A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.
A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)
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.
A type of mutation in which a number of NUCLEOTIDES deleted from or inserted into a protein coding sequence is not divisible by three, thereby causing an alteration in the READING FRAMES of the entire coding sequence downstream of the mutation. These mutations may be induced by certain types of MUTAGENS or may occur spontaneously.
Any detectable and heritable alteration in the lineage of germ cells. Mutations in these cells (i.e., "generative" cells ancestral to the gametes) are transmitted to progeny while those in somatic cells are not.
Protection from an infectious disease agent that is mediated by B- and T- LYMPHOCYTES following exposure to specific antigen, and characterized by IMMUNOLOGIC MEMORY. It can result from either previous infection with that agent or vaccination (IMMUNITY, ACTIVE), or transfer of antibody or lymphocytes from an immune donor (IMMUNIZATION, PASSIVE).
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.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The number of mutations that occur in a specific sequence, GENE, or GENOME over a specified period of time such as years, CELL DIVISIONS, or generations.
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.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
An individual having different alleles at one or more loci regarding a specific character.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
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.
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.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Biochemical identification of mutational changes in a nucleotide sequence.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
An individual in which both alleles at a given locus are identical.
An amino acid-specifying codon that has been converted to a stop codon (CODON, TERMINATOR) by mutation. Its occurance is abnormal causing premature termination of protein translation and results in production of truncated and non-functional proteins. A nonsense mutation is one that converts an amino acid-specific codon to a stop codon.
Any method used for determining the location of and relative distances between genes on a chromosome.
A subcomponent of complement C1, composed of six copies of three polypeptide chains (A, B, and C), each encoded by a separate gene (C1QA; C1QB; C1QC). This complex is arranged in nine subunits (six disulfide-linked dimers of A and B, and three disulfide-linked homodimers of C). C1q has binding sites for antibodies (the heavy chain of IMMUNOGLOBULIN G or IMMUNOGLOBULIN M). The interaction of C1q and immunoglobulin activates the two proenzymes COMPLEMENT C1R and COMPLEMENT C1S, thus initiating the cascade of COMPLEMENT ACTIVATION via the CLASSICAL COMPLEMENT PATHWAY.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Genes that influence the PHENOTYPE only in the homozygous state.
Established cell cultures that have the potential to propagate indefinitely.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
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.
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.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Deletion of sequences of nucleic acids from the genetic material of an individual.
Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.
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.
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.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
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.
Genotypic differences observed among individuals in a population.
A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).
Mutation process that restores the wild-type PHENOTYPE in an organism possessing a mutationally altered GENOTYPE. The second "suppressor" mutation may be on a different gene, on the same gene but located at a distance from the site of the primary mutation, or in extrachromosomal genes (EXTRACHROMOSOMAL INHERITANCE).
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
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.
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.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
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.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
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.
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).
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
A characteristic symptom complex.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
Transport proteins that carry specific substances in the blood or across cell membranes.
Proteins found in any species of bacterium.
The relationships of groups of organisms as reflected by their genetic makeup.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A phenomenon that is observed when a small subgroup of a larger POPULATION establishes itself as a separate and isolated entity. The subgroup's GENE POOL carries only a fraction of the genetic diversity of the parental population resulting in an increased frequency of certain diseases in the subgroup, especially those diseases known to be autosomal recessive.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
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.
Proteins produced from GENES that have acquired MUTATIONS.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
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.
The magnitude of INBREEDING in humans.
The rate dynamics in chemical or physical systems.
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).
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.
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.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Elements of limited time intervals, contributing to particular results or situations.
Proteins prepared by recombinant DNA technology.
A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
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.
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.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
The functional hereditary units of BACTERIA.
Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.
DNA present in neoplastic tissue.
Identification of genetic carriers for a given trait.
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.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
A raf kinase subclass found at high levels in neuronal tissue. The B-raf Kinases are MAP kinase kinase kinases that have specificity for MAP KINASE KINASE 1 and MAP KINASE KINASE 2.
That part of the genome that corresponds to the complete complement of EXONS of an organism or cell.
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.
A tumor suppressor gene (GENES, TUMOR SUPPRESSOR) located on human CHROMOSOME 17 at locus 17q21. Mutations of this gene are associated with the formation of HEREDITARY BREAST AND OVARIAN CANCER SYNDROME. It encodes a large nuclear protein that is a component of DNA repair pathways.
Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
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.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
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.
A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
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.
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
The ability of viruses to resist or to become tolerant to chemotherapeutic agents or antiviral agents. This resistance is acquired through gene mutation.
Proteins found in any species of fungus.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
A mutation named with the blend of insertion and deletion. It refers to a length difference between two ALLELES where it is unknowable if the difference was originally caused by a SEQUENCE INSERTION or by a SEQUENCE DELETION. If the number of nucleotides in the insertion/deletion is not divisible by three, and it occurs in a protein coding region, it is also a FRAMESHIFT MUTATION.
Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.
Mice bearing mutant genes which are phenotypically expressed in the animals.
Actual loss of portion of a chromosome.
Genes that have a suppressor allele or suppressor mutation (SUPPRESSION, GENETIC) which cancels the effect of a previous mutation, enabling the wild-type phenotype to be maintained or partially restored. For example, amber suppressors cancel the effect of an AMBER NONSENSE MUTATION.
An ethnic group with historical ties to the land of ISRAEL and the religion of JUDAISM.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.
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.
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)
Proteins obtained from ESCHERICHIA COLI.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
A nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.
Computer-based representation of physical systems and phenomena such as chemical processes.
Genetic diseases that are linked to gene mutations on the X CHROMOSOME in humans (X CHROMOSOME, HUMAN) or the X CHROMOSOME in other species. Included here are animal models of human X-linked diseases.
Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.
Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
The functional hereditary units of FUNGI.
Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
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.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.
Cytoplasmic vesicles formed when COATED VESICLES shed their CLATHRIN coat. Endosomes internalize macromolecules bound by receptors on the cell surface.
A tumor suppressor gene (GENES, TUMOR SUPPRESSOR) located on human chromosome 13 at locus 13q12.3. Mutations in this gene predispose humans to breast and ovarian cancer. It encodes a large, nuclear protein that is an essential component of DNA repair pathways, suppressing the formation of gross chromosomal rearrangements. (from Genes Dev 2000;14(11):1400-6)
A class of proteins involved in the transport of molecules via TRANSPORT VESICLES. They perform functions such as binding to the cell membrane, capturing cargo molecules and promoting the assembly of CLATHRIN. The majority of adaptor proteins exist as multi-subunit complexes, however monomeric varieties have also been found.
Nucleotide sequences located at the ends of EXONS and recognized in pre-messenger RNA by SPLICEOSOMES. They are joined during the RNA SPLICING reaction, forming the junctions between exons.
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)
A cell line derived from cultured tumor cells.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
The loss of one allele at a specific locus, caused by a deletion mutation; or loss of a chromosome from a chromosome pair, resulting in abnormal HEMIZYGOSITY. It is detected when heterozygous markers for a locus appear monomorphic because one of the ALLELES was deleted.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
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.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
A large, nuclear protein, encoded by the BRCA2 gene (GENE, BRCA2). Mutations in this gene predispose humans to breast and ovarian cancer. The BRCA2 protein is an essential component of DNA repair pathways, suppressing the formation of gross chromosomal rearrangements. (from Genes Dev. 2000;14(11):1400-6)
The analysis of a sequence such as a region of a chromosome, a haplotype, a gene, or an allele for its involvement in controlling the phenotype of a specific trait, metabolic pathway, or disease.
Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.
Small, monomeric GTP-binding proteins encoded by ras genes (GENES, RAS). The protooncogene-derived protein, PROTO-ONCOGENE PROTEIN P21(RAS), plays a role in normal cellular growth, differentiation and development. The oncogene-derived protein (ONCOGENE PROTEIN P21(RAS)) can play a role in aberrant cellular regulation during neoplastic cell transformation (CELL TRANSFORMATION, NEOPLASTIC). This enzyme was formerly listed as EC 3.6.1.47.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
The capability of an organism to survive and reproduce. The phenotypic expression of the genotype in a particular environment determines how genetically fit an organism will be.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
Congenital absence of or defects in structures of the eye; may also be hereditary.
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.
Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.
The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).
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.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.
The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.
Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.
An antineoplastic agent with alkylating properties. It also acts as a mutagen by damaging DNA and is used experimentally for that effect.
A social group consisting of parents or parent substitutes and children.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.
The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.
A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.
Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.
A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Glycoproteins found on the membrane or surface of cells.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
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.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
An essential amino acid that is physiologically active in the L-form.
Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).
Any codon that signals the termination of genetic translation (TRANSLATION, GENETIC). PEPTIDE TERMINATION FACTORS bind to the stop codon and trigger the hydrolysis of the aminoacyl bond connecting the completed polypeptide to the tRNA. Terminator codons do not specify amino acids.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymes
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.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
However, females with this mutation produce eggs that undergo normal development when fertilized. Adaptive maternal effects ... Additionally, epigenetics can refer to histone modifications or non-coding RNAs that create a sort of cellular memory. Cellular ... This is a maternal, not an adaptive maternal effect. In order to be an adaptive maternal effect, the mother's environment would ... For example, if a mutation is maternal effect recessive, then a female homozygous for the mutation may appear phenotypically ...
Adaptive divergence associated with chromosomal rearrangements led to rapid radiation of the four genera within the Hylobatidae ... based on certain assumptions about the generation time and mutation rate. The extinct Bunopithecus sericus was a gibbon or ... divergences among these genera have been hard to resolve due to radiative speciations and extensive incomplete lineage sorting ...
Genetic mutation will not only produce new forms of life, but it will also result in malignancy. One cannot have the one ... "A universe with the sort of beauty, diversity, sentience and sophistication of creatures that the biosphere now contains" could ... could have gotten adaptive complexity without going the route of natural selection... The Christian positively welcomes ... The mutation theory of evolution was proposed by a Dutch botanist, Hugo de Vries, one of the first geneticits. He asserted that ...
One proposed definition of constraint is "A property of a trait that, although possibly adaptive in the environment in which it ... Despite mutations, certain character variants are never produced. Thee variants are therefore developmentally impossible to ... of some sort. To make the concept more useful, it is therefore necessary to divide it into smaller units. First, one can ...
Evolution is considered by some to be path-dependent: mutations occurring in the past have had long-term effects on current ... If the economy follows adaptive expectations, future inflation is partly determined by past experience with inflation, since ... Placing the full-height quotation mark on the outside protected the smaller cast metal sort from damage if the word needed to ... life forms, some of which may no longer be adaptive to current conditions. For instance, there is a controversy about whether ...
Suh, A; Smeds, L; Ellegren, H (2015). "The Dynamics of Incomplete Lineage Sorting across the Ancient Adaptive Radiation of ... At some point, a mutation occurred and the ancestral population became polymorphic, with some individuals having G0 and others ... In human evolution, incomplete lineage sorting is used to diagram hominin lineages that may have failed to sort out at the same ... Incomplete lineage sorting of the human family tree is an area of great interest. There are a number of unknowns when ...
Genetic mutation will not only produce new forms of life, but it will also result in malignancy. One cannot have the one ... My case holds, however, against that sort of anti-God as well as the malicious one. The variety of anti-Gods alerts us to the ... could have gotten adaptive complexity without going the route of natural selection... The Christian positively welcomes ... The sort of virtues and values that freedom makes possible - such as trust, love, charity, sympathy, tolerance, loyalty, ...
Moreover, mutations in FTO can lead to developmental failures, brain atrophy and physiological disorders in adulthood. mRNA ... Some studies have shown that the modifications of tRNA can be dynamic and adaptive to the changes of the environment. Examples ... with up to one-fourth of the nucleosides in these molecules containing some sort of modification in eukaryotes. There are ... Editing and modifications to lncRNA have demonstrated to result in changes in RNA expression and rate of mutation. 5- ...
... of mutation and degradative change compared to the rest of the genome suggests an evolutionary explanation for the adaptive ... Due to this inability to sort through its gene content, the Y chromosome is particularly prone to the accumulation of "junk" ... High mutation rateEdit. The human Y chromosome is particularly exposed to high mutation rates due to the environment in which ... These two conditions combined put the Y chromosome at a greater opportunity of mutation than the rest of the genome.[12] The ...
The reason is that the program was written in BASIC, a sort of computer baby-talk. When I rewrote it in Pascal, it took 11 ... The number of copies per generation, and the chance of mutation per letter are not specified in Dawkins's book; 100 copies and ... as in adaptive landscapes. Dawkins then goes on to show that a process of cumulative selection can take far fewer steps to ... The terms of the program and the existence of the target phrase do however mean that such 'negative mutations' will quickly be ...
... or the adaptive loci are tightly linked to deleterious ones. Examples of adaptive traits that have been transferred via ... Sorting of incompatibilities between parent species, where one subset of these isolates the hybrid taxon against one parent and ... It has been shown to increase mutation rates, to activate transposable elements, and to induce chromosomal rearrangements. ... Genes and genomic regions that are adaptive may be readily introgressed between species e.g. in hybrid zones if they are not ...
... of mutation and degradative change compared to the rest of the genome suggests an evolutionary explanation for the adaptive ... Due to this inability to sort through its gene content, the Y chromosome is particularly prone to the accumulation of "junk" ... The increased mutation opportunity for the Y chromosome is reported by Graves as a factor 4.8. However, her original reference ... Thus, although a male may have a well adapted Y chromosome free of excessive mutation, it may never make it into the next gene ...
Despite the arguments "in favor of an adaptive immune response in sIBM, a purely autoimmune hypothesis for sIBM is untenable ... It may have different root causes unrelated to either polymyositis or sIBM.[citation needed] Mutations in valosin-containing ... suggested that a chain of events causes IBM-some sort of virus, likely a retrovirus, triggers the cloning of T cells. These T ...
Evolutionary algorithms use the Darwinian metaphor of random mutation, selection and the survival of the fittest to solve ... and adaptive intelligence. Evolutionary algorithms, a subfield of machine learning (itself a subfield of artificial ... natural/artificial design that allows scientists to compare complex designed artifacts against the background of the sorts of ... "selection and mutation." Humans, he insisted, are "not the products of chance and error," and "the universe is not the product ...
The LAVA transposon increases mutation rate and thus is supposed to have contributed to the rapid and greater change in Gibbons ... Adaptive divergence associated with chromosomal rearrangements led to rapid radiation of the four genera 5-7 Mya. Each genus ... due to radiative speciations and extensive incomplete lineage sorting. An analysis based on morphology suggests that the four ... which is a type of translocation mutation. The unusually high number of structural changes in the DNA and chromosomal ...
Inherited mutations caused by soot. Failure to replicate results; implausible mutation rate[75][76]. ... Steele, E. J. (1981). Somatic selection and adaptive evolution : on the inheritance of acquired characters (2nd ed.). ... that he had done nothing of the sort, since he had never mentioned blood in his writings. He pointed out that he regarded ... Because these mutations were supposedly passed on to subsequent generations, Harrison claimed that he had documented a case of ...
... when competing with small-effect mutations, they tend to win. But small-effect mutations still matter - a lot. They provide ... 2012). The Adaptive Landscape in Evolutionary Biology. Oxford University Press. Norrström, N.; Getz, W. M.; Holmgren, N. M. A ... Freeling, M. (2009). Bias in plant gene content following different sorts of duplication: tandem, whole-genome, segmental, or ... The mutation theory of evolution held that species went through periods of rapid mutation, possibly as a result of ...
The adaptive function of the nuclear membrane may have been to serve as a barrier to protect the genome from reactive oxygen ... Mutations in the inner nuclear membrane proteins can cause several nuclear envelopathies. The nuclear envelope is punctured by ... The rupture is rapidly repaired by a process dependent on "endosomal sorting complexes required for transport" (ESCRT) made up ...
... all sorts of unusual mutations could become fixed simply because the number of individuals was so small and each mutation has a ... For adaptive learning to be inherited, one would anticipate that changes in the genome, whether genetic or epigenetic, would be ... mutations that hold the key arise by chance and without foresight for the potential advantage or disadvantage of the mutation. ... In other words, a species need not originate in a series of gradual steps, each resulting from a mutation with a small effect, ...
"The Dynamics of Incomplete Lineage Sorting across the Ancient Adaptive Radiation of Neoavian Birds". PLoS Biology. 13 (8): ... With one time unit defined as the time taken to accumulate one mutation per site, any two lineages coalesce at the rate 2 θ {\ ... The divergence times ( τ {\displaystyle \tau } 's) are measured by the expected number of mutations per site from the ancestral ... The concept of incomplete lineage sorting ultimately reflects on persistence of polymorphisms across one or more speciation ...
In the adaptive immune system, the three preeminent sets of genes are those that code for the Mhc, T-cell receptor (Tcr), and B ... There were all sorts of problems associated with such an effort, most of which could, however, be alleviated by transferring a ... Hence H2 polymorphism was expected to have arisen by an unusually high mutation (evolutionary) rate in the house mouse after ... He was the first to include in an immunology textbook sections emphasizing the importance of the so-called non-adaptive immune ...
The confines between the self and the world are annulled to the point that the material body itself is no guarantee of the sort ... Variations that are the result of mutations in the biological sense and variations that are the result of individually acquired ... It comprises both computational and holistic, relational approaches towards understanding complex adaptive systems and, ... "more of an organic unity and cannot be understood as just an external composition of the sort of distinct substances that were ...
Mutations in these proteins can lead to heightened salt sensitivity and can limit plant growth. The effects of salinity has ... This acts as a sort of stock room when a species is plagued by the perils of natural selection. A variety of galling insects ... Voesenek, LA; Bailey-Serres, J (April 2015). "Flood adaptive traits and processes: an overview". The New Phytologist. 206 (1): ... One interesting thing that has been found in plants that are consistently exposed to drought, is their ability to form a sort ...
These can arise via incomplete splicing, V(D)J recombination in the adaptive immune system, mutations in DNA, transcription ... It was recently shown that bacteria also have a sort of 5' cap consisting of a triphosphate on the 5' end. Removal of two of ... Polyadenylation site mutations also occur. The primary RNA transcript of a gene is cleaved at the poly-A addition site, and 100 ...
When an individual gene in such a set is disrupted by mutation or targeted knockout, there can be little effect on phenotype as ... The backup hypothesis proposes that redundant genes remain in the genome as a sort of "back-up plan". If the original gene ... Three models have arisen to attempt to explain preservation of redundant genes: adaptive radiation, divergence, and escape from ... Gene redundancy, therefore, would allow both copies of the gene to accumulate mutations as long as the other was still able to ...
Accordingly, the level of selection (or, more generally, of sorting) has become the conceptual basis of a third definition, ... In their differential impact on species, mass extinctions introduce a strong non-adaptive aspect to evolution. A classic ... who suggested saltational evolutionary changes either due to mutations that affect the rates of developmental processes or due ... Genome evolution, like horizontal gene transfer, genome fusions in endosymbioses, and adaptive changes in genome size. Mass ...
... whereas adaptive laboratory evolution selects many genome-wide mutations that contribute to the fitness of actively growing ... whereas screening systems individually assay each variant and allow a quantitative threshold to be set for sorting a variant or ... Beneficial mutations are rare, so large numbers of random mutants have to be screened to find improved variants. 'Focused ... Therefore, an advantage of DE is that there is no need to understand the mechanism of the desired activity or how mutations ...
Many adaptive changes in Drosophila[60] and dogs[61] for example, are associated with TE insertions. ... Another sort of conflict that genomes face is that between the mother and father competing for control of gene expression in ... Any mitochondrial mutation that can affect the amount of resources the plant invests in the female reproductive functions at ... Stan Sawyer and Daniel L. Hartl[126] fitted models of this sort to a variety of bacterial TEs, and obtained quite good fits ...
It is argued that a random genetic mutation in humans has caused syntactic structures to appear in the mind. Therefore, the ... "It would seem to me that [cognitive linguistics] is the sort of linguistics that uses findings from cognitive psychology and ... ISBN 978-1-118-34613-6. Ellis, Nick C. (2011). "The emergence of language as a Complex Adaptive System". In Simpson, James (ed ... What is commonly perceived as grammar is an inventory of constructions; a complex adaptive system; or a population of ...
Most mutations within genes are neutral, having no effect on the organism's phenotype (silent mutations). Some mutations do not ... The Mendelian principle of independent assortment asserts that each of a parent's two genes for each trait will sort ... It is a common means of spreading antibiotic resistance, virulence, and adaptive metabolic functions. Although horizontal gene ... Small mutations can be caused by DNA replication and the aftermath of DNA damage and include point mutations in which a single ...
Evolutionary Origin and Adaptive Function of Meiosis, Meiosis. InTech. ISBN 978-953-51-1197-9.. ... This machinery is related to the eukaryotic ESCRT-III machinery which, while best known for its role in cell sorting, also has ... Because this function is so central to life, organisms with mutations of their 16s rRNA are unlikely to survive, leading to ... developed a new sequencing method that involved splitting the RNA into fragments that could be sorted and compared to other ...
There are several genetic mutations implicated in the disease, including loss of function PINK1 [89] and Parkin.[90] Loss of ... autophagy has been seen as an adaptive response to stress, which promotes survival, whereas in other cases it appears to ... mechanically damaged cytoskeleton components and directs these components through a ubiquitin-dependent autophagic sorting ... 1998). "Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism". Nature. 392 (6676): 605-8. doi:10.1038/ ...
There are several genetic mutations implicated in the disease, including loss of function PINK1[98] and Parkin.[99] Loss of ... autophagy has been seen as an adaptive response to stress, which promotes survival, whereas in other cases it appears to ... mechanically damaged cytoskeleton components and directs these components through a ubiquitin-dependent autophagic sorting ... Mutations of synuclien alleles lead to lysosome pH increase and hydrolase inhibition. As a result, lysosomes degradative ...
In recent years, experiments have been conducted drawing conclusions to brain size in association to the gene mutation that ... However, such differences should not be interpreted as imparting any sort of functional advantage or disadvantage; gross ... or in many cases are an adaptive feature for life in a colder environment. For instance, among modern Homo sapiens, northern ...
Mitochondrial DNA's mutation rate in mammals varies from region to region - some parts hardly ever change and some change ... Most paleontologists, however, still think that animals with the dentary-squamosal jaw joint and the sort of molars ... Derivation of mammals from a synapsid precursor, and the adaptive radiation of mammal species ...
These can arise via incomplete splicing, V(D)J recombination in the adaptive immune system, mutations in DNA, transcription ... It was recently shown that bacteria also have a sort of 5' cap consisting of a triphosphate on the 5' end.[24] Removal of two ... Polyadenylation site mutations also occur. The primary RNA transcript of a gene is cleaved at the poly-A addition site, and 100 ...
Crosses of this sort create what are sold as Black Sex-links, Red Sex-links, and various other crosses that are known by trade ... to be maintained in a random-mating population at a selection-mutation balance that would depend on the rate of mutation, the ... which are used in antigen presentation as part of the adaptive immune system. Each different copy of the genes is able to bind ... Within poultry, sex-linked genes have been used to create hybrids in which males and females can be sorted at one day old by ...
"Snakes Used to Have Legs and Arms … Until These Mutations Happened". Live Science. Archived from the original on 2016-10-22. ... Many modern snake groups originated during the Paleocene, alongside the adaptive radiation of mammals following the extinction ... The fork in the tongue gives snakes a sort of directional sense of smell and taste simultaneously.[39] They keep their tongues ... Python embryos even have fully developed hind limb buds, but their later development is stopped by the DNA mutations in the ZRS ...
Solé, R.V.; Fernández, P. & Kauffman, S.A. (2003). "Adaptive walks in a gene network model of morphogenesis: insights into the ... However, rates of diversification could remain at background levels and still generate this sort of effect in the surviving ... by assuming that DNA mutations accumulate at a constant rate. These "molecular clocks", however, are fallible, and provide only ... Mass extinctions are often followed by adaptive radiations as existing clades expand to occupy the ecospace emptied by the ...
It is not an albino, as the black pigments are scarcely affected.[72] The mutation changes a single amino acid in the ... Tigers grew in size, possibly in response to adaptive radiations of prey species like deer and bovids, which may have occurred ... "Sorting out tigers (Panthera tigris): mitochondrial sequences, nuclear inserts, systematics, and conservation genetics" (PDF) ... "Accumulation of Deleterious Mutations Due to Inbreeding in Tiger Population" (PDF). Archived from the original (PDF) on 10 May ...
... will turn out to be a sort of mixture & not true fusion, of two distinct individuals, or rather of innumerable individuals, as ...
Hvis en mutation forekommer i et gen, kan den nye allel påvirker træk genet kontrollere og ændre fænotypet af organismen.[48] ... Ved at bruge udtrykket tilpasning om den evolutionære proces og adaptive træk for produktet (den kropslige del eller funktion ... I kunstig selektion er den nye race eller sort som skabes, den ene med de tilfældige mutationer, som mennesker finder ... Eshel, Ilan (december 1973). "Clone-Selection and Optimal Rates of Mutation". Journal of Applied Probability. Sheffield, ...
April 2007). "Auditory and verbal working memory deficits in a child with congenital aniridia due to a PAX6 mutation". Int J ... Where a child has both auditory and language problems, it can be hard to sort out cause-and-effect.[11] ... an adaptive software available at home and in clinics worldwide, but overall, evidence for effectiveness of these computerised ... "Abnormal phonologic processing in familial lateral temporal lobe epilepsy due to a new LGI1 mutation". Epilepsia. 46 (1): 118- ...
In 2001, a DNA study of more than 12,000 men from 163 East Asian regions showed that all of them carry a mutation that ... not just the occurrence of shoveling of any sort".[2] Multiregionalists argue that marked (+++) shovel-shaped incisors only ... "Evidence that the adaptive allele of the brain size gene microcephalin introgressed into Homo sapiens from an archaic Homo ...
... who seem to believe in some sort of nonmaterial principle in organisms.[17] ...
Kin selection provides the framework for an adaptive strategy by which altruistic behavior is bestowed on closely related ... possibly as an adaptation to reduce the accumulation of mutations,[11] which then mature or degrade over the life course. At ... level of variability in menopausal symptoms across populations brings into question the plausibility of menopause as a sort of ... Pavard, Samuel; Metcalf, C. Jessica E.; Heyer, Evelyne (5 March 2008). "Senescence of reproduction may explain adaptive ...
Marie Curie spoke out against this sort of treatment, warning that the effects of radiation on the human body were not well ... Instead, surviving cells appear to have acquired a genomic instability which causes an increased rate of mutations in future ... This has been termed an 'adaptive response' and is related to hypothetical mechanisms of hormesis.[31] ... "Artificial Mutation of the Gene" (PDF). Science. LXVI (1699): 84-87. doi:10.1126/science.66.1699.84. PMID 17802387. Retrieved ...
This sort of mutation has been linked to different mutations, such as congenital adrenal hyperplasia. (See Stop codon.) ... mutations may accumulate and result in adaptive changes. ... Spontaneous mutationEdit. Spontaneous mutations occur with non- ... A heterozygous mutation is a mutation of only one allele.. *A homozygous mutation is an identical mutation of both the paternal ... A germline mutation gives rise to a constitutional mutation in the offspring, that is, a mutation that is present in every cell ...
Though biological evolution of some sort had become the primary mode of discussing speciation within science by the late-19th ... Creationists also argue that genetic mutations are strong evidence against evolutionary theory because, they assert, the ... the adaptive radiation of many different hominoid forms was well underway.[145] Evidence from the molecular dating of genetic ... claimed debates are not the sort of arena to promote science to creationists.[183] Scott says that "Evolution is not on trial ...
Achievement, adaptive behavior, attention, cognition, executive functioning, language, memory, motor skills, multisensory ... There is evidence supporting the theory that the father can cause FAS through long term epigenetic mutation of the father's ... Dependent living: Group home, living with family or friends, or some sort of assisted living, experienced by 80% of the ... Adaptive behavior: Poor impulse control, poor personal boundaries, poor anger management, stubbornness, intrusive behavior, too ...
Whereas Linnaeus aimed simply to create readily identifiable taxa, the idea of the Linnaean taxonomy as translating into a sort ... Mutation. *Natural selection. *Adaptation. *Polymorphism. *Genetic drift. *Gene flow. *Speciation. *Adaptive radiation ... the sorting of species into groups of relatives ("taxa") and their arrangement in a hierarchy of higher categories. This ...
Longevity gains from dietary restriction, or from mutations studied previously, yield smaller benefits to Drosophila than to ... "special sort of disease". Robert M. Perlman, coined the terms "aging syndrome" and "disease complex" in 1954 to describe aging. ... or correct genetic mutations, has been proposed as a future strategy to prevent aging.[92][93] ... "Extreme-longevity mutations orchestrate silencing of multiple signaling pathways". Biochim Biophys Acta. 1790 (10): 1075-83. ...
Evolutionary Origin and Adaptive Function of Meiosis, Meiosis. InTech. ISBN 978-953-51-1197-9.. ... This machinery is related to the eukaryotic ESCRT-III machinery which, while best known for its role in cell sorting, also has ... Because this function is so central to life, organisms with mutations of their 16s rRNA are unlikely to survive, leading to ... Woese argued that this group of prokaryotes is a fundamentally different sort of life. To emphasize this difference, Woese ...
When the relative abundance or biomass of each species is sorted into its respective trophic level, they naturally sort into a ... Levin, S. A. (1998). "Ecosystems and the biosphere as complex adaptive systems". Ecosystems. 1 (5): 431-436. CiteSeerX 10.1. ... and also acts as a catalyst for genetic mutation.[109][110][169] Plants, algae, and some bacteria absorb light and assimilate ... Behaviours can evolve by means of natural selection as adaptive traits conferring functional utilities that increases ...
New ideas have a striking similarity to genetic mutations. Now, let us look for a moment at genetic mutations. Mutations are, ... For Popper, theories are accepted or rejected via a sort of selection process. Theories that say more about the way things ... Yet, as it appears that the engine of biological evolution has, over many generations, produced adaptive traits equipped to ... Mutations in the genes that determine the structure of the control may then cause drastic changes in behaviour, preferences and ...
Blind fish do not roll back the mutations that led to eyes. Dollo's Law explains that evolution cannot be precisely and exactly ... DNA studies are also complicated by incomplete lineage sorting like with the Gibbon. ... Lake Malawi and Lake Tanganyika exemplifies adaptive radiation and species flock. The Cichlid's Tale recounts how, by ...
It must be adaptive evolution of a sort, a mutation: her kind must possess a pheromone that functions as a sexual attractant. ... But I also knew that I had brought a small measure of life, albeit of a temporary sort, to someone who had none of her own to ... Were gonna get all this sorted out, but I need you to be strong for me. Can you do that?". He nodded weakly. "I dont know ... After that, it was sort of tough to get work.. I did a lot of scurrying around at first, frantic to find identity and security ...
Department of Agriculture are trying to determine if an unexpected mutation in a popular GM grass, Tifton 85, is responsible ... Its as if producing cyanide has some sort of adaptive advantage to the grass. Why would Gaia do this? Its those evil ... They are testing to see if its a mutation because the weather events were not the ones they would have expected to produce ... Its as if producing cyanide has some sort of adaptive advantage to the grass. ...
Mutation is random with respect to adaptive advantage, although it is non-random in all sorts of other respects. It is ... Mutation is not systematically biased in the direction of adaptive improvement, and no mechanism is known (to put it mildly) ... Are Hox genes universal? Sort of. Are they the only genes at work in organisms? Not at all, and the other ones show a great ... Hey, he didnt even know about DNA and the causes of random mutations when he proposed them. And i think after 100+ years there ...
Some of these are adaptive. ID doesnt deny this, it merely says that the adaptive changes tend to have a "purposive" sort of ... The probability of a mutation for which there exists such an adaptive outcome is quite small with respect to the entire space ... It needs to be established that the mutation, or series of mutations, that led to the flagellum was of high enough probability ... "It needs to be established that the mutation, or series of mutations, that led to the flagellum was of high enough probability ...
Any sort of random mutation to these genes would be disastrous to the fishs vision.. Unfortunately, much of this type of ... 1 A new study confirms creationist predictions for a type of internal adaptive engineering in the genome.2. Many traits in ... and was believed to provide the ability to create rapid adaptive optic traits allowing the fish population to adjust to the ... associated with specific locations on the fishs chromosomes associated with the adaptive traits of the cichlid visual system. ...
The adaptive Lac+ mutations arise by two mutational processes: a recombination-dependent process that is highly active on the ... Most of the Lac+ mutations are due to the first process, which also produces nonselected mutations on the F′ episome. However, ... Although minor contributors to any one type of mutation, the hypermutators account for nearly all cases of multiple mutations. ... adaptive mutation. This phenomenon has been extensively studied in FC40, a strain ofEscherichia coli that cannot metabolize ...
MUTATION is ultimately essential for adaptive evolution in all populations. Mutations that affect the phenotype, however, are ... This sort of adaptive race between mutator and wild-type subpopulations was originally modeled analytically by Painter (1975b) ... their rate of adaptive evolution can be limited by the rate at which beneficial mutations arise. However, the adaptive ... mutation is usually harmful to individuals. The prevalence of deleterious mutations over beneficial mutations led A. H. ...
Then, a point mutation in the glpK gene promotes growth by improving glycerol utilization but results in increased carbon ... Here we show that a strain of Escherichia coli carrying mutations in the rpoC and glpK genes, derived from adaptation in ... However, the mechanisms of action are hard to decipher and little has been achieved for epistatic mutations, especially at the ... In a strain carrying both mutations, these contrasting carbon/energy saving and wasting mechanisms work together to give an 89 ...
"Natural selection directs evolution not by accepting or rejecting mutations as they occur, but by sorting new adaptive ... Having ruled out mutation as a "force", this left the idea of mutation as a source of "raw materials". That is, the architects ... Rates of evolution, including adaptive evolution as in Rokyta, et al, 2005, are sensitively dependent on rates of mutation, ... Even if mutation rates would increase by a factor of 10, newly introduced mutations would represent only a very small fraction ...
The extent to which a population diverges from its ancestor through adaptive evolution depends on variation supplied by novel ... the production of novel beneficial mutants from which selection sorts--is very general, being characterized by an approximately ... Distribution of fitness effects among beneficial mutations before selection in experimental populations of bacteria.. Kassen R1 ... Here we test these predictions by assaying the fitness of 665 independently derived single-step mutations in the bacterium ...
... those of virtually all species will contract to relatively low numbers and pass though metaphorical bottlenecks of the sort ... Compensatory Mutations, Antibiotic Resistance and the Population Genetics of Adaptive Evolution in Bacteria. Bruce R. Levin, ... Compensatory Mutations, Antibiotic Resistance and the Population Genetics of Adaptive Evolution in Bacteria. Bruce R. Levin, ... Compensatory Mutations, Antibiotic Resistance and the Population Genetics of Adaptive Evolution in Bacteria. Bruce R. Levin, ...
Furthermore, mutations fixed in the human influenza NP gene were associated with more CTL epitopes than were mutations fixed in ... this phenomenon has a major influence on evolutionary trajectories for organisms of all sorts. The role of epistasis has been ... Such subsequent mutations are said to represent a form of epistatic compensation. Second, a mutation with neutral or negative ... effects can sometimes permit an adaptive mutation that would not have been beneficial in the absence of the prior mutation. ...
... illustrating the sorts of unanticipated types of mutations found for broadly neutralizing antibodies against HIV. Lanzavecchia ... Epistasis in Adaptive versus Stochastic Evolution of the Influenza A Virus Nucleoprotein Gene. by Neil Greenspan , Jun 30, 2014 ... Epistasis refers to the influence of one genomic mutation or variant on the phenotypic effects of another mutation or variant. ... The role of epistasis has been studied primarily in the context of adaptive evolutionary change. In a recent paper (2014), Gong ...
Epistasis refers to the influence of one genomic mutation or variant on the phenotypic effects of another mutation or variant. ... Epistasis in Adaptive versus Stochastic Evolution of the Influenza A Virus Nucleoprotein Gene. by Neil Greenspan , Jun 30, 2014 ... this phenomenon has a major influence on evolutionary trajectories for organisms of all sorts. The role of epistasis has been ... Tissue-Specific Stem Cell Mutation, Selection, and Evolution as a Cause of Aging. by Neil Greenspan , Jan 31, 2016 , Article ...
In asexual reproduction, however, natural selection has to wait for some sort of mutation or change due to drift to take place ... This variation enables a species to overcome novel environmental changes by fast adaptive change. ... because the combination of beneficial mutations will occur more quickly and deleterious mutations will accumulate more slowly. ... Sexual reproduction can also put two beneficial mutations together (although there is always a possibility to break a favorable ...
If a gene is very long or if a single mutation or small subset of mutations are the only possible adaptive changes in that gene ... We used a combination of phylogenetic and statistical approaches to sort through these complex data, discern truly adaptive ... Adaptive genome of a P. aeruginosa population (replicate 1) evolving to colistin. Most adaptive genes had multiple mutations ... 1) (30). Those endpoint isolates that had acquired mutS mutations had 44 to 92 mutations each, while strains without mutations ...
Mutation is random with respect to adaptive advantage, although it is non-random in all sorts of other respects. It is ... Mutation is not systematically biased in the direction of adaptive improvement, and no mechanism is known (to put the point ... If it could be shown that some mutations, even a small proportion, are occurring by direction or are adaptive in some sense, ... "There is a fifth respect in which mutation might have been nonrandom. We can imagine (just) a form of mutation that was ...
Mutation is random with respect to adaptive advantage, although it is non-random in all sorts of other respects. It is ... Mutation is not systematically biased in the direction of adaptive improvement, and no mechanism is known (to put the point ... Mutations and Selection. Futuyma expresses that the variation that biological evolution needs comes from the random mutations ( ... mutations in the genes of these cells are copied to every cell of the offspring and expressed in its phenotype.¹ Mutations in ...
None except for mutations, and a curious and rather strange non-adaptive governor of sorts attached to our DNA. ... And what if we had a person that had no or few mutations. Each of us, quite literally, has 10s of millions of mutations in our ... But other mutations are far worse, and affect function. Some in subtle ways, others incompatible with life. Not one of us is ... So, yes, if you think this points to some sort of error on Matthews part, youd be a fool. Its called literary technique. ...
We have developed a scalable analysis pipeline to identify CRISPR/Cas9 induced mutations in hundreds of samples using next ... adaptive immunity. It has been adapted to enable high throughput genome editing and has revolutionised the generation of ... This enables us to combine screening with archiving to create a library of cryopreserved samples carrying known mutations. It ... The CRISPR/Cas9 system is a prokaryotic immune system that infers resistance to foreign genetic material and is a sort of ...
Theres been some sort of adaptive difference between humans and chimps.. In contrast, this one CIAS1, which affects an auto- ... The mutations in AGT affect hypertension, associated with coronary artery disease.. What happens if you have a high number of ... up constraint with adaptive evolution and just call it neutral.. So this is a little bit of a challenge and dN/dS is generally ... And as a result these mutations causing disease will stick around. within populations but never fix, and they eventually do get ...
... how particular behaviors are or may be adaptive, and why ... ... A random mutation arose in a male giving him this orange spot, ... Were sort of ignoring a little bit here issues of having two copies or ... Adaptive Behaviors and Sexual Selection. This module changes gears a bit to look at the exciting field of animal behavior-- ... So they have some sort of bias such that they prefer something about this ...
These new adaptive traits constantly arise as genetic mutations caused by means such as radioactivity, ultraviolet light, ... A great number have means of concealment from their enemies, of one sort or another. Many are enabled to escape extermination ... which tends to eliminate unfavorable mutations and generally perpetuates favorable mutations. Think of a prospector panning for ... Heritable adaptive traits are passed on to future generations and given enough time will spread to all members of a population ...
But sometimes those mutations lead to T cells or B cells that divide out of control, leading to leukemia or lymphoma. ... largely because its one of only a handful of organizations developing this sort of T and B cell genomic technology (San ... Adaptive Biotechnologies, a Fred Hutch spinoff, was founded on the idea that while the 6 billion letters of DNA that make up a ... Adaptive is hopeful that todays findings will help open that door to the diagnostic world. Flow cytometry, a technique that ...
But this sort of thing is more appropriate when comparing closely related species. In the paper on selective sweeps in humans ... Being very conservative one can infer that the fixation of lactose tolerance in Northern Europeans due to a mutation on the LCT ... Specifically, we develop a coalescent-based model for the shape of the entire curve and use it to infer adaptive parameters by ... Ergo, most evolutionary change was not adaptive. A simple way to check the power of selection against this background of ...
These new adaptive traits constantly arise as genetic mutations caused by means such as radioactivity, ultraviolet light, ... Great fecundity is generally of much avail.... A great number have means of concealment from their enemies, of one sort or ... which tends to eliminate unfavorable mutations and generally perpetuates favorable mutations. Think of a prospector panning for ... Heritable adaptive traits are passed on to future generations and given enough time will spread to all members of a population ...
First Rule of Adaptive Evolution. is stupid and wrong, isnt a real rule, and we have multiple examples that refute it, which ... Hynek had an excuse of sorts, at least not long before his death (his presentation was quite poor), while Behe appears to be ... Of course, they would disagree with his implication that that is the only process allowed or that no mutation could increase ... First Rule of Adaptive Evolution. falls flat on its face without explicitly saying its wrong by name, Behe thinks they didnt ...
A missense mutation that alters the protein binding affinity may cause significant perturbations or complete abolishment of the ... Mathematical and Numerical Aspects of the Adaptive Fast Multipole Poisson-Boltzmann Solver by Bo Zhang, Benzhuo Lu, Xiaolin ... Sorted by: Citation Count. Year (Descending). Year (Ascending). Recency. Results 1 - 10 of 15 Next 10 → ... A missense mutation that alters the protein binding affinity may cause significant perturbations or complete abolishment of the ...
... autism would be a disaster and that autism genes have stayed in the population because they provide some sort of adaptive or ... mutations and are not inherited. This contradicts the tenets of Temple Grandin who has claimed that eradicating ... Simon Baron-Cohen has made a similar claim that autism genes provide some sort of evolutionary adaption and this is the reason ... Kathleen Seidel supports this sort of bigotry as possibly does his wife, as a husband and wife will usually (though admittedly ...
... autism would be a disaster and that autism genes have stayed in the population because they provide some sort of adaptive or ... mutations and are not inherited. This contradicts the tenets of Temple Grandin who has claimed that eradicating ... Im sure they have some sort of alternative explanation though. Of course it doesnt rule out some sort of environmental insult ... changes in adaptive behavior, and quality of life variables. Further positive changes in mental health status as a result of ...
  • So basically if gene control determines up to an extent what genes will go through mutation, then a mechanism for directing evolution is provided. (biology-online.org)
  • 2 More specifically, the team analyzed gene expression (products of active genes) associated with specific locations on the fish's chromosomes associated with the adaptive traits of the cichlid visual system. (icr.org)
  • Any sort of random mutation to these genes would be disastrous to the fish's vision. (icr.org)
  • The prevalence of deleterious mutations over beneficial mutations led A. H. Sturtevant, in an early essay, to conclude that the mutation rate should evolve to the lowest value possible "given the nature of genes" ( S turtevant 1937 , p. 466). (genetics.org)
  • In this context, hitchhiking refers to the process whereby antibody-mediated selection for a particular hemagglutinin or neuraminidase gene sequences coincidentally leads to increased prevalence of particular NP gene sequences (including particular mutations) that happen to be found in the same viral genomes as the favored hemagglutinin or neuraminidase genes. (evmedreview.com)
  • Geneticists have recognized for some time that many genes exhibit pleiotropy, meaning that one mutation can manifest in two or more distinguishable phenotypic effects. (evmedreview.com)
  • Metagenomic deep sequencing revealed 2,657 mutations at ≥5% frequency in 1,197 genes and 761 mutations in 29 endpoint isolates. (asm.org)
  • This can be used to efficiently induce small insertions/deletions (indels), through inaccurate repair of double-strand breaks, preferably generating frameshift mutations to produce loss-of-function alleles for genes of interest. (biomedcentral.com)
  • The rule summarizes the fact that the overwhelming tendency of random mutation is to degrade genes, and that very often is helpful. (freethoughtblogs.com)
  • Contrary to Behe's laughable claim that Lents, Swamidass, and Lenski had no response to his central tenet, they did: they pointed out that he ignores the various ways evolution proceeds (it's not just by "breaking" genes), and that he runs away from the evidence of clear examples of mutations that increase complexity. (freethoughtblogs.com)
  • Some influence which genes are expressed and others modify the DNA using the so-called adaptive mutations . (blogspot.com)
  • Transcriptional activation of genes derepressed to various degrees would expose the nontranscribed strands to mutations and stimulate localized supercoiling. (blogspot.com)
  • People vary greatly when it comes to smell, largely due to chance mutations in the genes that code for the smell receptors rather than for adaptive reasons. (newscientist.com)
  • Let's assume there are about 10,000 genes in the snake where a loss-of-function mutation is lethal. (jonfwilkins.com)
  • Transposons seem to have been pivotal contributors to the evolution of adaptive immunity both in vertebrates and in microbes, which were only recently discovered to actually have a form of adaptive immunity-namely, the CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated genes) system that has triggered the development of a new generation of genome-manipulation tools. (the-scientist.com)
  • Mutation as a source of variation operates (in this model) almost independently of selection, adding new variation to the gene pool, while natural selection operates against the entire existing pool variation by altering the relative distribution of different alleles for genes with variation. (blogspot.com)
  • We then evolved the deletion strain and observed that the genetic adaptation was recurrently based on a strategic mutation that changed the anticodon of other tRNA genes to match that of the deleted one. (elifesciences.org)
  • Together, our observations shed light on the evolution of the tRNA pool, demonstrating that mutation in the anticodons of tRNA genes is a common adaptive mechanism when meeting new translational demands. (elifesciences.org)
  • At first this mutation resulted in slower growth of the yeast cells, but after being allowed to evolve over 200 generations, the rate of growth matched that of a normal strain with all transfer RNA genes. (elifesciences.org)
  • Common signatures of selection on visual and oxygen transport genes shared by distantly related deep-water species point to both adaptive introgression and independent selection. (nature.com)
  • Thus the proposed intrinsic HIVaINR antisense RNA microRNAs (HAAmiRNAs) of the human immunodeficiency virus form complementary targets with mRNAs of a key human gene in adaptive immunity, the IL-2Rγc, in which genetic defects are known to cause an X-linked severe combined immunodeficiency syndrome (X-SCID), as well as mRNAs of genes important in innate immunity. (biomedcentral.com)
  • His laboratory has discovered multiple specific forms of immunodeficiency including those caused by mutations in the genes encoding the intracellular signaling molecule Janus kinase 3. (nih.gov)
  • Sexual reproduction can also put two beneficial mutations together (although there is always a possibility to break a favorable combination too), or eliminate a deleterious one. (tripod.com)
  • Overall, groups reproducing sexually can evolve more quickly than those do not, because the combination of beneficial mutations will occur more quickly and deleterious mutations will accumulate more slowly. (tripod.com)
  • The other (which is really sort of another side of the same coin) is that sex permits more efficient purging of deleterious mutations. (jonfwilkins.com)
  • For instance, one of the things that we know is that the vast majority of naturally occurring mutations are deleterious. (blogspot.com)
  • Yet, somehow, evolution is able to maintain a level of function in the face of these deleterious mutations, and even to create new adaptations. (blogspot.com)
  • And sometimes an individual carrying a lot of deleterious mutations starts a polygamous cult and has about a hundred kids. (blogspot.com)
  • But on average, the filtering effects of selection seem to counterbalance, or even outweigh the effect of those deleterious mutations. (blogspot.com)
  • If the mutation is deleterious, it disappears quickly, and when looking at long time scales, we expect to see very few deleterious mutations that are old. (scienceblogs.com)
  • Therefore, the statistical models that predict the behavior of deleterious mutations over time are embedded in a good sense of reality, and as a result are pretty good too. (scienceblogs.com)
  • Given the estimates for the overall mutation rate in E. coli and its genomic deleterious mutation rate, our estimate of U a implies that 1 in 150 newly arising mutations is beneficial and that 1 in 10 fitness-affecting mutations increases the fitness of the individual carrying it. (evolverzone.com)
  • The main insight is that the pool of mutations on which this blind process of natural selection acts is larger and less biased toward deleterious changes than assumed. (evolverzone.com)
  • When rpsL mutants are maintained by serial passage (serial transfer) in streptomycin-free culture, the populations remain resistant to streptomycin but adapt to the fitness burden of the rpsL locus by compensatory mutations at other loci, which restore the efficacy of translation to nearly wild-type levels ( S chrag and P errot 1996 ). (genetics.org)
  • One of these things is that adaptive evolution operates by gene substitution at the specific loci coding for the phenotype(s) under selection. (genetics.org)
  • The typical path leading to a hypermutator phenotype is mutations in the DNA repair system, including the MutS/MutL class of proteins ( 14 , 16 , 17 ). (asm.org)
  • In bacteria, a wide range of mutations can be shown to provide a beneficial phenotype to the cell. (nickyfisher.com)
  • That is, two populations may be roughly equivalent in fitness and phenotype, but the presence of (probably) neutral mutations in one may enable other changes that predispose it to particular patterns of change. (scienceblogs.com)
  • For example, if a mutation is maternal effect recessive, then a female homozygous for the mutation may appear phenotypically normal, however her offspring will show the mutant phenotype, even if they are heterozygous for the mutation. (wikipedia.org)
  • These typically involve examining the phenotype of the organisms one generation later than in a conventional (zygotic) screen, as their mothers will be potentially homozygous for maternal effect mutations that arise. (wikipedia.org)
  • On another thread [ Visible Mutations and Evolution by Natural Selection ] we are discussing a common adaptationist claim that once a mutation has a visible phenotype it is almost certainly subject to selection. (blogspot.com)
  • This mutation has a phenotype in that the transition of m06-MHC-I complexes from early endosomes (EE) to late endosomes (LE)/lysosomes for degradation is blocked. (springer.com)
  • Nonadaptive mutations occur on the F' episome during adaptive mutation conditions in Escherichia coli. (semanticscholar.org)
  • To ascertain the conditions under which this compensatory evolution, rather than reversion, will occur, we did computer simulations, in vitro experiments, and DNA sequencing studies with low-fitness rpsL (streptomycin-resistant) mutants of E. coli with and without mutations that compensate for the fitness costs of these ribosomal protein mutations. (genetics.org)
  • Dobzhansky expressed similar views by stating "The most serious objection to the modern theory of evolution is that since mutations occur by 'chance' and are undirected, it is difficult to see how mutation and selection can add up to the formation of such beautifully balanced organs as, for example, the human eye. (blogspot.com)
  • This allows adaptive evolution to occur at a faster rate. (jonfwilkins.com)
  • Adaptive mutations of various sorts may help bacteria survive in adverse conditions and beneficial mutations do occur, as discussed thoroughly in "A Creationist Perspective of Beneficial Mutations in Bacteria," but they are not evidence for molecules-to-man evolution . (nickyfisher.com)
  • Strikingly, a systematic search in hundreds of genomes revealed that anticodon mutations occur throughout the tree of life. (elifesciences.org)
  • and thus, in each generation, new mutations occur in the presence of different alleles. (beds.ac.uk)
  • It is the normal Darwinian process of "random" mutation (with respect to fitness, but not such that all mutations are equally likely to occur) leading to increased or decreased reproductive output of individuals that happen to carry the mutation, with the proportion of genic variants changing over many generations. (evolverzone.com)
  • An experiment in which a flagellum evolves in immotile bacteria under selective pressure cannot reveal the full mechanism whereby the mutation occurs without establishing a complete deterministic chain of cause and effect accounting for every genetic, developmental and phenotypic aspect of the mutation. (uncommondescent.com)
  • We identified the mutations responsible for the high mutation rates and show that their rate of substitution in all three populations was too rapid to be accounted for simply by genetic drift. (genetics.org)
  • The results of recent in vitro experimental studies with a bacterium, Escherichia coli , and a retrovirus, human immunodeficiency virus (HIV), and an in vivo study with Salmonella typhimurium on the adaptation to the fitness burdens associated with drug resistance question these perceptions about the genetic basis of adaptive evolution for microorganisms. (genetics.org)
  • This is usually achieved through genetic mutation and selection, a slow process driven by chance. (phys.org)
  • One is that sex allows beneficial mutations that arise on different backgrounds to be recombined onto a single genetic background. (jonfwilkins.com)
  • All the mutations that developed involved the use or suppression of existing genetic information, not the generation of new genetic information. (nickyfisher.com)
  • It is describing how a new capability that requires some complex novelties can evolve, and it is saying plainly that in this case it is not by the fortuitous simultaneous appearance of a set of mutations, but is conditional on the genetic background of the population. (scienceblogs.com)
  • Because of the inheritance pattern of maternal effect mutations, special genetic screens are required to identify them. (wikipedia.org)
  • Why is there genetic variation in anciently adaptive traits? (blogspot.com)
  • For example, the transilience model of Templeton (class III), genetic revolution model of Mayr (class IV) or the frozen plasticity theory of Flegr (class V), suggests that adaptive evolution in sexual species is operative shortly after the emergence of a species by peripatric speciation - while it is evolutionary plastic. (beds.ac.uk)
  • So, when studying genetics of populations, geneticists have the ability to predict what the genetic variation should look like given the null conditions of a particular mutation rate, a particular population size and structure over time, and no positive selection. (scienceblogs.com)
  • of genetic variants (alleles) should look a certain way, and when they don't, you are probably looking at postitive (adaptive) selection. (scienceblogs.com)
  • The fitness effects of individual mutations were calculated as a function of drug environment, revealing the magnitude of epistatic interactions between mutations and genetic backgrounds. (biomedcentral.com)
  • Non-adaptive plasticity, too can interact with selection to promote or inhibit genetic differentiation. (hindawi.com)
  • Comparative whole-genome sequencing enables the identification of specific mutations during adaptation of bacteria to new environments and allelic replacement can establish their causality. (semanticscholar.org)
  • Distribution of fitness effects among beneficial mutations before selection in experimental populations of bacteria. (nih.gov)
  • An atheist, responding to one of my recent posts, insisted that bacteria has been observed to benefit from mutations. (nickyfisher.com)
  • Vials of bacteria, genetically engineered to have a metabolic problem, were used to see how bacterial mutations may help them overcome stress imposed on them. (nickyfisher.com)
  • Koonin hypothesized in 2005 that "spacer DNA" in the clustered regularly interspaced short palindromic repeats (CRISPR) loci of bacteria and archaea, which matched sequences of bacteriophages, could be a key part of a sort of adaptive immune system. (nih.gov)
  • 2007. Adaptive mutations in bacteria: high rate and small effects . (evolverzone.com)
  • In two of the populations, large gains in fitness relative to the ancestor occurred as the mutator alleles rose to fixation, strongly supporting the conclusion that mutator alleles fixed by hitchhiking with beneficial mutations at other loci. (genetics.org)
  • The capacity for asexual populations to evolve high mutation rates by hitchhiking has been demonstrated by experimental manipulations that enhance the probability of association between mutator alleles and beneficial mutations. (genetics.org)
  • In addition to known alleles such as pmrB, hypermutation allowed identification of additional adaptive alleles with epistatic relationships. (asm.org)
  • Mosaic sgRNA-injected individuals then need to be screened for those that transmit the appropriate alleles (e.g. frameshift indels or missense mutations). (biomedcentral.com)
  • Epistasis refers to the influence of one genomic mutation or variant on the phenotypic effects of another mutation or variant. (evmedreview.com)
  • We measured the genomic mutation rate that generates beneficial mutations and their effects on fitness in Escherichia coli under conditions in which the effect of competition between lineages carrying different beneficial mutations is minimized. (evolverzone.com)
  • nonsynonymous mutations will behave like synonymous mutations. (coursera.org)
  • Estimates from molecular data for the fraction of new nonsynonymous mutations that are adaptive vary strongly across plant species. (usda.gov)
  • Mitchell writes that some common examples of beneficial mutations are those involved in bacterial antibiotic resistance. (nickyfisher.com)
  • Such a high rate of adaptive evolution has implications for the evolution of antibiotic resistance and pathogenicity. (evolverzone.com)
  • Thus, in the absence of beneficial mutations, asexual populations are expected to evolve lower mutation rates than those of sexual populations ( K ondrashov 1995 ). (genetics.org)
  • below this threshold, the mutator clone will typically decline in frequency because the wild-type clone is more likely to be associated with new beneficial mutations. (genetics.org)
  • The extent to which a population diverges from its ancestor through adaptive evolution depends on variation supplied by novel beneficial mutations. (nih.gov)
  • Extending earlier work, recent theory makes two predictions that seem to be robust to biological details: the distribution of fitness effects among beneficial mutations before selection should be (i) exponential and (ii) invariant, meaning it is always exponential regardless of the fitness rank of the wild-type allele. (nih.gov)
  • We show that the distribution of fitness effects among beneficial mutations is indistinguishable from an exponential despite marked variation in the fitness rank of the wild type across environments. (nih.gov)
  • These results suggest that the initial step in adaptive evolution--the production of novel beneficial mutants from which selection sorts--is very general, being characterized by an approximately exponential distribution with many mutations of small effect and few of large effect. (nih.gov)
  • First, a mutation that potentially confers a net fitness advantage but is associated with negative phenotypic consequences can be made more beneficial by a subsequent mutation that somehow ameliorates the detrimental effects. (evmedreview.com)
  • Second, a mutation with neutral or negative fitness effects that persists for a period due to stochastic effects can sometimes permit an adaptive mutation that would not have been beneficial in the absence of the prior mutation. (evmedreview.com)
  • A non-adaptive or detrimental gene variant can also spread rapidly through a population if it is on the same DNA strand as a highly beneficial variant. (newscientist.com)
  • So, in this analogy, the first theory, the one about beneficial mutations, is like how you would take all of your albums and put the best songs together on a mix tape that you give to a girl you're trying to impress. (jonfwilkins.com)
  • Beneficial mutations. (evolverzone.com)
  • A reader asked me to post about beneficial mutations as an antidote to the common creationist (mis)conception that all mutations are detrimental. (evolverzone.com)
  • Here, we report an efficient computational approach for predicting the effect of single and multiple missense mutations on protein−protein binding affinity. (psu.edu)
  • This feature was found to be activated by hybridization (mating) and was believed to provide the ability to create rapid adaptive optic traits allowing the fish population to adjust to the conditions at hand. (icr.org)
  • Richardson considers three ways adaptive hypotheses can be evaluated, using examples from the biological literature to illustrate what sorts of evidence and methodology would be necessary to establish specific evolutionary and adaptive explanations of human psychological traits. (blogspot.com)
  • Mapping of quantitative trait loci controlling adaptive traits in coastal Douglas-fir. (usda.gov)
  • However, others suggested that phenotypically plastic traits can promote adaptive evolution and the origin of species [ 9 - 16 ]. (hindawi.com)
  • Each genus comprises a distinct, well-delineated lineage, but the sequence and timing of divergences among these genera have been hard to resolve due to radiative speciations and extensive incomplete lineage sorting. (wikipedia.org)
  • The test, if successful, would prove that differential reproduction and random mutation can produce flagella in non-motile bacterial populations, whether or not we had a record of each mutation and the probabilities associated with its fitness. (uncommondescent.com)
  • We studied the evolution of high mutation rates and the evolution of fitness in three experimental populations of Escherichia coli adapting to a glucose-limited environment. (genetics.org)
  • We show that simultaneous adaptive gains in both the mutator and wild-type subpopulations (clonal interference) retarded the mutator fixation in at least one of the populations. (genetics.org)
  • We found little evidence that the evolution of high mutation rates accelerated adaptation in these populations. (genetics.org)
  • MUTATION is ultimately essential for adaptive evolution in all populations. (genetics.org)
  • thus, despite its potential adaptive benefit to populations, mutation is usually harmful to individuals. (genetics.org)
  • The modifier models have generally upheld Sturtevant's conclusion that mutation rates should be minimized by natural selection, but they have identified important differences in the evolution of mutation rates between sexual and asexual populations. (genetics.org)
  • In asexual populations, indirect selection is stronger because associations between fitness mutations and mutation rate modifiers persist. (genetics.org)
  • That means fewer chances for evolution to throw up mutations that would reduce the size of the appendix or eliminate it altogether - and fewer chances for those mutations to spread through populations by natural selection. (newscientist.com)
  • It is important to be clear that this is not a matter of mutations occurring in response to need, nor of whole populations of individuals changing to become resistant simultaneously. (evolverzone.com)
  • 1 A new study confirms creationist predictions for a type of internal adaptive engineering in the genome. (icr.org)
  • Genome-wide hypermutation in a subpopulation of stationary-phase cells underlies recombination-dependent adaptive mutation. (semanticscholar.org)
  • It has been adapted to enable high throughput genome editing and has revolutionised the generation of targeted mutations. (biomedcentral.com)
  • Adaptive Biotechnologies, a Fred Hutch spinoff , was founded on the idea that while the 6 billion letters of DNA that make up a human genome are consistent in almost every cell of the body, the immune system's B cells and T cells are an exception. (xconomy.com)
  • This suggests a complete absence of lethal recessive mutations in the mother's genome. (jonfwilkins.com)
  • So, we would expect each maternal half-genome to contain, on average, about 3 lethal recessive mutations. (jonfwilkins.com)
  • By an increased rate of evolution, the authors mean an increased rate of adaptive change in the genome. (scienceblogs.com)
  • Because of this, molecular methods that identify resistance patterns via single SNPs in resistance-associated markers might be missing signals for resistance and compensatory mutation throughout the genome. (biomedcentral.com)
  • Another aspect of gene therapy is the way the genome is modified using different approaches, and how this modification could result in either a cure or a harmful mutation. (biomedcentral.com)
  • A 2014 whole-genome molecular dating analysis indicated that the gibbon lineage diverged from that of great apes (Hominidae) around 17 million years ago (16.8±0.9 Mya), based on certain assumptions about the generation time and mutation rate. (wikipedia.org)
  • The biochemist's 'neutral mutations' are more than neutral. (blogspot.com)
  • Increased episomal replication accounts for the high rate of adaptive mutation in recD mutants of Escherichia coli. (semanticscholar.org)
  • Global metabolic network reorganization by adaptive mutations allows fast growth of Escherichia coli on glycerol. (semanticscholar.org)
  • Recent in vivo and in vitro experimental studies of the adaptation to these "costs of resistance" in Escherichia coli , HIV, and Salmonella typhimurium found that evolution in the absence of these drugs commonly results in the ascent of mutations that ameliorate these costs, rather than higher-fitness, drug-sensitive revertants. (genetics.org)
  • We already know the RNA sequence of the virus very well, naturally, and that's allowing us both to track mutations and to lay out exactly what proteins it forces a cell to make once it gets ahold of the machinery. (sciencemag.org)
  • The endoplasmic reticulum (ER) coordinates the synthesis, folding, and sorting of proteins for retention in the cell or for entry into the secretory pathway. (diabetesjournals.org)
  • With these models, you can run simulations of the system, and see what happens when you perturb it a certain way, and therefore make predictions about what happens when you make mutations in the proteins of the system. (science20.com)
  • Based on available evidence and theory, this phenomenon has a major influence on evolutionary trajectories for organisms of all sorts. (evmedreview.com)
  • Analysis of the mutational trajectories revealed many more mutations in the human NP gene lineage (40 amino acid replacements over 44 years) than in the swine NP gene lineage (18 amino acid replacements over 55 years). (evmedreview.com)
  • thus, hypermutators explore the adaptive evolutionary trajectories leading to resistance more rapidly than with nonhypermutators. (asm.org)
  • The results of our investigation support the hypothesis that in these experiments, the ascent of intermediate-fitness compensatory mutants, rather than high-fitness revertants, can be attributed to higher rates of compensatory mutations relative to that of reversion and to the numerical bottlenecks associated with serial passage. (genetics.org)
  • These streptomycin-resistant rpsL strains with compensatory mutations are more fit than uncompensated rpsL mutants but less fit than wild-type streptomycin-sensitive rpsL + cells. (genetics.org)
  • Evidence that gene amplification underlies adaptive mutability of the bacterial lac operon. (semanticscholar.org)
  • This bacterial and archaeal adaptive immune system might be a therapeutic answer to previous incurable diseases, of course rigorous testing is required to corroborate these claims. (biomedcentral.com)
  • They deny your immune system the opportunity to practice its own adaptive response to invading microorganisms or viruses , thereby causing your immune system to atrophy in the same way that a wheelchair-bound person will experience leg muscle atrophy. (prisonplanet.com)
  • If that by itself can clear an infection, it certainly will - otherwise it sort of holds the line until the adaptive immune system can range in the artillery and commence firing. (sciencemag.org)
  • Adaptive divergence associated with chromosomal rearrangements led to rapid radiation of the four genera within the Hylobatidae lineage between about 7 to 5 Mya. (wikipedia.org)
  • Interestingly, the dramatic increase in mutation rate also means that many nonadaptive mutations accumulate and are carried along as "hitchhikers" that in the long run are likely to decrease the overall fitness of the organisms under nonselective conditions ( 18 , 19 ). (asm.org)
  • offer evidence for an example of pleiotropy in which the distinct phenotypic effects associated with mutation of the POLR3A gene, which encodes a subunit (RPC1) of RNA polymerase III, are associated with two different diseases: one or another form of cancer and an autoimmune disease (scleroderma). (evmedreview.com)
  • They may not be as similar as was once thought (by Ernst Haeckel in his famous argument that 'ontogeny [development] recapitulates phylogeny [evolution]'), but the essential mechanisms are conserved--fixed among diverse species (except perhaps for harmful mutations that always arise and are quickly removed by purifying natural selection). (blogspot.com)
  • They found that for the human NP homolog fixed mutations were found in more than the average number of CTL epitopes compared with average amino acid positions. (evmedreview.com)
  • In the swine NP homolog, fixed mutations were found in more than the average number of CTL epitopes compared with average amino acid positions. (evmedreview.com)
  • conservative when looking for adaptive amino-acid. (coursera.org)
  • In a recent paper (2014), Gong and Bloom attempt to determine the relative frequencies of epistatic interactions in adaptive versus stochastic evolution, i.e. evolution driven by selection as opposed to evolution resulting from random processes without a significant selective 'pressure. (evmedreview.com)
  • Ratcheting up adaptive fitness requires not just mutation but selective pressure. (ibiblio.org)
  • It has been proposed that maternal effects are important for the evolution of adaptive responses to environmental heterogeneity. (wikipedia.org)
  • In the absence of the selecting drugs, chromosomal mutations for resistance to antibiotics and other chemotheraputic agents commonly engender a cost in the fitness of microorganisms. (genetics.org)
  • We argue that these bottlenecks are intrinsic to the population dynamics of parasitic and commensal microbes and discuss the implications of these results to the problem of drug resistance and adaptive evolution in parasitic and commmensal microorganisms in general. (genetics.org)
  • The diversity and sophistication of immune systems are striking: their functions range from immediate and nonspecific innate responses to exquisitely choreographed adaptive responses that result in lifelong immune memory after an initial pathogen attack. (the-scientist.com)
  • Germain is an NIH Distinguished Investigator in the NIAID Lymphocyte Biology Section, where he studies basic aspects of innate and adaptive immune function, with an emphasis on the biochemical mechanisms involved in discrimination between self and foreign peptide-associated major histocompatibility complex (MHC) molecules by T cells as well as on T-cell antigen-presenting cell interactions and the subsequent delivery-of-effector function. (nih.gov)
  • This pivot mutation underlies the directional bias in evolution across the landscape, where evolution towards the ancestor is precluded across all examined drug concentrations from various starting points in the landscape. (biomedcentral.com)
  • Now, confronting a purer expression of those decentralist ideas than we then knew how to build, I worry that I may have encouraged a kind of utopianism - a belief that if we just cultivate enough decentralization and divergence of approach, good whole systems will just sort of coalesce out of the chaos without anyone having to make hard decisions. (ibiblio.org)
  • After making explicit my working definitions of key terms, I argue that the "developmental plasticity hypothesis of speciation" [ 13 - 15 ] is a special case of ecological speciation, and I review the subject by breaking down the effects of plasticity on the two components of ecological speciation: adaptive divergence and the evolution of reproductive isolation [ 28 ]. (hindawi.com)
  • This variation enables a species to overcome novel environmental changes by fast adaptive change. (tripod.com)
  • The usual casual, default, text or pop-sci view is that a trait with adaptive fitness value should come to be fixed in a species, as ribs and other things generally are. (blogspot.com)
  • Punctuational theories of evolution suggest that adaptive evolution proceeds mostly, or even entirely, in the distinct periods of existence of a particular species. (beds.ac.uk)
  • Adaptive evolution in sexual species according to frozen plasticity theory. (beds.ac.uk)
  • The hundreds of cichlid fish species in Lake Malawi constitute the most extensive recent vertebrate adaptive radiation. (nature.com)
  • These latter mutations are said to engage in permissive epistatic interactions. (evmedreview.com)
  • Through epistatic interactions with other mutations, this pivot creates an epistatic ratchet against reverse evolution towards the wild type ancestor, even in environments where the wild type is the most fit of all genotypes. (biomedcentral.com)
  • The presence of pivot mutations can dictate dynamics of evolution across adaptive landscape through epistatic interactions within a protein, leaving a population trapped on local fitness peaks in an adaptive landscape, unable to locate ancestral genotypes. (biomedcentral.com)
  • The compensatory mutations responsible for the adaptation to these fitness costs were through additional base substitutions at the protease locus. (genetics.org)
  • While hypermutation is a robust mechanism for rapid adaptation, it requires trade-offs between the adaptive mutations and the more common "hitchhiker" mutations that accumulate from the increased mutation rate. (asm.org)
  • In asexual reproduction, however, natural selection has to wait for some sort of mutation or change due to drift to take place, to act on. (tripod.com)
  • Mutation acquisition during selection is dependent on mutation supply, which can be boosted by hypermutation ( 14 , 15 ). (asm.org)
  • Behe is skeptical that gene duplication followed by random mutation and selection can contribute to evolutionary innovation. (freethoughtblogs.com)
  • The existence of such mechanisms has been predicted by mathematicians who argue that, if every mutation were really random and had to be tested against the environment for selection or rejection, there would not have been enough time to evolve the extremely complex biochemical networks and regulatory mechanisms found in organisms today. (blogspot.com)
  • Many scientists may share Dobzhansky's intuitive conviction that the marvelous intricacies of living organisms could not have arisen by the selection of truly random mutations. (blogspot.com)
  • So selection for one variant can have all sorts of seemingly unrelated effects. (newscientist.com)
  • Deep sequencing of the BCR from E2-specific class-switched memory B cells sorted from two independent participants revealed a focused repertoire suggestive of clonal selection. (jimmunol.org)
  • Assuming a mutation rate of 10 -9 , mutation-selection balance at each locus would have loss-of-function mutations circulating at a frequency of about 1 in 3000. (jonfwilkins.com)
  • This reduced progenitor pool fitness engenders selection for cells harboring oncogenic mutations, in part due to their ability to correct aging-associated functional defects. (jci.org)
  • A larger theoretical framework, embracing informational and structural roles for DNA, neutral as well as adaptive causes of complexity, and selection as a multilevel phenomenon, is needed. (pnas.org)
  • Darwin's theory of natural selection accounts for the "design" of organisms, and for their wondrous diversity, as the result of natural processes, the gradual accumulation of spontaneously arisen variations (mutations) sorted out by natural selection. (pnas.org)
  • Mutation and selection have jointly driven the marvelous process that, starting from microscopic organisms, has yielded orchids, birds, and humans. (pnas.org)
  • However, some biologists promote plasticity as a source of novelty and a factor in evolution on par with mutation, drift, gene flow, and selection. (hindawi.com)
  • Adaptive phenotypic plasticity can be a buffer against divergent selection. (hindawi.com)
  • Evolution by natural selection is driven by the continuous generation of adaptive mutations. (evolverzone.com)
  • Mutation is not systematically biased in the direction of adaptive improvement, and no mechanism is known (to put it mildly) that could guide mutation in directions that are non-random in this sense. (biology-online.org)
  • Mutation is random with respect to adaptive advantage, although it is non-random in all sorts of other respects. (biology-online.org)
  • Hey, he didn't even know about DNA and the causes of random mutations when he proposed them. (biology-online.org)
  • It wouldn't mean that gene control would determine the course of evolution, that's just silly, but it would mean that a lot of the randomness when discussing mutations isn't as random as the basic textbooks might let you understand. (biology-online.org)
  • No, jaredl - to prove that, you'd need to show that the key point mutations were actually "random" (acausal)…that their occurrence resolved to no deterministic mechanism or active probabilistic tendency resolving to a mechanism in some conceivable theory and model of the phenomenon. (uncommondescent.com)
  • Gráphagos demonstrates how graphic design can emerge when random mutations are selected and accumulated. (denizcemonduygu.com)
  • Going back to cartoons, starting around 1970 there were a series of debates which hinged around the role of deterministic adaptive forces and random neutral ones in the domain of evolutionary process. (discovermagazine.com)
  • Essentially, evolutionary change, and the amount of evolutionary change that happens in a population, begins with mutation (happening at a certain rate) and continues through either random processes that cause a mutation to become more or less common over short to medium time scales. (scienceblogs.com)
  • If the mutation is neutral (does not have an effect one way or the other) then we expect to see the mutation become more common over time, then less common, them more common, in a kind of random walk. (scienceblogs.com)
  • This in turn depends on the random process of mutation as well as on the previous history of the organisms. (pnas.org)
  • Random mutations and chance extinctions-events Gould called "historical contingencies"-would build on each other, he suggested, driving the evolution of life down one path or another. (nautil.us)
  • Mutations, however, do not produce new information such as would be required to evolve new, more complex kinds of organisms. (nickyfisher.com)
  • Some mutations enable an organism to adapt to its environment, but such mutations have never been shown to produce new kinds of organisms. (nickyfisher.com)
  • The adaptive features of organisms could now be explained, like the phenomena of the inanimate world, as the result of natural processes, without recourse to an Intelligent Designer. (pnas.org)
  • Here we test these predictions by assaying the fitness of 665 independently derived single-step mutations in the bacterium Pseudomonas fluorescens across a range of environments. (nih.gov)
  • http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T7C-4J14P1Y-4&_user=1111158&_coverDate=09%2F30%2F2006&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1309861100&_rerunOrigin=google&_acct=C000051676&_version=1&_urlVersion=0&_userid=1111158&md5=a9d8a4574f033a9b588512a584088cc5 (5)]]] ''L. plantarum'' is a gram positive bacterium that is found in a variety of niches. (kenyon.edu)
  • 1996 ) found that in tissue culture the mutations responsible for resistance to a protease inhibitor severely reduce the replication rate of this retrovirus. (genetics.org)
  • And they'll rise at some sort of constant rate. (coursera.org)
  • This potentiating change increased the mutation rate to Cit(+) but did not cause generalized hypermutability. (scienceblogs.com)
  • It was in this spirit that Maynard Smith (1976b) wrote: "I interpret 'rate of evolution' as a rate of adaptive change. (blogspot.com)
  • That is a download something torn and of kit in the eukaryotic mutations of your extraction estimated to the scholarly VP of the V. only of Combining your responsible download something torn of whatever or Chief whatever Officer, you should read no solutions until you are popular & and a example article conflict. (lightseed.com)
  • In Evolutionary Psychology as Maladapted Psychology, Robert Richardson takes a critical look at evolutionary psychology by subjecting its ambitious and controversial claims to the same sorts of methodological and evidential constraints that are broadly accepted within evolutionary biology. (blogspot.com)
  • 2013) illustrating the sorts of unanticipated types of mutations found for broadly neutralizing antibodies against HIV. (evmedreview.com)
  • This creates a "viral breeding ground" which encourages more rapid virus mutations that make vaccines obsolete anyway. (prisonplanet.com)
  • Tetramer-specific B cells exhibited skewed CDR3 length distribution and increased mutation frequency compared with naive B cells. (jimmunol.org)
  • A missense mutation that alters the protein binding affinity may cause significant perturbations or complete abolishment of the function, potentially leading to diseases. (psu.edu)
  • Members of its m02 - m16 gene family code for type-I transmembrane glycoproteins, proven or predicted, most of which carry cargo sorting motifs in their cytoplasmic, C-terminal tail. (springer.com)
  • However, in the course of passage in the absence of the protease inhibitor, the fitness burden of these resistance mutations declined and the level of resistance increased. (genetics.org)
  • Of course, they would disagree with his implication that that is the only process allowed or that no mutation could increase complexity or that novel functions can not increase the fitness of an individual. (freethoughtblogs.com)
  • These adaptive maternal effects lead to phenotypes of offspring that increase their fitness. (wikipedia.org)
  • Mismatch repair protein MutL becomes limiting during stationary-phase mutation. (semanticscholar.org)
  • 2013) showed that several human influenza NP mutations that became fixed during NP evolution despite destabilizing the structure of the protein occurred at sites associated with more than an average number of CTL epitopes and were therefore presumably escape variants. (evmedreview.com)
  • The availability of computational methods to evaluate the impact of mutations on protein−protein binding is critical for a wide range of biomedical applications. (psu.edu)
  • This process, known as ER stress, activates the adaptive unfolded protein response (UPR), a conserved set of molecular pathways that leads to decreased protein synthesis and misfolding and to increased protein degradation and autophagy, overall aiming to restore cellular homeostasis ( 1 , 2 ). (diabetesjournals.org)
  • ER stress can have internal cellular causes (e.g., increased protein synthesis, inefficient protein folding linked to mutations) or may be triggered by factors external to cells. (diabetesjournals.org)
  • This irreversibility suggests that the structure of an adaptive landscape for a resistance protein should be understood before considering resistance management strategies. (biomedcentral.com)
  • Recovery of phenotypes obtained by adaptive evolution through inverse metabolic engineering. (semanticscholar.org)
  • Cell surface receptor uptake via clathrin-mediated endocytosis (CME) and subsequent intracellular sorting for degradation or recycling regulates the strength and specificity of downstream signaling. (rupress.org)
  • I speculate that sustained up-regulation and/or acute activation of dynamin-1 in cancer cells contributes to a program of "adaptive" CME that alters signaling to enhance cancer cell survival, migration, and proliferation. (rupress.org)
  • While the cargo sorting motif is critically involved in the disposal of m06-bound MHC-I in the endosomal/lysosomal pathway at the stage of EE to LE transition, this motif-mediated disposal is not the critical step by which m06 causes immune evasion. (springer.com)
  • We rather propose that engagement of AP-1A/3A by the cargo sorting motif in m06 routes the m06-MHC-I complexes into the endosomal pathway and thereby detracts them from the constitutive cell surface transport. (springer.com)
  • up constraint with adaptive evolution and just call it neutral. (coursera.org)
  • Phenotypic plasticity was once seen primarily as a constraint on adaptive evolution or merely a nuisance by geneticists. (hindawi.com)
  • The role of epistasis has been studied primarily in the context of adaptive evolutionary change. (evmedreview.com)
  • A single mutation of large effect (S117N) serves as a pivot point for evolution to high resistance regions of the landscape. (biomedcentral.com)
  • This proposed mechanism for constraints on reverse evolution corroborates evidence from the field indicating that phenotypic reversal often occurs via compensatory mutation at sites independent of those associated with the forward evolution of resistance. (biomedcentral.com)