linkage Pedigrees. For a general review, see genetic linkage in Kimball s Biology ... While male mutation carriers can develop breast cancer (particularly with BRCA2 mutations), females are at much greater risk. ... Genetic architecture: The overall characteristics of genetic risk such as the number of risk alleles, their allele frequency ...
more infohttp://dorakmt.tripod.com/epi/glosge.html

Genetic Determinants of the Network of Primary Metabolism and Their Relationships to Plant Performance in a Maize Recombinant...Genetic Determinants of the Network of Primary Metabolism and Their Relationships to Plant Performance in a Maize Recombinant...

Considering each bin as a marker, a genetic linkage map on the basis of recombination frequency was constructed; the map was ... Great efforts have been devoted to increasing agricultural production with decreased inputs to meet the needs of the rising ... To construct the genetic linkage map, we developed an economic go-wrong method integrating the Carthagene software (de Givry et ... After quality control, the SNPs with missing rate of ,10% and heterozygosity of ,10% were used to construct the genetic linkage ...
more infohttp://www.plantcell.org/content/27/7/1839.full

New Article Reveals the Low Down on Crossing over Definition Biology and Why You Must Take Action Today | SBPONew Article Reveals the Low Down on Crossing over Definition Biology and Why You Must Take Action Today | SBPO

Recombination frequencies can fluctuate between sexes. Genetic linkage describes the propensity of genes to be inherited ... Finding great running shoes is extremely important. ... Genetic linkage of this type can be naturally ended. Genetic ... Genetic linkage describes the propensity of genes to be inherited together as a consequence of their location on exactly the ... Recombination and Linkage Each human somatic cell consists of two of each kind of chromosome. ...
more infohttp://sbpo.org.br/new-article-reveals-the-low-down-on-crossing-over-definition-biology-and-why-you-must-take-action-today/

Robustness of linkage maps in natural populations: a simulation study | Proceedings of the Royal Society of London B:...Robustness of linkage maps in natural populations: a simulation study | Proceedings of the Royal Society of London B:...

The frequencies of recombination events are the focus of such a study, yet it is individual variation in recombination rate ... values ranged from frequency 0.67 in red deer to frequency 0.97 in great reed warblers). Where there was a discrepancy between ... 1997 A medium-density genetic linkage map of the bovine genome. Mamm. Genome. 8, 21-28. doi:10.1007/s003359900340. ... 2007 Linkage mapping of AFLP markers in a wild population of great reed warblers: importance of heterozygosity and number of ...
more infohttp://rspb.royalsocietypublishing.org/content/275/1635/695

CREUTZFELDT JAKOB DISEASE: September 2011CREUTZFELDT JAKOB DISEASE: September 2011

... thereby creating an equal-to-greater overall frequency of 12-bp insertions as compared to the frequency spectrum of 23-bp ... Moreover, high levels of linkage disequilibrium have been detected for genetic variation within the bovine PRNP promoter and ... First, the 23-bp and 12-bp regions are physically linked (~2-Kbp apart). Therefore, recombination is most likely rare given the ... We determined the frequencies of known genetic factors associated with differential susceptibility to BSE in B. indicus ...
more infohttp://creutzfeldt-jakob-disease.blogspot.com/2011_09_01_archive.html

Linkage disequilibrium patterns of the human genome across populations : Human Molecular GeneticsLinkage disequilibrium patterns of the human genome across populations : Human Molecular Genetics

The average recombination rates estimated by low-resolution genetic maps can only explain a small fraction of the variance ... We found, as expected, that Ashkenazi Jews display the greatest extent of homogeneity and African Americans the greatest extent ... We found that SNP allele frequencies are highly correlated between Ashkenazi Jews and Caucasians and somewhat distinct in ... In addition, Ashkenazi Jews have a modest increase in LD compared with Caucasians, and both have greater LD than African ...
more infohttp://oxfordindex.oup.com/view/10.1093/hmg/ddg088

HLA A1-B8-DR3-DQ2 - WikipediaHLA A1-B8-DR3-DQ2 - Wikipedia

Thus, A1::DQ2 haplotype is both long and shows greater deficiency of recombination (called linkage disequilibrium). ... DQ2 in frequency. Genetics of recombination in humans suggests that common haplotypes of this length that Cw7-B8 component ... is increased in patients and the genetic susceptibility to SLE cannot be distinguished.[33] Linkage could not be extended to ... And while the level of A-B linkage in general was nowhere near Cw-B linkage, the linkage between A1-Cw7-B8 was reasonably ...
more infohttps://en.wikipedia.org/wiki/HLA_A1-B8-DR3-DQ2

Genetic linkage - Linkage mapGenetic linkage - Linkage map

The greater the frequency of recombination (segregation) between two genetic markers, the farther apart they are assumed to be ... Recombination frequency is a measure of genetic linkage and is used in the creation of a genetic linkage map. A centimorgan (cM ... Genetic linkage - Linkage map Linkage map. A linkage map is a chromosome map of a species or experimental population that shows ... Recombination frequency. Recombination frequency (θ) is when crossing-over will take place between two loci (or genes) during ...
more infohttp://tech1207.blogspot.com/2008/01/genetic-linkage-linkage-map.html

Curt Jacob Stern
(1902-1981)Curt Jacob Stern (1902-1981)

Stern and Bridges reasoned that the greater the frequency of genetic recombination between known genetic markers, the further ... They used that information to develop a linkage map showing which characteristics are most often inherited together, and they ... Stern and Bridges observed the phenotypic results of genetic recombination in multiple generations of Drosophila offspring. ... increasing genetic diversity across generations. Stern relied on the processes of meiosis and recombination in his Columbia ...
more infohttps://embryo.asu.edu/pages/curt-jacob-stern-1902-1981

Frontiers | Genome-Wide Association Study for Identifying Loci that Affect Fillet Yield, Carcass, and Body Weight Traits in...Frontiers | Genome-Wide Association Study for Identifying Loci that Affect Fillet Yield, Carcass, and Body Weight Traits in...

A new linkage map was developed to create windows of 20 adjacent SNPs for use in the GWAS. The two windows with largest effect ... The two windows with largest effect for FY and FW were located on chromosome Omy9 and explained only 1.0 to 1.5% of genetic ... A new linkage map was developed to create windows of 20 adjacent SNPs for use in the GWAS. ... One window on Omy5 explained 1.4% and 1.0% of the genetic variance for BW10 and BW13, respectively. Three windows located on ...
more infohttps://www.frontiersin.org/articles/10.3389/fgene.2016.00203/full

November | 2019 | EGFR Tyrosine Kinase Inhibitors Activate AutophagyNovember | 2019 | EGFR Tyrosine Kinase Inhibitors Activate Autophagy

Background Linkage disequilibrium (LD) is the non-random association between allele frequencies at two loci. Recombination rate ... and transgenic mouse lines with different genetic backgrounds To research whether the distinctions in mutations, genetic ... pairs as a measure of linkage disequilibrium and focus on the proportion of SNP pairs with r2 greater than 0.8. Results ... and properties other than increased linkage disequilibrium may make these populations interesting in genetic epidemiology. ...
more infohttp://www.buyresearchchemicalss.net/2019/11/

Is complete genetic linkage possible? - Biology Stack ExchangeIs complete genetic linkage possible? - Biology Stack Exchange

... if recombination is possible, then it is possible for them to become unlinked at some frequency, even if that frequency is ... Why does allele linkage cause disproportionate phenotypic ratios?. 15. Genetic linkage greater than 50 centimorgans ... When co-inheritance is non-random the genes are in linkage disequilibrium. The genetic linkage between genes is measured in ... Complete genetic linkage does occur in some cases. Most of the Y chromosome (present as a single copy in males of many species ...
more infohttps://biology.stackexchange.com/questions/43460/is-complete-genetic-linkage-possible

What is a LOD Score? (with pictures)What is a LOD Score? (with pictures)

A LOD score is the likelihood of linkage between two genetic traits. If the LOD score is high, then the traits are closely ... This information is used to arrive at the recombination frequency, looking at how often genetic traits recombine. To be on the ... it means that there is a high probability of genetic linkage. Lower numbers indicate less likelihood of genetic linkage, ... If genes are on different chromosomes, for example, they are usually inherited separately, because a great deal of crossover ...
more infohttp://www.wisegeek.org/what-is-a-lod-score.htm
  • In complete-linkage Hierarchical Clustering, this process of combining data points into clusters of increasing size is repeated until all date as part of a single cluster. (wikipedia.org)
  • Again, under this type of analysis, a single resultant cluster signifies complete-linkage, since all data points are within the range of assigned similarity. (wikipedia.org)
  • A linkage is said to be complete when two or multiple characteristics are inherited and normally surface in two or further generations in their parental or original combinations, they are known as complete linkage. (byjus.com)
  • The F1 offspring AaBb produces gametes that are AB , Ab , aB , and ab with equal frequencies (25%) due to the law of independent assortment. (blogspot.com)
  • See also Grosse & Khoury, 2006 for the clinical utility of genetic testing, Offit, 2008 for issues surrounding genomic disease profiling, and Pharoah, 2008 for the possible utility of genomic profiling in breast cancer risk assessment. (dorak.info)
  • These data are best analyzed using Armitage trend test for genotype frequencies or by logistic regression in which the genotypes are represented as (-1), 0, (+1). (dorak.info)
  • He helped explain how genetic material transmits from parent to progeny, and how it functions in developing organisms. (asu.edu)
  • Linkages assist in maintaining a newly improved variety, crossing over, on the other hand, forms as a source of variations to produce new varieties. (byjus.com)
  • Selective sweeps happen when newly appeared (and hence still rare) mutations are advantageous and increase in frequency. (wikipedia.org)
  • The neutral allele that is linked to the adaptation will increase in frequency, in some cases until it becomes fixed in the population. (wikipedia.org)
  • This suggests that the mutational target zone here is large, that is, given particular selection pressures (cattle culture) mutants will arise in the background and increase in frequency which produce the phenotype of lactase persistence. (discovermagazine.com)
  • Differences between individuals within a species might be the consequence of genetic facets, of environmental elements, or a mixture of both. (sbpo.org.br)
  • The recent development of a high-density SNP array for rainbow trout has provided the needed tool for studying the underlying genetic architecture of this trait. (frontiersin.org)
  • Although most hybrids are disadvantaged as a consequence of genetic incompatibility, the fittest survive, irrespective of species boundaries. (sbpo.org.br)
  • Instead, the effective population size may depend on factors such as the recombination rate and the frequency and strength of beneficial mutations. (wikipedia.org)
  • The number of genes in LD within a region, and thus the physical extent of LD, will depend on effective population size and the local recombination rate. (genetics.org)
  • is being used to investigate the relationship between genetic and physical distances for regions of interest. (genetics.org)
  • Here we investigate the frequency of an allele (-13910*T) associated with lactase persistence in a Neolithic Scandinavian population. (discovermagazine.com)