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.
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 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 sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
An individual having different alleles at one or more loci regarding a specific character.
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.
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.
Biochemical identification of mutational changes in a 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.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
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 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.
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.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
An individual in which both alleles at a given locus are identical.
Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Genes that influence the PHENOTYPE only in the homozygous state.
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.
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 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.
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.
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.
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 outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Any method used for determining the location of and relative distances between genes on a chromosome.
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).
Established cell cultures that have the potential to propagate indefinitely.
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 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 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 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.
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.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.
A characteristic symptom complex.
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.
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.
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).
Proteins produced from GENES that have acquired MUTATIONS.
The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
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.
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.
The magnitude of INBREEDING in humans.
Proteins found in any species of bacterium.
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.
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.
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.
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.
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.
Identification of genetic carriers for a given trait.
That part of the genome that corresponds to the complete complement of EXONS of an organism or cell.
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.
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
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.
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.
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.
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.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Transport proteins that carry specific substances in the blood or across cell membranes.
The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.
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.
DNA present in neoplastic tissue.
Genotypic differences observed among individuals in a population.
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.
The functional hereditary units of BACTERIA.
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).
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.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
A 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).
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.
The ability of viruses to resist or to become tolerant to chemotherapeutic agents or antiviral agents. This resistance is acquired through gene mutation.
Proteins prepared by recombinant DNA technology.
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.
An ethnic group with historical ties to the land of ISRAEL and the religion of JUDAISM.
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 age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.
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.
The rate dynamics in chemical or physical systems.
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).)
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.
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.
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.
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.
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.
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.
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.
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 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.
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.
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.
Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.
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 nitrosourea compound with alkylating, carcinogenic, and mutagenic properties.
The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.
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.
Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.
The functional hereditary units of FUNGI.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.
Mice bearing mutant genes which are phenotypically expressed in the animals.
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.
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.
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.
A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.
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)
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.
Proteins found in any species of fungus.
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.
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
Proteins obtained from ESCHERICHIA COLI.
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.
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.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
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.
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.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Congenital absence of or defects in structures of the eye; may also be hereditary.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
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.
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.
Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.
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)
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.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.
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).
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.
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
The analysis of a sequence such as a region of a chromosome, a haplotype, a gene, or an allele for its involvement in controlling the phenotype of a specific trait, metabolic pathway, or disease.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
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.
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 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.
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.
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.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
An antineoplastic agent with alkylating properties. It also acts as a mutagen by damaging DNA and is used experimentally for that effect.
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.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
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.
An essential amino acid that is physiologically active in the L-form.
Actual loss of portion of a chromosome.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.
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.
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).
Abnormal development of cartilage and bone.
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.
A social group consisting of parents or parent substitutes and children.
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.
A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.
Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.
Proteins that are normally involved in holding cellular growth in check. Deficiencies or abnormalities in these proteins may lead to unregulated cell growth and tumor development.
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.
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.
A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.
A cell line derived from cultured tumor cells.
Tumor suppressor genes located in the 5q21 region on the long arm of human chromosome 5. The mutation of these genes is associated with familial adenomatous polyposis (ADENOMATOUS POLYPOSIS COLI) and GARDNER SYNDROME, as well as some sporadic colorectal cancers.
The phosphoprotein encoded by the BRCA1 gene (GENE, BRCA1). In normal cells the BRCA1 protein is localized in the nucleus, whereas in the majority of breast cancer cell lines and in malignant pleural effusions from breast cancer patients, it is localized mainly in the cytoplasm. (Science 1995;270(5237):713,789-91)
A general term for the complete loss of the ability to hear from both ears.
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 spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
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 non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.
A reverse transcriptase encoded by the POL GENE of HIV. It is a heterodimer of 66 kDa and 51 kDa subunits that are derived from a common precursor protein. The heterodimer also includes an RNAse H activity (RIBONUCLEASE H, HUMAN IMMUNODEFICIENCY VIRUS) that plays an essential role the viral replication process.
Diseases that are caused by genetic mutations present during embryo or fetal development, although they may be observed later in life. The mutations may be inherited from a parent's genome or they may be acquired in utero.
Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.
Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.
A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
The relationships of groups of organisms as reflected by their genetic makeup.
Diseases caused by abnormal function of the MITOCHONDRIA. They may be caused by mutations, acquired or inherited, in mitochondrial DNA or in nuclear genes that code for mitochondrial components. They may also be the result of acquired mitochondria dysfunction due to adverse effects of drugs, infections, or other environmental causes.
In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.
Tumors or cancer of the COLON or the RECTUM or both. Risk factors for colorectal cancer include chronic ULCERATIVE COLITIS; FAMILIAL POLYPOSIS COLI; exposure to ASBESTOS; and irradiation of the CERVIX UTERI.
Hearing loss resulting from damage to the COCHLEA and the sensorineural elements which lie internally beyond the oval and round windows. These elements include the AUDITORY NERVE and its connections in the BRAINSTEM.
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Gyrase binds to DNA as a heterotetramer consisting of two A and two B subunits. In the presence of ATP, gyrase is able to convert the relaxed circular DNA duplex into a superhelix. In the absence of ATP, supercoiled DNA is relaxed by DNA gyrase.
Tumors or cancer of the human BREAST.
Genes which regulate or circumscribe the activity of other genes; specifically, genes which code for PROTEINS or RNAs which have GENE EXPRESSION REGULATION functions.
Elements of limited time intervals, contributing to particular results or situations.
Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.
The process by which two molecules of the same chemical composition form a condensation product or polymer.
A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.

Modified peptidoglycan transpeptidase activity in a carbenicillin-resistant mutant of Pseudomonas aeruginosa 18s. (1/138264)

A carbenicillin-resistant mutant of Pseudomonas aeruginosa 18s was found to possess peptidoglycan transpeptidase activity significantly more resistant to inhibition by benzyl penicillin, ampicillin, carbenicillin, and cephaloridine than that of the parent strain. The mutant was more resistant than the parent strain to all of the beta-lactam antibiotics tested, and 50% inhibition values for these compounds against membrane-bound model transpeptidase activity paralleled this increase. The resistance of the mutant to kanamycin, streptomycin, and chloramphenicol was unchanged.  (+info)

Marker effects on reversion of T4rII mutants. (2/138264)

The frequencies of 2-aminopurine- and 5-bromouracil-induced A:T leads to G:C transitions were compared at nonsense sites throughout the rII region of bacteriophage T4. These frequencies are influenced both by adjacent base pairs within the nonsense codons and by extracodonic factors. Following 2AP treatment, they are high in amber (UAG) and lower in opal (UGA) codons than in allelic ochre (UAA) codons. In general, 5BU-induced transitions are more frequent in both amber and opal codons than in the allelic ochre codons. 2AP- and 5BU-induced transition frequencies in the first and third positions of opal codons are correlated with those in the corresponding positions of the allelic ochre codons. Similarly, the frequencies of 2AP-induced transition in the first and second positions of amber codons and their ochre alleles are correlated. However, there is little correlation between the frequencies of 5BU-induced transitions in the first and second positions of allelic amber and ochre codons.  (+info)

Nonbehavioral selection for pawns, mutants of Paramecium aurelia with decreased excitability. (3/138264)

The reversal response in Paramecium aurelia is mediated by calcium which carries the inward current during excitation. Electrophysiological studies indicate that strontium and barium can also carry the inward current. Exposure to high concentrations of barium rapidly paralyzes and later kills wild-type paramecia. Following mutagenesis with nitrosoguanidine, seven mutants which continued to swim in the ;high-barium' solution were selected. All of the mutants show decreased reversal behavior, with phenotypes ranging from extremely non-reversing (;extreme' pawns) to nearly wild-type reversal behavior (;partial' pawns). The mutations fall into three complementation groups, identical to the pwA, pwB, and pwC genes of Kunget al. (1975). All of the pwA and pwB mutants withstand longer exposure to barium, the pwB mutants surviving longer than the pwA mutants. Among mutants of each gene, survival is correlated with loss of reversal behavior. Double mutants (A-B, A-C, B-C), identified in the exautogamous progeny of crosses between ;partial' mutants, exhibited a more extreme non-reversing phenotype than either of their single-mutant (;partial' pawn) parents.---Inability to reverse could be expected from an alteration in the calcium-activated reversal mechanism or in excitation. A normal calcium-activated structure was demonstrated in all pawns by chlorpromazine treatment. In a separate report (Schein, Bennett and Katz 1976) the results of electrophysiological investigations directly demonstrate decreased excitability in all of the mutants, a decrease due to an altered calcium activation. The studies of the genetics, the survival in barium and the electro-physiology of the pawns demonstrate that the pwA and pwB genes have different effects on calcium activation.  (+info)

Testing for selective neutrality of electrophoretically detectable protein polymorphisms. (4/138264)

The statistical assessment of gene-frequency data on protein polymorphisms in natural populations remains a contentious issue. Here we formulate a test of whether polymorphisms detected by electrophoresis are in accordance with the stepwise, or charge-state, model of mutation in finite populations in the absence of selection. First, estimates of the model parameters are derived by minimizing chi-square deviations of the observed frequencies of genotypes with alleles (0,1,2...) units apart from their theoretical expected values. Then the remaining deviation is tested under the null hypothesis of neutrality. The procedure was found to be conservative for false rejections in simulation data. We applied the test to Ayala and Tracey 's data on 27 allozymic loci in six populations of Drosophila willistoni . About one-quarter of polymorphic loci showed significant departure from the neutral theory predictions in virtually all populations. A further quarter showed significant departure in some populations. The remaining data showed an acceptable fit to the charge state model. A predominating mode of selection was selection against alleles associated with extreme electrophoretic mobilities. The advantageous properties and the difficulties of the procedure are discussed.  (+info)

Apontic binds the translational repressor Bruno and is implicated in regulation of oskar mRNA translation. (5/138264)

The product of the oskar gene directs posterior patterning in the Drosophila oocyte, where it must be deployed specifically at the posterior pole. Proper expression relies on the coordinated localization and translational control of the oskar mRNA. Translational repression prior to localization of the transcript is mediated, in part, by the Bruno protein, which binds to discrete sites in the 3' untranslated region of the oskar mRNA. To begin to understand how Bruno acts in translational repression, we performed a yeast two-hybrid screen to identify Bruno-interacting proteins. One interactor, described here, is the product of the apontic gene. Coimmunoprecipitation experiments lend biochemical support to the idea that Bruno and Apontic proteins physically interact in Drosophila. Genetic experiments using mutants defective in apontic and bruno reveal a functional interaction between these genes. Given this interaction, Apontic is likely to act together with Bruno in translational repression of oskar mRNA. Interestingly, Apontic, like Bruno, is an RNA-binding protein and specifically binds certain regions of the oskar mRNA 3' untranslated region.  (+info)

oko meduzy mutations affect neuronal patterning in the zebrafish retina and reveal cell-cell interactions of the retinal neuroepithelial sheet. (6/138264)

Mutations of the oko meduzy (ome) locus cause drastic neuronal patterning defect in the zebrafish retina. The precise, stratified appearance of the wild-type retina is absent in the mutants. Despite the lack of lamination, at least seven retinal cell types differentiate in oko meduzy. The ome phenotype is already expressed in the retinal neuroepithelium affecting morphology of the neuroepithelial cells. Our experiments indicate that previously unknown cell-cell interactions are involved in development of the retinal neuroepithelial sheet. In genetically mosaic animals, cell-cell interactions are sufficient to rescue the phenotype of oko meduzy retinal neuroepithelial cells. These cell-cell interactions may play a critical role in the patterning events that lead to differentiation of distinct neuronal laminae in the vertebrate retina.  (+info)

Cancer genetics: tumor suppressor meets oncogene. (7/138264)

The adenomatous polyposis coli (APC) tumor suppressor protein is inactivated by mutations in the majority of colorectal cancers. A recent study has revealed that alterations in the APC signaling pathway can result in the transcriptional activation of the c-MYC gene.  (+info)

Alzheimer's disease: clues from flies and worms. (8/138264)

Presenilin mutations give rise to familial Alzheimer's disease and result in elevated production of amyloid beta peptide. Recent evidence that presenilins act in developmental signalling pathways may be the key to understanding how senile plaques, neurofibrillary tangles and apoptosis are all biochemically linked.  (+info)

TY - JOUR. T1 - Analysis of pathway mutation profiles highlights collaboration between cancer-associated superpathways. AU - Gu, Yunyan. AU - Zhao, Wenyuan. AU - Xia, Jiguang. AU - Zhang, Yuannv. AU - Wu, Ruihong. AU - Wang, Chenguang. AU - Guo, Zheng. PY - 2011/9/1. Y1 - 2011/9/1. N2 - The biological interpretation of the complexity of cancer somatic mutation profiles is a major challenge in current cancer research. It has been suggested that mutations in multiple genes that participate in different pathways are collaborative in conferring growth advantage to tumor cells. Here, we propose a powerful pathway-based approach to study the functional collaboration of gene mutations in carcinogenesis. We successfully identify many pairs of significantly comutated pathways for a large-scale somatic mutation profile of lung adenocarcinoma. We find that the coordinated pathway pairs detected by comutations are also likely to be coaltered by other molecular changes, such as alterations in multifunctional ...
AIM: We assessed the diagnostic accuracy of epidermal growth factor receptor (EGFR) mutant-specific antibodies for detecting two common activating EGFR mutations. METHODS: Immunohistochemical expression of mutation-specific antibodies against EGFR exon 19 deletion E746-A750 ((c.2235_2249del15 or c.2236_2250del15, p. Glu746_Ala750del) and exon 21 L858R point mutation (c.2573T|G, p.Leu858Arg) were assessed in a cohort of 204 resected early stage node negative lung adenocarcinomas, and protein expression was compared with DNA analysis results from mass spectrometry analysis. RESULTS: Of seven cases with L858R point mutation, six were positive by immunohistochemistry (IHC). There were three false positive cases using L858R IHC (sensitivity 85.7%, specificity 98.5%, positive predictive value 66.7%, negative predictive value 99.5%). All seven E746-A750 exon 19 deletions identified by mutation analysis were positive by IHC. Four additional cases were positive for exon 19 IHC but negative by mutation analysis.
Mitochondrial diseases, which altogether represent not so rare diseases, can be due to mutations either in the nuclear or mitochondrial genomes. Several model organisms or cell lines are usually employed to understand the mechanisms underlying diseases, yeast being one of them. However, in the case of mutations within the mitochondrial genome, yeast is a major model because it is a facultative aerobe and its mitochondrial genome can be genetically engineered and reintroduced in vivo. In this short review, I will describe how these properties can be exploited to mimic mitochondrial pathogenic mutations, as well as their limits. In particular; pathological mutations of tRNA, cytb, and ATPase genes have been successfully modeled. It is essential to stress that what has been discovered with yeast (molecular mechanisms underlying the diseases, nuclear correcting genes, import of tRNA into mitochondria or compounds from drug screening) has been successfully transferred to human patient lines, paving the way
Since Fishers (1930) development of the geometric model of the process of adaptation, it has been assumed that a mutation that affects many parts of a complex organism is less likely to be beneficial than a mutation of more restricted effect. Direct evidence supporting the generality of this supposition has been difficult to obtain, in part because of the challenge of studying high-dimensional phenotypes (Houle 2010) and because of the lack of information on the relationship between effects of pleiotropic alleles on phenotypes vs. on fitness (Paaby and Rockman 2013). By using multivariate statistical modeling of the genetic variance generated by new mutations, and of the standing genetic variance in a natural population, we have shown that selection is consistently stronger on pleiotropic mutations, supporting Fishers model of adaptation for populations in the vicinity of an adaptive optimum (Zhang 2012).. In general, we inferred strong selection acting against new mutations affecting the ...
Thesis Defense. Title: Computational Detection of Driver Mutations in Cancer Genomes. Abstract: Cancer is caused largely by the accumulation of somatic mutations during the lifetime of an individual. Recent advances in next generation sequencing (NGS) enable measurement of somatic mutations in a cohort of samples. Large-scale cancer sequencing projects like The Cancer Genome Atlas (TCGA) have generated a huge amount of somatic mutations in thousands of tumors. This thesis addresses two challenges. The first challenge is to distinguish driver mutations that are responsible for cancer development from passenger mutations, random events that do not contribute to the cancer phenotype in a cohort of samples. This is a difficult problem because most somatic mutations measured in tumor samples are passenger mutations, and only a small portion of these mutations are driver mutations. The second challenge is to accurately identify larger genomic variants, also known as structural variants (SV), one type ...
Author Summary Cancer is the consequence of an evolutionary process, which lasts several decades, is impossible to observe during most of its time, and only becomes apparent in late stages. We use mathematical modeling to shed light on the evolutionary dynamics of cancer by studying the accumulation of passenger mutations. We show that the frequencies obtained by passenger mutations depend strongly on the ratio of death and birth rates of cancer cells. We use genetic data of colorectal cancer to estimate this important quantity in vivo. We estimate the size of the cancer cell population that was present when a specific mutation first emerged. Our theory informs the analysis of cancer sequencing data and the phylogenetic reconstruction of cancer evolution.
...A specific gene mutation may be useful in predicting the level of aggr...The mutation called BRAF V600E is a genetic alteration in the BRAF o...Past studies have shown that the mutation frequently occurs in the mos...The findings come at an important time as both the incidence of thyroi...,Presence,of,gene,mutation,helps,guide,thyroid,cancer,treatment,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters
To study the cost of chromosomal drug resistance mutations to bacteria, we investigated the fitness cost of mutations that confer resistance to different classes of antibiotics affecting bacterial protein synthesis (aminocyclitols, 2-deoxystreptamines, macrolides). We used a model system based on an in vitro competition assay with defined Mycobacterium smegmatis laboratory mutants; selected mutations were introduced by genetic techniques to address the possibility that compensatory mutations ameliorate the resistance cost. We found that the chromosomal drug resistance mutations studied often had only a small fitness cost; compensatory mutations were not involved in low-cost or no-cost resistance mutations. When drug resistance mutations found in clinical isolates were considered, selection of those mutations that have little or no fitness cost in the in vitro competition assay seems to occur. These results argue against expectations that link decreased levels of antibiotic consumption with the ...
Epidemiological evidence has long associated environmental mutagens with increased cancer risk. However, links between specific mutation-causing processes and the acquisition of individual driver mutations have remained obscure. Here we have used public cancer sequencing data to infer the independent effects of mutation and selection on driver mutation complement. First, we detect associations between a range of mutational processes, including those linked to smoking, ageing, APOBEC and DNA mismatch repair (MMR) and the presence of key driver mutations across cancer types. Second, we quantify differential selection between well-known alternative driver mutations, including differences in selection between distinct mutant residues in the same gene. These results show that while mutational processes play a large role in determining which driver mutations are present in a cancer, the role of selection frequently dominates ...
Summary: Continuous cultures of the tryptophan-requiring strain of Escherichia coli known as wp2 were continuously exposed to gamma radiation for periods of several generation times. The frequency of prototrophic revertants increased steadily during irradiation at a rate which was proportional to the radiation dose rate. The change of revertant frequency per unit dose (rad) was equal to the induced reversion rate per mutable unit. This mutation rate (ρ) was independent of population density but slightly dependent upon the presence of supplements, such as nutrient broth, to the normal minimal medium with tryptophan. There was a marked dependence of ρ upon culture temperature, the values at 16°, 22° and 37° being 1·2 × 10-11, 2·4 × 10-11 and 3·9 × 10-11 per mutable unit per rad. It is probable that only a fraction of radiation-induced changes in the genetic material which could give rise to phenotypic reversions are actually expressed, this fraction being dependent on the post-irradiation
The genetic factors underpinning the development of cancers are being discovered at an increasing pace. Cancers can have an acquired or an inherited genetic aetiology. Inherited cancer predisposition caused by a single gene mutation is normally inherited in an autosomal dominant fashion. Acquired caner at the cellular level may be caused by the loss of function of both copies of the gene acting in an autosomal recessive fashion. Gene mutations may act in different ways, some drive cell growth-oncogenes, others when the gene mutates fail to stop tumour growth - tumour suppressor genes. Other genetic mutations may cause normal DNA and cellular repair mechanisms to fail. Genetic testing may be used at the level of a tumour to inform treatment decisions or in an inherited cancer susceptibility syndrome to provide information and tailor screening and prevention strategies.
Eukaryotic cells contain numerous compartments, which have different protein constituents. Proteins are typically directed to compartments by short peptide sequences that act as targeting signals. Translocation to the proper compartment allows a protein to form the necessary interactions with its partners and take part in biological networks such as signalling and metabolic pathways. If a protein is not transported to the correct intracellular compartment either the reaction performed or information carried by the protein does not reach the proper site, causing either inactivation of central reactions or misregulation of signalling cascades, or the mislocalized active protein has harmful effects by acting in the wrong place. Numerous methods have been developed to predict protein subcellular localization with quite high accuracy. We applied bioinformatics methods to investigate the effects of known disease-related mutations on protein targeting and localization by analyzing over 22,000 missense
Complex processes such as transcription, replication, repair, and recombination require changes in chromatin structure and the interactions of numerous trans-acting factors with DNA sequences, raising the possibility that these processes may be interrelated. Here the effect of transcription on the rate of spontaneous mutation in the yeast Saccharomyces cerevisiae was examined. With the use of a lys2 frameshift allele under the control of a highly inducible promoter, the rate of spontaneous reversion was shown to increase when the mutant gene was highly transcribed. Thus, transcriptionally active DNA and enhanced spontaneous mutation rates are associated in yeast.. ...
e deficient for the mismatch repair (MMR) gene Msh2 show accelerated tumourigenesis and a reduced apoptotic response to DNA damage of methylation type. Here we examine the effect of mutation for Msh2 on in vivo mutation frequencies in the intestine as determined by loss of function at the Dolichos biflorus (Dlb-1) locus. Spontaneous mutation frequencies were scored in cohorts of ageing mice either wild type or mutant for Msh2. In mice less than 1 year old, mutation frequencies were only elevated in Msh2 null mice. However, beyond this age heterozygous Msh2 mice showed significantly higher mutation frequencies than controls. These findings implicate a gene dose dependent requirement for Msh2 in mutation suppression and prompted an analysis of young Msh2 mutants following exposure to DNA damage. Following exposure to N-methyl-N-nitro-N-nitrosoguanidine (MNNG), Msh2 deficient mice show a reduced apoptotic response and an increase in mutation frequency. Heterozygotes did not differ from controls. ...
Open-access immunosequencing data | Weber, Jeffrey | Cancer Immunology Research | Adaptive Biotechnologies | To understand prognostic factors for outcome between differentially sequenced nivolumab and ipilimumab in a randomized phase II trial, we measured T-cell infiltration and PD-L1 by immunohistochemistry, T-cell repertoire metrics, and mutational load within the tumor. We used next-generation sequencing (NGS) and assessed the association of those parameters with response and overall survival. Immunosequencing of the T-cell receptor -chain locus (TCR) from DNA of 91 pretreatment tumor samples and an additional 22 pairs of matched pre- and post treatment samples from patients who received nivolumab followed by ipilimumab (nivo/ipi), or the reverse (ipi/nivo), was performed to measure T cell clonality and fraction. Mutational and neoantigen load were also assessed by NGS in 82 of the 91 patients. Tumors were stained using immunohistochemistry for PD-L1+ and CD8+ T cells. Pretreatment tumor TCR
A gene mutation may accelerate the loss of memory and thinking skills in people who are at risk for Alzheimers disease, according to a study published in the May 3, 2017, online issue of Neurology®, the medical journal of the American Academy of Neurology.
THE number of compensatory mutations that will affect a specific deleterious mutation is a fundamental evolutionary quantity of which little is known. A mutation is compensatory if it has a beneficial effect on fitness that is conditional on the presence of a deleterious mutation at a different site in the genome (Kimura 1985). Hence, a compensatory effect is the outcome of a strong epistatic interaction between two mutations. Each compensatory mutation represents an alternate genetic solution to adaptation; thus, fitness recovery from the accumulation of deleterious mutations becomes less likely to occur by back mutation when compensatory mutations are increasingly common (Whitlock and Otto 1999). Indeed, one must invoke a compensatory mutation to explain the rapid, stepwise recovery of fitness observed in mutationally degraded experimental populations (Burch and Chao 1999; Moore et al. 2000; Estes and Lynch 2003). Compensatory mutations are also implicated in the persistence of alleles that ...
When populations of microorganisms are exposed to nonlethal selections, mutations that relieve the selective pressure arise (7), a phenomenon called adaptive mutation (6). Although it originally seemed that only useful mutations appeared (7), it is now clear that selected mutations are accompanied by nonselected mutations, i.e., the process is not directed to useful genes (12).. Most research on adaptive mutation has focused on a strain of Escherichia coli, called FC40, that cannot utilize lactose (Lac−) but that readily reverts to lactose utilization (Lac+) when lactose is its only carbon source (6). The process that produces adaptive Lac+ mutations is not the same as that which produces Lac+ mutations during normal growth. Unlike growth-dependent mutations, almost all adaptive Lac+ mutations are dependent on recombination functions (6, 10, 24). While several different types of sequence changes revert the Lac− allele during growth, adaptive Lac+ mutations are almost all −1-bp frameshifts ...
A fundamental task in precision oncology is to perform mutation profiling of tumors, which traditionally requires invasive tumor biopsy. Liquid biopsy, which requires a simple blood draw, provides a surrogate option for tumor biopsy. Liquid biopsy is noninvasive, repeatable, and especially useful when a tumors location makes tissue biopsy unfeasible.. However, the mutation profiling of cell-free DNA (cfDNA) is challenging, as conventional mutation callers are primarily designed for the mutation calling of genomic DNA. Unlike tumor biopsy, cfDNA is a mixture of DNA derived from tumors and that from normal cells, where tumor-derived cfDNA accounts for a minor fraction. As a result, mutations from tumors have weak signals in blood samples and are therefore hard to identify using conventional methods.. To address this challenge, in our recent work published in Nature Communications [1], we present cfSNV, a cfDNA somatic single nucleotide variant (SNV) caller with five innovative techniques to ...
Population included 59% of adenocarcinoma, 37% of women and 19% of non-smokers. Overall mutation rate is 46%: 31 EGFR mutations (13%) and 78 KRAS mutations (33%); 40 new mutations compared to previous study were found: 9 EGFR and 31 KRAS. In the ERMETIC 2 cohort, OS and PFS remained significantly (global test p < 0.01) better for EGFR mutated (hazard ration [HR] 0.57 [95%CI: 0.33-1.00] and 0.47 [0.28-0.78] respectively) and worse for KRAS mutated (HR 1.35 [0.97-1.88] and 1.16 respectively [0.85-1.59]) compared to wild-type (WT) NSCLC. No prognostic significant difference was found in the 177 pts common to both cohorts between pts with KRAS mutation in both cohorts (n= 28) and those with new (n = 31) mutations. In the 228 pts with several techniques, KRAS mutations detected by less sensitive technique (n = 42) have a lower OS compared to WT than those detected only by the best sensitive technique (n = 34), but are not significantly different: 1.63 (1.09-2.44) and 1.08 (0.69-1.69); results between ...
Hollander, W F., Hydrocephalic-polydactyl, a recessive pleiotropic mutant in the mouse and its location in chromosome 6. (1976). Subject Strain Bibliography 1976. 3055 ...
A mutation in a single gene can cause endometrial cancer that is responsive to a specific drug therapy, researchers at UT Southwestern Medical Center have found in an animal study.
3799 Genomic instability involves the accumulation of mutations and is a hallmark of neoplastic development in gastrointestinal malignancies such as colorectal carcinoma. Mutations in specific cancer genes contribute to the malignant phenotype for colorectal carcinoma. For example, mutations in APC, KRAS and TP53 are critical to the development of colorectal cancer. Mutations in genes like EGFR influence the response of molecular-targeted therapies. Undoubtedly, there are other critical gene mutations to be discovered and comprehensive mutation discovery from individual cancer genomes will increase our understanding of the genetics underlying any individual tumors phenotype. This mutation profile may provide prognostic and predictive genetic biomarkers. However, current technologies are severely limited in screening large numbers of genes for mutations. As a solution, we describe the development and application of a novel resequencing strategy for point mutation discovery on a massively ...
A mutation is any change occurring in the message that a gene carries. Mutations mainly arise as copy errors when DNA is replicated at mitosis and meiosis. Darwinian evolution requires a constant supply of variation: much of it is supplied by mutation, and a mutation-selection balance can maintain a genetic polymorphism. The first major geneticist to study mutation was H.J. Muller, who demonstrated it can be induced by X-rays. He also recognized that the rate of mutation in nature is extremely low, and that they are almost always deleterious to the fitness of the organism. The accumulation of deleterious mutations places a mutational load on the population. Mutations can occur at single base level or at chromosomal level. The effects of mutation can occasionally be very dramatic: some of these fruitflies have suffered mutations which alter the number of wings that develop... Is mutation directed?. ...
Rare mutations in the switch III region of Ras can increase its nanoscale clustering, which enhances effector recruitment and downstream signaling.
|p>p53 is a tumor suppressor protein encoded by the TP53 gene that responds to DNA damage by regulating cell-cycle arrest, apoptosis and senescence. These p53 Hotspot Mutation Cell Panels are composed of select cell lines derived from tumors of various tissue origins. The p53 mutational status of these lines have been sequenced and validated by ATCC.|/p>
|p>p53 is a tumor suppressor protein encoded by the TP53 gene that responds to DNA damage by regulating cell-cycle arrest, apoptosis and senescence. These p53 Hotspot Mutation Cell Panels are composed of select cell lines derived from tumors of various tissue origins. The p53 mutational status of these lines have been sequenced and validated by ATCC.|/p>
Researchers assigned levels of risk to 25 mutations associated with breast and ovarian cancer in a large, Stanford-led study. The results may be helpful in guiding treatment and screening recommendations.
Listing of all Polbase results with context for Reference: Amino acid changes coded by bacteriophage T4 DNA polymerase mutator mutants. Relating structure to function., Polymerase: T4 G298D, Property: Nucleotide Substitution Rate
Deletion of the I265-F268 and T271-K277 regions in the large lumenally exposed loop of the CP47 protein are known to lead to a loss of photoautotrophic growth. Here, these regions have been investigated by combinatorial mutagenesis and pseudorevertant mapping. No single amino-acid residue in the I265-F268 region was found to be critical for function, but a large hydrophobic residue at position 267 and preferentially an aromatic residue at position 268 appeared to be required for photoautotrophic growth. Starting from an obligate photoheterotrophic mutant lacking the T271-K277 region, photoautotrophic pseudorevertants were generated with short in-frame tandem repeats near the site of the original deletion, partially or fully restoring the length of the original protein. These pseudorevertants were sensitive to oxygen indicating that the T271-K277 region may provide PS II stability and/or protection against oxygen-dependent photoinactivation. Pseudorevertants with much improved photoautotrophic ...
Researchers assigned levels of risk to 25 mutations associated with breast and ovarian cancer in a large, Stanford-led study. The results may be helpful in guiding treatment and screening recommendations.
Researchers assigned levels of risk to 25 mutations associated with breast and ovarian cancer in a large, Stanford-led study. The results may be helpful in guiding treatment and screening recommendations.
Using real-time PCR to detect HIV resistance mutations present at low levels, Jeffrey Johnson and colleagues investigate prevalence and clinical implications of minority transmitted mutations.
BioMotiv, a drug development accelerator associated with The Harrington Project, and Rutgers, the State University of New Jersey, are announcing the formation of a new biotechnology startup, Z53 Therapeutics. Z53 Therapeutics aims to develop novel anti-cancer drugs that target tumors with p53 mutations.
Most truncation or deletion mutations underlying HI are thought to lead to severe loss of ABCA12 protein function affecting important nucleotide-binding fold domains and/or transmembrane domains. Thus far, in HI patients, at least one mutation on each allele must be a truncation or deletion mutation within a conserved region to cause serious loss of ABCA12. Complete loss of ABCA12 function due to homozygous or compound heterozygous truncation mutations always results in the HI patient phenotype. ...
Scientists make a DNA breakthrough by using multi-gene test to predict the risk of five diseases.. The key to prevention is identifying people who are at higher risk for diseases early on. Since most common diseases have a genetic component, we could start classifying people based on their genetic risk.. This is where genetic variants come into play. Genetic variants are small changes in DNA that exist between people, which can contribute to disease risk. However, most common diseases of today like heart disease and diabetes, are influenced by more than one gene.. Individually each gene only makes a small contribution towards disease risk. But when found together, they play a significant role in a persons genetic predisposition to disease. Unfortunately predicting disease risk based on multiple genes isnt an easy task.. However, according to ground breaking research published in the journal of Nature Genetics, this is no longer the case. Scientist can now effectively predict the risk of ...
The causes underlying racial disparities in cancer are multifactorial. In addition to socioeconomic issues, biological factors may contribute to these inequities, especially in disease incidence and patient survival. To date, there have been few studies that relate the disparities in these aspects to genetic aberrations. In this work, we studied the impacts of race on the patient survival and tumor mutation burden using the data released by the Cancer Genome Atlas (TCGA). The potential relationship between mutation burden and disease incidence is further inferred by an integrative analysis of TCGA data and the data from the Surveillance, Epidemiology, and End Results (SEER) Program. The results show that disparities are present (p | 0.05) in patient survival of five cancers, such as head and neck squamous cell carcinoma. The numbers of tumor driver mutations are differentiated (p | 0.05) over the racial groups in five cancers, such as lung adenocarcinoma. By treating a specific cancer type and a racial
Genetically modified mice are an essential tool for modeling disease-causing mechanisms and discovering gene function. SNP genotyping was traditionally used to associate candidate regions with traits in the mouse, but failed to reveal novel variants without further targeted sequencing. Using a robust set of computational protocols, we present a platform to enable scientists to detect variants arising from whole-genome and exome sequencing experiments. This article guides researchers on aligning reads to the mouse genome, quality-assurance strategies, mutation discovery, comparing mutations to previously discovered mouse SNPs, and the annotation of novel variants, in order to predict mutation consequences on the protein level. Challenges unique to the mouse are discussed, and two protocols use self-contained containers to maintain version control and allow users to adapt our approach to new techniques by upgrading container versions. Our protocols are suited for servers or office workstations and ...
Vorkas, P.A.; Poumpouridou, N.; Agelaki, S.; Kroupis, C.; Georgoulias, V.; Lianidou, E.S., 2010: PIK3CA hotspot mutation scanning by a novel and highly sensitive high-resolution small amplicon melting analysis method
This report describes mutants of the zebrafish having phenotypes causing a general arrest in early morphogenesis. These mutants identify a group of loci making up about 20% of the loci identified by mutants with visible morphological phenotypes within the first day of development. There are 12 Class I mutants, which fall into 5 complementation groups and have cells that lyse before morphological defects are observed. Mutants at three loci, speed bump, ogre and zombie, display abnormal nuclei. The 8 Class II mutants, which fall into 6 complementation groups, arrest development before cell lysis is observed. These mutants seemingly stop development in the late segmentation stages, and maintain a body shape similar to a 20 hour embryo. Mutations in speed bump, ogre, zombie, specter, poltergeist and troll were tested for cell lethality by transplanting mutant cells into wild-type hosts. With poltergeist, transplanted mutant cells all survive. The remainder of the mutants tested were autonomously but ...
Genetic mutations have two major types: large mutation (deletion, insertion, duplication, and inversion) and point mutation (nonsense, missense, and frame shift). Some mutations can induce DNA transcription and translation errors eventually causing protein dysfunction that leads to disease [1, 2]. Currently, many whole genome scale association studies between disease and variation are being published [3]. However, medical researchers have had to go through mutations in patient DNA to detect mutations that may be the cause of a disease [4, 5].. There are many human disease gene databases that contain disease-causing mutation information as locus-specific databases (LSDBs). Also, large databases, such as Online Mendelian Inheritance in Man (OMIM) [6] and the Human Gene Mutation Database (HGMD) [7], collect and describe comprehensively all disease-related genes. In contrast, LSDBs usually describe variations in a small number of genes. The LSDBs aim to provide particular genetic mutation ...
Seven single gene mutations are known to cause hypertension; this article guides clinicians through identification of the relatively uncommon defects, associated laboratory findings, and treatments.
The transcription factor CCAAT-enhancer-binding protein alpha (C/EBPα) is a master regulator of granulopoiesis and regulates the switch between proliferating, uncommitted progenitors and cell-cycle-arrested, differentiated myeloid cells. Usage of two alternative translation initiation sites in the CEBPA mRNA results in expression of a full-length C/EBPα protein p42 (42 kDa) and a shorter p30 isoform (30 kDa). CEBPA mutations are found in 9-15% of Acute Myeloid Leukemia (AML) patients. N-terminal frameshift mutations in the CEBPA gene lead to selective ablation of p42 expression, while C-terminal mutations disrupt the dimerization and DNA-binding ability of C/EBPα. AML patients harbor either mono- or biallelic CEBPA mutations (CEBPAmo or CEBPAbi) and both genotypes are frequently associated with concurrent mutations in other genes. The most commonly co-occurring mutations in both groups are loss-of-function mutations in the methylcytosine dioxygenase TET2 (44.4% in CEBPAmo / 34.8% in CEBPAbi). ...
From Jules: there was quite a bit of discussion at the workshop this year about using sensitive testing to identify low-level or minority genotypic resistance. At last years Resistance Workshop the CDC and Mike Kozal from Yale reported in oral presentations that minority mutations can lead to viral failure. Concerns are how to translate these potential concerns into the clinic. There are some lingering concerns among a few that further confirmation is required before presuming that the presence of low-level mutations is a reliable test for not using a drug, despite several studies reporting that the risk for viral failure significantly increases if these mutations are present; but not everyone fails if minority mutations are present, so are you throwing out a good drug by avoiding it? Still the studies so far presented find there is a significantly increased risk of viral failure. Tests to screen for minority mutations are not clinically available yest, as far as I know. But there were several ...
Ovarian and breast cancer can be either sporadic or hereditary. Sporadic cancers make up the vast majority (85-90%) of ovarian and breast cancers and are not associated with family history of either cancer or inherited cancer-associated mutations. Sporadic cancers arise from genetic mutations acquired in some cells of the body by events part of normal metabolism and environmental factors. This type of cancer can happen to anyone. Most acquired gene mutations are not shared among relatives or passed on to children.. Hereditary (also known as inherited, or familial) cancers are those that occur due to genetic mutations that are inherited from mom or dad. Other blood relatives may also share these same gene mutations. Parents give one copy of each gene to their children. If a parent has a genetic mutation in a gene, each of their children have a 50% chance of inheriting that mutation. Therefore, even in families with hereditary cancer, not all family members inherit the mutation that is causing ...
Mutation assays can then be grouped together into PCR arrays based off common themes to enable users to profile a focused set of mutations. The mutations on an array are selected based on a commonality, such as being from the same gene, signaling pathway, or cancer type. For example, users could profile the most common 84 mutations in breast cancer or the 44 most common mutations in APC. The Custom qBiomarker Somatic Mutation PCR Arrays allow users to select the mutations that they wish to profile. Together, the qBiomarker Somatic Mutation products facilitate sensitive detection and profiling of mutations in cancer cells or tumor samples ...
Purpose: : To identify and characterize the gene mutation responsible for photoreceptor degeneration in the rd3 mouse. Methods: : We screened genes in the known rd3 (RBF/DnJ) mapped region by direct sequencing. We additionally screened other rd3 lines (RBJ/Dn, STOCK Rb(11.13)4Bnr/J and STOCK In(5)30Rk) and normal mouse strains to verify the alteration. We carried out a mutation screen of the human RD3 gene in patients with retinopathies and examined 431 patients of Caucasian ethnicity and 103 of Asian-Indian ancestry. Amino acid changes that were identified in patients but not in controls are being examined by immunoblot analysis and immunocytochemisty to determine their effect(s) on protein stability or localization. Results: : The rd3 mutation is a homozygous C to T transition, leading to a stop codon, which is predicted to result in a premature truncation of the rd3 protein. The mutation was present in all rd3 lines tested (RBF/DnJ, RBJ/Dn, 4bnr and IN-30) but not in the control lines ...
Comprehensive mutational profiling data now available on all major cancers have led to proposals of novel molecular tumor classifications that modify or replace the established organ- and tissue-based tumor typing. The rationale behind such molecular reclassifications is that genetic alterations underlying cancer pathology predict response to therapy and may therefore offer a more precise view on cancer than histology. The use of individual actionable mutations to select cancers for treatment across histotypes is already being tested in the so-called basket trials with variable success rates. Here, we present a computational approach that facilitates the systematic analysis of the histological context dependency of mutational effects by integrating genomic and proteomic tumor profiles across cancers. To determine effects of oncogenic mutations on protein profiles, we used the energy distance, which compares the Euclidean distances of protein profiles in tumors with an oncogenic mutation (inner distance)
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TY - JOUR. T1 - Modeling post-translational modifications and cancer-associated mutations that impact the heterochromatin protein 1α-importin α heterodimers. AU - Zimmermann, Michael T.. AU - Williams, Monique M.. AU - Klee, Eric W. AU - Lomberk, Gwen A.. AU - Urrutia, Raul. PY - 2019/1/1. Y1 - 2019/1/1. N2 - Heterochromatin protein 1α (HP1α) is a protein that mediates cancer-associated processes in the cell nucleus. Proteomic experiments, reported here, demonstrate that HP1α complexes with importin α (IMPα), a protein necessary for its nuclear transport. This data is congruent with Simple Linear Motif (SLiM) analyses that identify an IMPα-binding motif within the linker that joins the two globular domains of this protein. Using molecular modeling and dynamics simulations, we develop a model of the IMPα-HP1α complex and investigate the impact of phosphorylation and genomic variants on their interaction. We demonstrate that phosphorylation of the HP1α linker likely regulates its ...
As climate change and population growth threaten to destabilize global food security, plant breeders are ramping up efforts to create better, more productive crops. But in order to introduce new traits, breeding techniques typically rely on rare genetic recombination events during meiosis.. Now, a study published in Nature Plants demonstrates that inactivating a single gene called RECQ4 can triple the number of recombination events during meiosis in a variety of distantly-related crop species, including rice (Oryza sativa), pea (Pisum sativum), and tomato (Solanum lycopersicum).. Such meiotic manipulation has been demonstrated before, but not in crop species. These mutations were around in Arabidopsis for several years. And then suddenly to see that this all works in crops. Thats fantastic, says Erik Wijnker, a plant biotechnologist at Wageningen University and Research in the Netherlands who was not involved in the study.. During meiosis, parental chromosomes move close enough to partially ...
All normal somatic cells are thought to acquire mutations, but understanding of the rates, patterns, causes and consequences of somatic mutations in normal cells is limited. The uterine endometrium adopts multiple physiological states over a lifetime and is lined by a gland-forming epithelium1,2. Here, using whole-genome sequencing, we show that normal human endometrial glands are clonal cell populations with total mutation burdens that increase at about 29 base substitutions per year and that are many-fold lower than those of endometrial cancers. Normal endometrial glands frequently carry driver mutations in cancer genes, the burden of which increases with age and decreases with parity. Cell clones with drivers often originate during the first decades of life and subsequently progressively colonize the epithelial lining of the endometrium. Our results show that mutational landscapes differ markedly between normal tissues-perhaps shaped by differences in their structure and physiology-and indicate
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The dominant paradigm for the evolution of mutator alleles in bacterial populations is that they spread by indirect selection for linked beneficial mutations when bacteria are poorly adapted. the first experimental evidence that direct selection can favour mutator alleles in bacterial populations, and pave the way for BEZ235 manufacturer future studies to understand how mutation and DNA repair are linked to stress responses and how this affects the evolution of bacterial mutation rates. mutant displays altered expression of a small number of housekeeping genes [16], raising the possibility that direct fitness costs and benefits may be associated with mutator alleles as a result of the pleiotropic effects of mutator alleles on gene expression. While the initial goal of this study was to investigate the interplay between BEZ235 manufacturer phenotypic and genetic changes in mutation rates in response to stress, preliminary findings led us to study the impact of direct stress-imposed selection on ...
Ilie, MI.; Lassalle, S.; Long-Mira, E.; Bonnetaud, C.; Bordone, O.; Lespinet, V.; Lamy, A.; Sabourin, JC. et al. (May 2014). Diagnostic value of immunohistochemistry for the detection of the BRAF(V600E) mutation in papillary thyroid carcinoma: comparative analysis with three DNA-based assays.. Thyroid 24 (5): 858-66. doi:10.1089/thy.2013.0302. PMID 24417277. ...
NSCLC-associated EGFR mutations are most frequently heterozygous. However, Paez et al. (18) reported one mutation involving exon 19 that appeared to be homozygous, and we detected two such cases. Interpretation of mutational status solely from DNA sequencing can be problematic. On the one hand, contaminating normal cells with wild-type EGFR could account for apparent heterozygosity; on the other hand, amplification of mutant EGFR, as occurs in lung cancer (23), could account for detection of only mutant sequences. Mouse models expressing mutant EGFR proteins in the lung and analysis of mutant-positive NSCLCs by fluorescence in situ hybridization and/or array-based comparative genomic hybridization may help address these issues. Interestingly, in one of these tumors (G3), we detected a heterozygous intronic polymorphism downstream of exon 19 (data not shown). In this case, it is probable that a gene conversion event occurred, encompassing the area of deletion in exon 19.. Five of 17 reported ...
Antibiotic resistance often evolves by mutations at conserved sites in essential genes, resulting in parallel molecular evolution between divergent bacterial strains and species. Whether these resistance mutations are having parallel effects on fitness across bacterial taxa, however, is unclear. This is an important point to address, because the fitness effects of resistance mutations play a key role in the spread and maintenance of resistance in pathogen populations. We address this idea by measuring the fitness effect of a collection of rifampicin resistance mutations in the β subunit of RNA polymerase (rpoB) across eight strains that span the diversity of the genus Pseudomonas We find that almost 50% of rpoB mutations have background-dependent fitness costs, demonstrating that epistatic interactions between rpoB and the rest of the genome are common. Moreover, epistasis is typically strong, and it is the dominant genetic determinant of the cost of resistance mutations. To investigate the functional
TY - JOUR. T1 - Trans-ancestry mutational landscape of hepatocellular carcinoma genomes. AU - Totoki, Yasushi. AU - Tatsuno, Kenji. AU - Covington, Kyle R.. AU - Ueda, Hiroki. AU - Creighton, Chad J.. AU - Kato, Mamoru. AU - Tsuji, Shingo. AU - Donehower, Lawrence A.. AU - Slagle, Betty L.. AU - Nakamura, Hiromi. AU - Yamamoto, Shogo. AU - Shinbrot, Eve. AU - Hama, Natsuko. AU - Lehmkuhl, Megan. AU - Hosoda, Fumie. AU - Arai, Yasuhito. AU - Walker, Kim. AU - Dahdouli, Mahmoud. AU - Gotoh, Kengo. AU - Nagae, Genta. AU - Gingras, Marie Claude. AU - Muzny, Donna M.. AU - Ojima, Hidenori. AU - Shimada, Kazuaki. AU - Midorikawa, Yutaka. AU - Goss, John A.. AU - Cotton, Ronald. AU - Hayashi, Akimasa. AU - Shibahara, Junji. AU - Ishikawa, Shumpei. AU - Guiteau, Jacfranz. AU - Tanaka, Mariko. AU - Urushidate, Tomoko. AU - Ohashi, Shoko. AU - Okada, Naoko. AU - Doddapaneni, Harsha. AU - Wang, Min. AU - Zhu, Yiming. AU - Dinh, Huyen. AU - Okusaka, Takuji. AU - Kokudo, Norihiro. AU - Kosuge, Tomoo. AU - ...
TY - JOUR. T1 - The mutational landscape of adenoid cystic carcinoma. AU - Ho, A.S.. AU - Kannan, K.. AU - Roy, D.M.. AU - Morris, L.G.T.. AU - Ganly, I.. AU - Katabi, N.. AU - Ramaswami, D.. AU - Walsh, L.A.. AU - Eng, S.. AU - Huse, J.T.. AU - Zhang, J.N.. AU - Dolgalev, I.. AU - Huberman, K.. AU - Heguy, A.. AU - Viale, A.. AU - Drobnjak, M.. AU - Leversha, M.A.. AU - Rice, C.E.. AU - Singh, B.. AU - Iyer, N.G.. AU - Leemans, C.R.. AU - Bloemena, E.. AU - Ferris, R.L.. AU - Seethala, R.R.. AU - Gross, B.E.. AU - Liang, Y.P.. AU - Sinha, R.. AU - Peng, L.K.. AU - Raphael, B.J.. AU - Turcan, S.. AU - Gong, Y.X.. AU - Schultz, N.. AU - Kim, S.. AU - Chiosea, S.. AU - Shah, JP. AU - Sander, C. AU - Lee, W.. AU - Chan, T.A.. PY - 2013. Y1 - 2013. U2 - 10.1038/ng.2643. DO - 10.1038/ng.2643. M3 - Article. VL - 45. SP - 791. EP - 798. JO - Nature Genetics. JF - Nature Genetics. SN - 1061-4036. IS - 7. ER - ...
Recent sequencing studies have extensively explored the somatic alterations present in the nuclear genomes of cancers. Although mitochondria control energy metabolism and apoptosis, the origins and impact of cancer-associated mutations in mtDNA are unclear. In this study, we analyzed somatic alterations in mtDNA from 1675 tumors. We identified 1907 somatic substitutions, which exhibited dramatic replicative strand bias, predominantly C | T and A | G on the mitochondrial heavy strand. This strand-asymmetric signature differs from those found in nuclear cancer genomes but matches the inferred germline process shaping primate mtDNA sequence content. A number of mtDNA mutations showed considerable heterogeneity across tumor types. Missense mutations were selectively neutral and often gradually drifted towards homoplasmy over time. In contrast, mutations resulting in protein truncation undergo negative selection and were almost exclusively heteroplasmic. Our findings indicate that the endogenous mutational
A research team, headed by Theodore Friedmann, MD, professor of pediatrics at the University of California, San Diego School of Medicine, says a gene mutation that causes a rare but devastating neurological disorder known as Lesch-Nyhan syndrome appears to offer clues to the developmental and neuronal defects found in other, diverse neurological disorders like Alzheimers, Parkinsons and Huntingtons diseases. The findings, published in the October 9, 2013 issue of the journal PLOS ONE, provide the first experimental picture of how gene expression errors impair the ability of stem cells to produce normal neurons, resulting instead in neurological disease. More broadly, they indicate that at least some distinctly different neurodevelopmental and neurodegenerative disorders share basic, causative defects. The scientists say that understanding defects in Lesch-Nyhan could help identify errant processes in other, more common neurological disorders, perhaps pointing the way to new kinds of ...
The morphological features of tumors are closely related to their growth patterns [8]. Polypoid tumors are believed to exhibit a predominantly vertical growth pattern, rather than a horizontal growth pattern, while non-polypoid tumors are believed to exhibit the opposite pattern, resulting in horizontal growth. Although there are some reports that LSTs have distinct biological characteristics compared to polypoid tumors [9, 10], the mechanism by which the LST conformation is generated remains unknown.. LSTs are believed to have distinct characteristics in terms of histological and genetic features [11]. Several molecular characteristics of LSTs have been described, including alteration of the adenomatous polyposis coli (APC) gene or β-catenin [12-14] affecting the WNT/APC/β-catenin signaling pathway, mutation of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) [12, 15-20]. However, the molecular background of LSTs has remained largely unknown [19, 21]. Most of these studies have ...
Somatic genetic mutation in the V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) gene has been linked to poor prognosis and resistance to various targeted therapeutics in Non Small Cell Lung Cancer (NSCLC). Therapeutic strategies that target tumors harboring these mutations represent an unmet medical need. In this study, we investigated the relationship between antifolate sensitivity and KRAS mutation/amplification status in NSCLC.. Human NSCLC cell lines (KRAS wild type, KRAS mutant non-amplified and KRAS mutant amplified) were treated with Methotrexate (MTX) or Pemetrexed (PEM) and assayed for proliferation after 72h. In these studies, 5 out of 7 KRASwt (wildtype) cells and all KRASmut (mutant) amplified cells showed resistance to MTX treatment (IC50 ,10μM). In contrast, growth of all KRASmut non-amplified cell lines studied was inhibited with MTX treatment (IC50 ,100nM). Similar effects were observed for PEM in this study. Interrogation of the NCI Developmental Therapeutics ...
This charge from a basic to an uncharged amino acid is probably consistent with disease and the mutation occurs at a CG dinucleotide, a known mutation hot spot. This mutation was detected in 2 sibs with CF and is associated with an X2 K1 haplotype, the other mutation in this family is also on a X2 K1 haplotype and is undefined. In the original report, R297Q was not detected in a further 54 CF chromosomes with an unidefined mutations and 50 normal chromosomes, all samples were of Northern Irish origin. Dubourg argued that R297Q is a rare polymorphism rather than a deleterious mutation as usually reported. The first supportive evidence came from a family where R297Q was associated with two of the most severe molecular defects DF508 or N1303K on healthy subjects (DORVAL, JEZEQUEL, CHAUVEL, DUBOURG et al. (1995) Human Mutation, 6 : 334-335). More recently, Dubourg et al. identified the same aminoacid change (R297Q) in association with the 574delA mutation in an healthy subject. (Christèle DUBOURG, ...
To date, approximately 70%-80% of XLRP cases are found to carry mutations in RPGR and up to 20% are found to carry mutations in RP2 [10]. The exon ORF15, which contains a purine-rich domain of an approximately 1706-bp coding sequence and is predicted to encode a repetitive glycine and glutamate region at the C-terminus of the protein, is a mutation hot spot for XLRP [12]. Between 30% and 80% of RPGR mutations are identified in exon ORF15, followed by mutation frequencies that are similar for RP2 and RPGR exons 1-15 [11-13,24-28]. No mutation has yet been identified in exons 16-19. Based on these results and to keep costs low, Neidhardt and coworkers proposed a screening strategy for routine molecular genetics testing of XLRP cases by direct sequencing and recommended beginning with the screening of an XLRP male patient by ORF15 mutation analysis [14]. After identification of an ORF15 mutation, the molecular diagnosis is considered confirmed since patients with an additional mutation in exons 1 ...
Looking for natural mutation? Find out information about natural mutation. A mutation that occurs spontaneously, that is, in an individual not specifically exposed to a known mutagen Explanation of natural mutation
Methods We designed a high-throughput sequencing panel to identify variants in 15 genes (7 known SVD genes, 8 SVD-related disorder genes). The panel was used to screen a population of 950 patients with younger-onset (≤70 years) MRI-confirmed SVD stroke, recruited from stroke centers across the United Kingdom. Variants were filtered according to their frequency in control databases, predicted effect, presence in curated variant lists, and combined annotation dependent depletion scores. Whole genome sequencing and genotyping were performed on a subset of patients to provide a direct comparison of techniques. The frequency of known disease-causing and pertinent variants of uncertain significance was calculated. ...
When the DNA polymerase that replicates the Escherichia coli chromosome, DNA polymerase III, makes an error, there are two primary defenses against mutation: proofreading by the ϵ subunit of the holoenzyme and mismatch repair. In proofreading-deficient strains, mismatch repair is partially saturated and the cells response to DNA damage, the SOS response, may be partially induced. To investigate the nature of replication errors, we used mutation accumulation experiments and whole-genome sequencing to determine mutation rates and mutational spectra across the entire chromosome of strains deficient in proofreading, mismatch repair, and the SOS response. We report that a proofreading-deficient strain has a mutation rate 4000-fold greater than wild-type strains. While the SOS response may be induced in these cells, it does not contribute to the mutational load. Inactivating mismatch repair in a proofreading-deficient strain increases the mutation rate another 1.5-fold. DNA polymerase has a bias for
The qBiomarker Somatic Mutation PCR Assays are a fast and reliable mutation analysis tool using ARMS® (Amplification Refractory Mutation System) primer-based allele discrimination and Hydrolysis Probe-based quantitative real-time PCR technology. It utilizes a proprietary and experimentally verified algorithm for designing mutation-specific qPCR primers and probe. Each qBiomarker Somatic Mutation PCR Assay is subjected to rigorous experimental verification. Both sensitive detection of the intended mutation in a sample (as low as 1% mutant sample on a wild-type sample background) and assay specificity (i.e. discrimination between mutant sample and wild-type sample) are guaranteed when used with the qBiomarker Probe Master Mix. A gene-specific reference assay for checking sample quality and measuring sample input and gene copy dosage is included for each mutation assay. See the qBiomarker Somatic Mutation PCR Array System User Manual/ Handbook for protocol to follow.. The qBiomarker Somatic ...
The qBiomarker Somatic Mutation PCR Assays are a fast and reliable mutation analysis tool using ARMS® (Amplification Refractory Mutation System) primer-based allele discrimination and Hydrolysis Probe-based quantitative real-time PCR technology. It utilizes a proprietary and experimentally verified algorithm for designing mutation-specific qPCR primers and probe. Each qBiomarker Somatic Mutation PCR Assay is subjected to rigorous experimental verification. Both sensitive detection of the intended mutation in a sample (as low as 1% mutant sample on a wild-type sample background) and assay specificity (i.e. discrimination between mutant sample and wild-type sample) are guaranteed when used with the qBiomarker Probe Master Mix. A gene-specific reference assay for checking sample quality and measuring sample input and gene copy dosage is included for each mutation assay. See the qBiomarker Somatic Mutation PCR Array System User Manual/ Handbook for protocol to follow.. The qBiomarker Somatic ...
Design To show a HR advantage of 0.6 in progression-free survival (PFS) for FCGR2A-HH versus the rest and FCGR3A-VV versus the rest, with an 80% power, 80 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) wild-type (KRAS-WT) and 52 KRAS-WT patients are required, respectively. This leads to a total sample size of 952 and 619 patients, respectively. Samples were collected from 1123 mCRC patients from 15 European centres treated with cetuximab alone or in combination with chemotherapy. Fc gamma receptor (FCGR) status was centrally genotyped. Two additional externally genotyped series were included. ...
QUESTION: There is a genetic component to Alzheimers. Yet, genetic markers for Alzheimers have yet to be identified. What makes Alzheimers so complex that it is extremely difficult to find genetic and biomarkers and treatment for the disease?. ANSWER: AD is most likely due to a combination of genetic susceptibility and environmental influence. Early-onset AD is a rare form of AD, affecting only about 5 percent of all people who have AD. It develops in people ages 30 to 60.. Some cases of early-onset AD, called familial AD (FAD), are inherited. FAD is caused by a number of different gene mutations on chromosomes 21, 14, and 1, and each of these mutations causes abnormal proteins to be formed. Mutations on chromosome 21 cause the formation of abnormal amyloid precursor protein (APP). A mutation on chromosome 14 causes abnormal presenilin 1 to be made, and a mutation on chromosome 1 leads to abnormal presenilin 2.. Even if only one of these mutated genes is inherited from a parent, the person ...
Activating mutations in the PIK3CA gene have been identified in a variety of human malignancies and are commonly detected in hotspot codons located in the helical and kinase domains in exons 9 and 20. Existing methodologies for the detection of PIK3CA mutations are time-consuming and/or expensive. In the present study we describe the first application of a PIK3CA SNaPshot assay to the screening of frequent mutations in these exons. A SNaPshot assay for the simultaneous detection of four frequent PIK3CA hotspot mutations (E542K, E545G, E545K and H1047R) has been developed and evaluated. The assay combines multiplex PCR amplification with a multiplex primer extension assay to allow targeted detection of all four mutations in one reaction. The method was tested using samples that had previously been analysed for mutations by high-resolution melting analysis and sequencing. All mutations detected were concordant and no false positive results were obtained. Sensitivity tests showed that the SNaPshot assay
Primary pulmonary enteric adenocarcinoma (PEAC) is an extremely rare variant of invasive lung cancer. It is highly heterogeneous while shares some common morphologic and immunohistochemical features with usual pulmonary adenocarcinoma (PAC) and colorectal adenocarcinoma (CRAC), making the differential diagnosis difficult. At present there are only limited studies about distinctive features of primary PEAC and the results are often inconsistent. We retrospectively analyzed total 129 primary PEACs and 50 CRACs that were published since 1991 or diagnosed in our centre. Among them eight typical samples of primary PEACs and usual PACs were detected by targeted exome sequencing. The combination of CK7+/CDX2+ acquires high sensitivity (71.3%) and specificity (82%) in differential diagnosis of PEACs from CRAC. The primary PEACs harbor a high incidence of KRAS mutation but almost absent of EGFR mutation. Moreover, compared with usual PACs, the primary PEACs have higher nonsynonymous tumor mutation burden and
Primary pulmonary enteric adenocarcinoma (PEAC) is an extremely rare variant of invasive lung cancer. It is highly heterogeneous while shares some common morphologic and immunohistochemical features with usual pulmonary adenocarcinoma (PAC) and colorectal adenocarcinoma (CRAC), making the differential diagnosis difficult. At present there are only limited studies about distinctive features of primary PEAC and the results are often inconsistent. We retrospectively analyzed total 129 primary PEACs and 50 CRACs that were published since 1991 or diagnosed in our centre. Among them eight typical samples of primary PEACs and usual PACs were detected by targeted exome sequencing. The combination of CK7+/CDX2+ acquires high sensitivity (71.3%) and specificity (82%) in differential diagnosis of PEACs from CRAC. The primary PEACs harbor a high incidence of KRAS mutation but almost absent of EGFR mutation. Moreover, compared with usual PACs, the primary PEACs have higher nonsynonymous tumor mutation burden and
Somatic mutations in epigenetic enzymes are frequently found in cancer tissues. The MLL3 H3K4-specific protein lysine monomethyltransferase is an important epigenetic enzyme, and it is among the most recurrently mutated enzymes in cancers. MLL3 mainly introduces H3K4me1 at enhancers. We investigated the enzymatic properties of MLL3 variants that carry somatic cancer mutations. Asn4848 is located at the cofactor binding sites, and the N4848S exchange renders the enzyme inactive. Tyr4884 is part of an aromatic pocket at the active center of the enzyme, and Y4884C converts MLL3 from a monomethyltransferase with substrate preference for H3K4me0 to a trimethyltransferase with H3K4me1 as preferred substrate. Expression of Y4884C leads to aberrant H3K4me3 formation in cells. Our data show that different somatic cancer mutations of MLL3 affect the enzyme activity in distinct and opposing manner highlighting the importance of experimentally studying the effects of somatic cancer mutations in key regulatory
Somatic mutations in epigenetic enzymes are frequently found in cancer tissues. The MLL3 H3K4-specific protein lysine monomethyltransferase is an important epigenetic enzyme, and it is among the most recurrently mutated enzymes in cancers. MLL3 mainly introduces H3K4me1 at enhancers. We investigated the enzymatic properties of MLL3 variants that carry somatic cancer mutations. Asn4848 is located at the cofactor binding sites, and the N4848S exchange renders the enzyme inactive. Tyr4884 is part of an aromatic pocket at the active center of the enzyme, and Y4884C converts MLL3 from a monomethyltransferase with substrate preference for H3K4me0 to a trimethyltransferase with H3K4me1 as preferred substrate. Expression of Y4884C leads to aberrant H3K4me3 formation in cells. Our data show that different somatic cancer mutations of MLL3 affect the enzyme activity in distinct and opposing manner highlighting the importance of experimentally studying the effects of somatic cancer mutations in key regulatory
Kras: | |GTPase KRas| also known as |V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog| a... World Heritage Encyclopedia, the aggregation of the largest online encyclopedias available, and the most definitive collection ever assembled.
Mutation and recombination are central processes driving microbial evolution. A high mutation rate fuels adaptation but also generates deleterious mutations. Recombination between two different genomes may resolve this paradox, alleviating effects of clonal interference and purging deleterious mutations. Here we demonstrate that recombination significantly accelerates adaptation and evolution during acute virus infection. We identified a poliovirus recombination determinant within the virus polymerase, mutation of which reduces recombination rates without altering replication fidelity. By generating a panel of variants with distinct mutation rates and recombination ability, we demonstrate that recombination is essential to enrich the population in beneficial mutations and purge it from deleterious mutations. The concerted activities of mutation and recombination are key to virus spread and virulence in infected animals. These findings inform a mathematical model to demonstrate that poliovirus ...
The fluoroquinolones (FQs) are synthetic antibiotics effectively used for curing patients with multidrug-resistant tuberculosis (TB). When a multidrug-resistant strain develops resistance to the FQs, as in extensively drug-resistant strains, obtaining a cure is much more difficult, and molecular methods can help by rapidly identifying resistance-causing mutations. The only mutations proven to confer FQ resistance in M. tuberculosis occur in the FQ target, the DNA gyrase, at critical amino acids from both the gyrase A and B subunits that form the FQ binding pocket. GyrA substitutions are much more common and generally confer higher levels of resistance than those in GyrB. Molecular techniques to detect resistance mutations have suboptimal sensitivity because gyrase mutations are not detected in a variable percentage of phenotypically resistant strains. The inability to find gyrase mutations may be explained by heteroresistance: bacilli with a resistance-conferring mutation are present only in a ...
The emergence of drug resistance remains a major problem for the treatment of HIV-infected patients. However, the variety of mutational patterns that evolve in clinical practice have made the application of resistance data to clinical decision-making challenging. Despite (or because of) an abundance of drug-resistance data from disparate sources, there is only limited information available describing the patterns of drug resistance which usually appear in the clinic.
Interpreting cancer mutations is a complex task as only few mutations are cancer drivers while most are functionally inactive passengers (6). We can improve driver discovery by focusing on mutations in small sites involved in interactions of networks, as these mutations are more likely important in cancer. We used this idea to build the mutation enrichment model ActiveDriver (7) that analyses mutations in protein sites of post-translational modifications (PTMs). PTMs such as phosphorylation are involved in cellular signalling and cancer pathways. We applied ActiveDriver in the TCGA pan-cancer project to characterise the mutational landscape of signalling networks and to detect known and candidate cancer driver genes (8,9). In another study, we analysed population-wide genome variation and found that PTM sites are strongly conserved among humans and enriched in germline disease variants, emphasizing their importance in physiology and predisposition to disease (10). We recently developed the ...
Interpreting cancer mutations is a complex task as only few mutations are cancer drivers while most are functionally inactive passengers (6). We can improve driver discovery by focusing on mutations in small sites involved in interactions of networks, as these mutations are more likely important in cancer. We used this idea to build the mutation enrichment model ActiveDriver (7) that analyses mutations in protein sites of post-translational modifications (PTMs). PTMs such as phosphorylation are involved in cellular signalling and cancer pathways. We applied ActiveDriver in the TCGA pan-cancer project to characterise the mutational landscape of signalling networks and to detect known and candidate cancer driver genes (8,9). In another study, we analysed population-wide genome variation and found that PTM sites are strongly conserved among humans and enriched in germline disease variants, emphasizing their importance in physiology and predisposition to disease (10). We recently developed the ...
What are some restrictive conditions of the respiratory system? Visit HowStuffWorks to learn more about the respiratory system and some restrictive conditions of the respiratory system.
TY - JOUR. T1 - CAPN5 mutation in hereditary uveitis. T2 - The R243L mutation increases calpain catalytic activity and triggers intraocular inflammation in a mouse model. AU - Wert, Katherine J.. AU - Bassuk, Alexander G.. AU - Wu, Wen Hsuan. AU - Gakhar, Lokesh. AU - Coglan, Diana. AU - Mahajan, Mary Ann. AU - Wu, Shu. AU - Yang, Jing. AU - Lin, Chyuan Sheng. AU - Tsang, Stephen H.. AU - Mahajan, Vinit B.. PY - 2015/4/28. Y1 - 2015/4/28. N2 - A single amino acid mutation near the active site of the CAPN5 protease was linked to the inherited blinding disorder, autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV, OMIM #193235). In homology modeling with other calpains, this R243L CAPN5 mutation was situated in a mobile loop that gates substrate access to the calcium-regulated active site. In in vitro activity assays, the mutation increased calpain protease activity and made it far more active at low concentrations of calcium. To test whether the disease allele could yield an ...
Loss of sex and recombination is generally assumed to impede the effectiveness of purifying selection and to result in the accumulation of slightly deleterious mutations. Empirical evidence for this has come from several studies investigating mutational load in a small number of individual genes. However, recent whole transcriptome based studies have yielded inconsistent results, hence questioning the validity of the assumption of mutational meltdown in asexual populations. Here, we study the effectiveness of purifying selection in eight asexual hexapod lineages and their sexual relatives, as present in the 1 K Insect Transcriptome Evolution (1KITE) project, covering eight hexapod groups. We analyse the accumulation of slightly deleterious nonsynonymous and synonymous point mutations in 99 single copy orthologue protein-coding loci shared among the investigated taxa. While accumulation rates of nonsynonymous mutations differed between genes and hexapod groups, we found no effect of reproductive mode on
References. Brosh, R., and Rotter, V. (2009). When mutants gain new powers: news from the mutant p53 field. Nat Rev Cancer 9, 701-713.. Dittmer, D., Pati, S., Zambetti, G., Chu, S., Teresky, A. K., Moore, M., Finlay, C., and Levine, A. J. (1993). Gain of function mutations in p53. Nat Genet 4, 42-46.. Gualberto, A., Aldape, K., Kozakiewicz, K., and Tlsty, T. D. (1998). An oncogenic form of p53 confers a dominant, gain-of-function phenotype that disrupts spindle checkpoint control. Proc Natl Acad Sci U S A 95, 5166-5171.. Lang, G. A., Iwakuma, T., Suh, Y. A., Liu, G., Rao, V. A., Parant, J. M., Valentin-Vega, Y. A., Terzian, T., Caldwell, L. C., Strong, L. C., El-Naggar, A. K., and Lozano, G. (2004). Gain of function of a p53 hot spot mutation in a mouse model of Li-Fraumeni syndrome. Cell 119, 861-872.. Olive, K. P., Tuveson, D. A., Ruhe, Z. C., Yin, B., Willis, N. A., Bronson, R. T., Crowley, D., and Jacks, T. (2004). Mutant p53 gain of function in two mouse models of Li-Fraumeni syndrome. Cell ...
Suggest two methods to isolate a collection of cold-sensitive mutants in Salmonella typhimurium -- that is, mutants that grow at 42 C but do not grow at 30 C.. ANSWER: Although conditional mutations may not grow at the nonpermissive temperature, they often survive short exposure to the nonpermissive temperature. With this hint, consider the three basic approaches for isolating mutants: selections, screens, and enrichments. There is no obvious way of selecting for the desired mutants because the desired mutation is unable to grow under the nonpermissive conditions. It would be straightforward to screen for the desired mutants -- for example, (i) you could plate colonies at 30 C, replica plate the colonies to 30 C and 42 C, then look for colonies that grow at 42 C but not at 30 C, or (ii) you could plate the cells at the nonpermissive temperature for a short time then shift the plates to the permissive temperature -- the mutants usually form smaller colonies due to the effect of the temporary ...
A high mutational load and the presence of a T-cell-inflamed environment may independently predict for treatment response to pembrolizumab (Keytruda) and progression-free survival, according to a study presented by Tanguy Seiwert, MD, of the University of Chicago, at the 2017 ASCO-SITC Clinical Immuno-Oncology Symposium.1. Nonsynonymous mutational load and neoantigen load as well as an 18-gene immune-related gene-expression profiling were significantly associated with overall response and progression-free survival to pembrolizumab across multiple indications, Dr. Seiwert revealed. This suggests that tumor antigenicity and T-cell infiltration may provide complementary information for expected pembrolizumab activity and may be useful in characterizing responses to immunotherapies, he said.. Tumor mutational load has been shown to correlate with benefit from drugs blocking cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) in multiple tumor types. ...
Three temperature-sensitive S. cerevisiae RFA1 alleles were found to cause elevated mutation rates. These mutator phenotypes resulted from the accumulation of base substitutions, frameshifts, gross deletions (8 bp-18 kb), and nonreciprocal translocations. A representative rfa1 mutation exhibited a g …
With direct sanger sequencing, FemtoPath PTEN Mutation Screen Kit is able to detect somatic mutation from DNA derived from formalin-fixed paraffin-embedded (FFPET), fine needle biopsy or pleural effusion specimens.. The feature of FemtoPath mutation screen kit ...
Mutations[edit]. Figure 3. Effects on TBP binding to the TATA box from mutations. Wildtype shows transcription done normally. ... Point mutations[edit]. Point mutations to the TATA box have similar varying phenotypic changes depending on the gene that is ... Mutations to the TATA box can range from a deletion or insertion to a point mutation with varying effects based on the gene ... Based on the sequence and mechanism of TATA box initiation, mutations such as insertions, deletions, and point mutations to ...
Defining mutations. M242. Highest frequencies. Kets 93.8%,[6] Turkmens 73%,[7] Selkups 66.4%.,[6] Altaians 63.6%.,[8] Tuvans ... Technical specification of mutation[edit]. The technical details of M242 are: Nucleotide change: C to T. Position (base pair): ... The subclades of Haplogroup Q-M242 with their defining mutation (s), according to the 2015 ISOGG tree[4] are provided below. ... Human Mutation. 24 (3): 248-60. doi:10.1002/humu.20077. PMID 15300852.. Q-M323 in 3/20=15% of a sample of Yemenite Jews. ...
75 to 80 percent of Leigh syndrome is caused by mutations in nuclear DNA; mutations affecting the function or assembly of the ... The most common MT-ATP6 mutation found with Leigh syndrome is a point mutation at nucleotide 8993 that changes a thymine to a ... Mutations in mitochondrial DNA (mtDNA) and over 30 genes in nuclear DNA (gene SURF1[8] and some COX assembly factors) have been ... Mitochondrial DNA mutations[edit]. Mitochondria are essential organelles in eukaryotic cells. Their function is to convert the ...
Consonant mutation[edit]. Another feature of the language is initial consonant mutation between singular and plural forms of ... nouns and of verbs (except in Pular, there is no consonant mutation in verbs, only in nouns). ...
Initial mutations[edit]. Main article: Irish initial mutations. In Irish, there are two classes of initial consonant mutations ... Due to initial mutation, prefixes, clitics, suffixes, root inflection, ending morphology, elision, sandhi, epinthesis, and ... Mutations are often the only way to distinguish grammatical forms. For example, the only non-contextual way to distinguish ... possessive pronouns "her," "his" and "their", is through initial mutations since all meanings are represented by the same word ...
Rare mutations[edit]. Women with CAIS, who are completely insensitive to the AR-mediated actions of androgens, have, as a group ...
MDR1 gene mutation[edit]. Recent research at Washington State University indicates that, in addition to many other herding ... breeds, approximately 15% of the English Shepherd population is subject to the MDR1 gene mutation. Dogs that are tested ...
EGFR mutations[edit]. Roughly 10-35% of people who have NSCLC will have drug sensitizing mutations of the EGFR.[43] The ... likely cause the high level of mutation in lung cancer cells of more than 100,000 mutations per genome (see Whole genome ... Several studies have also shown that ALK mutations and EGFR activating mutations are typically mutually exclusive. Thus, it is ... People with these mutations are more likely to have adenocarcinoma histology and be non-smokers or light smokers. These people ...
Mutation[edit]. Whole genome sequencing has established the mutation frequency for whole human genomes. The mutation frequency ... Cause of mutations[edit]. The likely major underlying cause of mutations in carcinomas is DNA damage.[13] For example, in the ... The high mutation frequencies in carcinomas reflect the genome instability characteristic of cancers.[citation needed] ... While a mutation or epimutation in a DNA repair gene, itself, would not confer a selective advantage, such a repair defect may ...
Mutations[edit]. Panem uses genetic engineering to create animals which figure into the Hunger Games or otherwise serve its ... part-human mutations during the second rebellion, so that he could save Katniss's life. This results in Annie being the only ...
Mutation breeding[edit]. Conventional hybridization is difficult to carry out in roselle due to its cleistogamous nature of ... Because of this, a mutation breeding programme was initiated to generate new genetic variability.[21] The use of induced ... Roselle improvement through conventional and mutation breeding. Proc. Intern. Nuclear Conf. 2002, 15-18 Oct 2002, Kuala Lumpur ... These new varieties were developed using Arab as the parent variety in a mutation breeding programme which started in 2006. ...
Sports (mutations)[edit]. Many sports of Gala have been selected, mostly for increased red color, including the popular Royal ...
Mitochondrial mutations in disease[edit]. See also: Mitochondrial diseases. Mutations in mitochondrial DNA are usually single ... This refers to hundreds of independent mutations in one organism, with each mutation found in about 1-2% of all mitochondrial ... In most cases, a muscle mutation level of approximately 18% or less confers a 95% risk reduction.[12] ... Additionally, there is a dose-dependent decrease in reproduction ability for females that have mutations in mitochondrial DNA. ...
Mutation mechanisms and mutation rates[edit]. DNA strand slippage during replication of an STR locus. Boxes symbolize ... Unlike point mutations, which affect only a single nucleotide, microsatellite mutations lead to the gain or loss of an entire ... Microsatellite mutation rates[edit]. Microsatellite mutation rates vary with base position relative to the microsatellite, ... Thus, the mutation rate at microsatellite loci is expected to differ from other mutation rates, such as base substitution rates ...
Deleterious mutation clearance[edit]. Mutations can have many different effects upon an organism. It is generally believed that ... Once a mutation occurs in the DNA or other genetic carrying sequence, there is no way for the mutation to be removed from the ... The next mutation that occurs turns the ratchet once more. Additional mutations in a population continually turn the ratchet ... Muller described this occurrence by comparing the mutations that accumulate as a ratchet. Each mutation that arises in ...
b: black- The black mutation was discovered in 1910 by Thomas Hunt Morgan.[48] The black mutation results in a darker colored ... y: yellow- The yellow gene is a genetic mutation known as Dmel\y within the widely used data base called flybase. This mutation ... It is caused by mutations in the gene WRN that encodes a protein with essential roles in repair of DNA damage. Mutations in the ... due to a point mutation on chromosome II.[51] When the mutation is homozygous, the pteridine pigments are unable to be ...
Mutations[edit]. Approximately four hundred type X Charcot-Marie-Tooth causing mutations have been identified within the GJB1 ... Some of these mutations also cause hearing loss in patients with CMTX.[14] Currently it is unknown how the mutations of the ... Most of the mutations of the GJB1 gene switch or change a single amino acid in the gap junction (connexin-32) protein, although ... With the creation of genetic testing, 90% of CMTX cases are now diagnosed using the mutations of the GJB1 (Cx32) gene.[11] The ...
Mutations[edit]. In 2018 scientists from the University of Portsmouth with the collaboration of the National Renewable Energy ...
COD has been linked to several genetic mutations including mutations in the guanylate cyclase activator 1A (GUCA1A) and ... Mutations[edit]. Cone dystrophy (COD) is a retinal degradation of photoreceptor function wherein cone function is lost at the ... 2011). "Mutation analysis at codon 838 of the guanylate cycllase 2D gene in spanish families with autosomal dominant cone, cone ... Therefore, mutations in the RETGC-1 can cause COD by increasing intracellular calcium levels and stimulating cone photoreceptor ...
Genetic mutations occur when nucleotide sequences in an organism are altered. These mutations lead to not only observable ... The sources for these mutations can be errors during replication, spontaneous mutations, and chemical and physical mutagens (UV ... Mutations in polycomb-group response elements (PREs)[edit]. The Polycomb-group (PcG) regulatory complexes are known for their ... A mutation in either the NRSF or NRSE can lead to an undesirable development of ventricular myocytes, due to lack of repression ...
Gene mutations[edit]. Genetic mutations and chromosomal abnormalities are two sources of HPG axis alteration.[15] Single ... For example, the male mutation of the GnRH coding gene could result in hypogonadotrophic hypogonadism. A mutation that cause a ... These mutations can occur in the genes coding for GnRH, LH, and FSH or their receptors. Depending on which hormone and receptor ... In females mutations would have analogous effects. Hormone replacement can be used to initiate puberty and continue if the gene ...
In this mutation, the adult male is melanistic with black wings.[8][12] Young birds with the nigripennis mutation are creamy ... Mutations and hybrids[edit]. A white peafowl that is maintained by selective breeding in many parks such as this one at the ... The black-shouldered or Japanned mutation was initially considered as a subspecies P. c. nigripennis (or even a species),[11] ... There are several colour mutations of Indian peafowl. These very rarely occur in the wild, but selective breeding has made them ...
Most mutations have little effect on an organism's phenotype, health, or reproductive fitness.[76] Mutations that do have an ... Mutations occasionally occur within cells in the body as they divide. Although these mutations will not be inherited by any ... Figure (2) shows a missense, single point, non silent mutation. Figures (3 and 4) both show frameshift mutations, which is why ... somatic mutations). The most frequent mutations are a loss of function of p53 protein, a tumor suppressor, or in the p53 ...
a b Sanjuán R, Nebot MR, Chirico N, Mansky LM, Belshaw R. Viral mutation rates. Journal of Virology. 2010;84(19):9733-48. doi: ... Shuda M, Feng H, Kwun HJ, Rosen ST, Gjoerup O, Moore PS, Chang Y. T antigen mutations are a human tumor-specific signature for ... However, viruses are not classified on the basis of phylum or class, as their small genome size and high rate of mutation makes ... Most of these point mutations are "silent" - they do not change the protein that the gene encodes - but others can confer ...
High mutation rate[edit]. Influenza viruses have a relatively high mutation rate that is characteristic of RNA viruses. The ... Three mutations were introduced into the H5N1 virus genome, and the virus was then passed from the noses of infected ferrets to ... Mutations occurring within this genotype are increasing their pathogenicity.[66] Birds are also able to shed the virus for ... Genetic mutations in the hemagglutinin gene that cause single amino acid substitutions can significantly alter the ability of ...
Variegated mutation[edit]. There is also a variegated mutation of the regular calamansi, showing green stripes on yellow fruit. ...
High mutation rate[edit]. 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 risk of mutation than the rest of the genome.[16] The increased ... Thus, although a male may have a well adapted Y chromosome free of excessive mutation, it may never make it in to the next gene ... Even if a well adapted Y chromosome manages to maintain genetic activity by avoiding mutation accumulation, there is no ...
Gene mutations[edit]. Several gene mutations have been identified in patients with camptocormia. These include the RYR1 gene in ...
Consonant mutation[edit]. Celtic languages[edit]. See also: Irish initial mutations § Changes to vowel-initial words ...
Mutations and clinical significance[edit]. A mutation in the NOBOX gene is associated with premature ovarian failure (POF), ... However, these mutations were not found in Chinese and Japanese women making it a less common explanation for POF in the region ... Several NOBOX loss-of-function mutations were observed in Caucasian and African women accounting to 6.2%, 5.6% and 6.4%.[11][21 ... Qin Y, Shi Y, Zhao Y, Carson SA, Simpson JL, Chen ZJ (April 2009). "Mutation analysis of NOBOX homeodomain in Chinese women ...
These mutations can be passed down genetically and either be lost or become fixed. Since mutation usually affects a single ... To connect the idea of mutations back to our discussion of DNA and proteins, here are some examples of how a mutation in the ... Finally, a common mutation in humans causes red blood cells to be shaped in a sickle pattern as shown above on the upper left. ... A mutation in these garden moss roses (shown in the left) has caused some of the flowers to grow orange rather than yellow. ...
A suppressor mutation is a second mutation that alleviates or reverts the phenotypic effects of an already existing mutation in ... suppression relieves the effects of a mutation in one gene by a mutation somewhere else within the genome. The second mutation ... Intragenic suppression results from suppressor mutations that occur in the same gene as the original mutation. In a classic ... Genetic suppression therefore restores the phenotype seen prior to the original background mutation.[1] Suppressor mutations ...
... with BRCA1 mutations being slightly more common than BRCA2 mutations), but the impact on women with the gene mutation is more ... A BRCA mutation is a mutation in either of the BRCA1 and BRCA2 genes, which are tumour suppressor genes. Hundreds of different ... There is likely little or no effect of a BRCA gene mutation on overall fertility,[17] although women with a BRCA mutation may ... Mutations in BRCA1 and BRCA2 are strongly implicated in some hematological malignancies. BRCA1 mutations are associated acute ...
"mutation" in le Trésor de la langue française informatisé (The Digitized Treasury of the French Language). ... Names for a group: A flute or mutation of thrushes.. *2013, Jason Sacher, A Compendium of Collective Nouns: From an Armory of ... From Middle French mutation, from Old French mutacion, borrowed from Latin mutatio, mutationem. ... A Mutation of Thrushes. The authors of the books of venery were not predicting Darwin with this term, but taking a cue from a ...
... mutation refers to any sudden change in DNA-deoxyribonucleic acid, the genetic blueprint for an organism-that creates a change ... MUTATION CONCEPT A word familiar to all fans of science fiction [1], ... Mutation Biology COPYRIGHT 2002 The Gale Group Inc.. Mutation. Mutations are physical changes in genes and chromosomes . They ... Mutation UXL Encyclopedia of Science COPYRIGHT 2002 The Gale Group, Inc.. Mutation. A mutation is a permanent change in a gene ...
... everything you need for studying or teaching Mutation. ... Immediately download the Mutation summary, chapter-by-chapter ... Same-Sense Mutation A same-sense mutation is form of silent mutation where a change in the base sequence of a gene does not ... Gene Mutation Gene mutation is a sudden change in the DNA making up an individual gene. Gene mutation is a fairly infrequent ... Mutation A mutation is any heritable change in the genome of an organism. For a population, heritable mutations provide the ...
Change in the genetic structure (DNA); it may occur spontaneously or be induced (e.g., by radiation, drugs, or certain mutagenic chemicals ...
5. Mutations affect and are affected by many genes.. The mutation concept is no longer as simple as it once was. Instead of a ... 1. Mutations are random, not directed.. It remains true to say that we know of no way other than random mutation by which new ... 2. Mutations are rare, not common.. It is probably fair to estimate the frequency of a majority of mutations in higher ... 4. The Net Effect of All Mutations is Harmful. Even if the mutations are not harmful enough to cause their carriers to be ...
The production by further mutation [1] of a premutation gene [2] from a mutant gene. This reverse mutation restores the ability ... Strictly, reversion is the correction of a mutation, i.e. ... reverse mutation (reversion) The production by further mutation ... reverse mutation (reversion) The production by further mutation of a premutation gene from a mutant gene. This reverse mutation ... the term is applied also to a mutation at another site that masks or suppresses the effect of the first mutation (in fact such ...
... the pivotal points is called mutation. It enabled the singer to apply the solmization syllables to any series of notes he ... the pivotal points is called mutation. It enabled the singer to apply the solmization syllables to any series of notes he ... Other articles where Mutation is discussed: hexachord: … ... Mutation. music. THIS IS A DIRECTORY PAGE. Britannica does not ...
... (also known as i-umlaut) is the raising and fronting of a root vowel in anticipation of i or y s ... I-Mutation. I-MUTATION (also known as i-umlaut) is the raising and fronting of a root vowel in anticipation of i or y ... 6. I-mutation turns up in an adjective formed from a noun by adding -ish in at least one important case: English (Old English ... I-mutation is caused by the very human habit of laziness: taking the shortest distance between two points. The plural of man in ...
Other family members could still inherit the mutation and should still be tested for the mutation that runs in your family. ... Other family members could still inherit the mutation and should be tested for the mutation that runs in your family. ... You cannot pass the mutation on to your child. If you have LDL cholesterol levels higher than 100 mg/dL, you may be at risk for ... What the test results mean for you and your family if the FH-causing mutation in your family has been found through genetic ...
CHAMP Mutations, United States Excel fileexcel icon. CHBMP F9 Mutation List. The CHBMP F9 Mutation List is an Excel database ... CHAMP F8 Mutation List. The CHAMP F8 mutations that have been reported worldwide. It was compiled from mutations listed ... CHBMP Mutation List Database Excel fileexcel icon. CHBMP F9 Mutations in the United States. As part of the Hemophilia Inhibitor ... CHAMP Mutation List Database Excel fileexcel icon. CHAMP F8 Mutations in the United States. As part of the Hemophilia Inhibitor ...
Mutation. Definition. A mutation is any detectable and heritable change in nucleotide sequence that causes a change in genotype ... Elucidation of the unique mutation spectrum of severe hearing loss in a Vietnamese pediatric population *Jae Joon Han ... microphthalmia plus posterior capsule defect in monozygotic twins caused by a novel GJA8 mutation *Hongfang Zhang ...
Pages in category "Manx mutation templates". The following 2 pages are in this category, out of 2 total. ... Retrieved from "https://en.wiktionary.org/w/index.php?title=Category:Manx_mutation_templates&oldid=28295291" ...
Mutations in which one base is changed are called point mutations-for example, substitution of the nucleotide pair AT by GC, CG ... Mutations arise from changes to the DNA of a gene. These changes can be quite small, affecting only one nucleotide pair, or ... Any mutation that results in a lack of function for a particular gene is called a "null" mutation. Less-severe mutations are ... Mechanisms of mutation. Mutations arise from changes to the DNA of a gene. These changes can be quite small, affecting only one ...
A clinician advocates genetic testing to identify asymptomatic mutation carriers who are at risk for several cancers associated ... has written extensively on genetic testing for mutations related to multiple endocrine neoplasia type 1 - a rare, autosomal- ...
It is the mutation of DNA during cell division. Just one base out of place, and suddenly the gene that made a protein to ...
14 Spirant Mutation. 14.1 The spirant mutation happens after the conjunction/preposition a (and, with -- really the same ...
CpG Mutations.. CpG dinucleotides are known to be mutation hotspots in some cancer types (1, 3-5). Thirty-two percent of the ... We also excluded mutations in intronic splice sites. Analysis of mutation data from ref. 1 for Fig. 3 used version 1 of the ... Mutation frequencies for data from refs. 1 and 3-5 were calculated by dividing the observed number of nonsynonymous mutations ... Transition mutations occur at a significantly higher rate than transversion mutations (6-8). Substitution rates depend on ...
... have a higher level of genetic somatic mutations, compared with other regions where... ... They chose to probe mutations in mice because their generations are renewed every three months, so it could be assumed for the ... "Link Between Asbestos And Genetic Mutation." Medical News Today. MediLexicon, Intl., 15 Jun. 2011. Web.. 20 Sep. 2018. ,https ... not only cause certain cancers but also genetic mutations in DNA structures. It is also known that asbestos is a material that ...
The NAA15 Gene Mutation. June 7, 2018. News, ResearchRablab Gholson Lyon, assistant professor at Cold Spring Harbor Laboratory ... Lyon and his team identified 38 people with a harmful NAA15 mutation, 24 of which had autism features and 23 had an ... Thus, it is critical for autism treatment and intervention to continue to identify patterns in behavior related to mutations in ... in New York found a strong connection between mutations in the NAA15 gene, a protein modifier, and neurodevelopmental delays. ...
Another consequence of this high rate of mutation is that all but the most mild mutator mutations will be lethal. Mutation ... a published mutation frequency f for a particular trait can be converted into a mutation rate μ. A mutation rate μb per base ... few progeny viruses escape mutation. In general, for 1.5c mutations distributed randomly among genomes, the mutation-free ... For mutations studied in riboviruses, T is usually very small; for instance, if the mutations consist exclusively of a single ...
This expense has prevented mutation from becoming widely used in practical situations, but recent... ... Mutation testing is a powerful, but computationally expensive, technique for unit testing software. ... IEEE Computer Society Software Test Mutation Testing Original Program Selective Mutation These keywords were added by machine ... Offutt A.J., Untch R.H. (2001) Mutation 2000: Uniting the Orthogonal. In: Wong W.E. (eds) Mutation Testing for the New Century ...
Neals DNA Mutation Site This site contains: Databases and software for the analysis of mutations at the human hprt, human p53 ... A program for entering mutation data into a relational database Brief descriptions Mutation databases and software Human hprt ...
A mutation which makes itself apparent only under certain conditions, such as low or high temperatures. From the BioTech ... A mutation which makes itself apparent only under certain conditions, such as low or high temperatures. ...
A mutation that causes a mutant gene to revert to its original wild type base sequence. From the BioTech Dictionary at http:// ... A mutation that causes a mutant gene to revert to its original wild type base sequence. From the BioTech Dictionary at http:// ...
In a frameshift mutation, a nucleotide is added or ... mutation: Point Mutations mutation: Point Mutations. Enter your ... Occasionally a mutation can be offset by either another mutation on the same gene or on another gene that suppresses the effect ... For example, the inherited sickle cell disease is the result of a mutation that results in the substitution of the amino acid ... A single gene mutation may have many effects if the enzyme it controls is involved in several metabolic processes. ...
Without genetic mutation, genes would not vary, and natural selection would be powerless to act. But if genetic mutation ... Mutation rates are typically very small and are thought to be swamped by the amount of genetic divergence seen over ... Variations due to mutation and interspecific differences are similar, perhaps as a result of complex genetic interactions. See ... This challenges several models of the role of mutation in evolution. ...
New genes are being isolated almost daily, Fundamental to those studies is the ability to detect mutations. Mutation detection ... New genes are being isolated almost daily, Fundamental to those studies is the ability to detect mutations. Mutation detection ... Mutation Detection: A Practical Approach. R. G. H. Cotton,E. Edkins,S. Forrest. Limited preview - 1998. ... Mutation Detection: A Practical Approach. Richard G. H. Cotton,Edward Edkins,Sue Forrest. Snippet view - 1998. ...
  • Most of these mutations are in two genes, one of which codes for myosin, a protein crucial to muscle contraction. (harvard.edu)
  • This led to the conclusion that genes needed to be read in a specific " reading frame " and a single base insertion or deletion would shift the reading frame ( frameshift mutation ) in such a way that the remaining DNA would code for a different polypeptide than the one intended. (wikipedia.org)
  • Suppressor mutations also occur in genes that code for virus structural proteins. (wikipedia.org)
  • A BRCA mutation is a mutation in either of the BRCA1 and BRCA2 genes , which are tumour suppressor genes. (wikipedia.org)
  • Hundreds of different types of mutations in these genes have been identified, some of which have been determined to be harmful, while others have no proven impact. (wikipedia.org)
  • Harmful mutations in these genes may produce a hereditary breast-ovarian cancer syndrome in affected persons. (wikipedia.org)
  • Women with deleterious mutations in either the BRCA1 or BRCA2 genes have a high risk of developing breast and/or ovarian cancer . (wikipedia.org)
  • Mutation Mutation is an alteration in an organism's genes. (bookrags.com)
  • Gene Mutations and Genetic Change In a strict sense, mutations are changes in genes not caused by genetic recombination. (bookrags.com)
  • However, mutations in a special class of genes called proto- oncogene s can cause uncontrolled division of that cell, resulting in a group of cells that constitutes a cancerous tumour . (britannica.com)
  • Recent large-scale cancer sequencing studies have focused primarily on identifying cancer-associated genes, but as an important byproduct provide "passenger mutation" data that can potentially illuminate the mutational mechanisms at work in cancer cells. (pnas.org)
  • The germline mutation rate at CpGs is much lower within CpG islands (regions enriched in CpGs surrounding or near the transcription start sites of many genes) reflecting, at least in part, the fact that most islands are likely unmethylated in the germline ( 10 ). (pnas.org)
  • Certain genes are responsible for producing enzymes that can repair some mutations. (factmonster.com)
  • While this process is not fully understood, it is believed that if these genes themselves mutate, the result can be a higher mutation rate of all genes in an organism. (factmonster.com)
  • New genes are being isolated almost daily, Fundamental to those studies is the ability to detect mutations. (google.com)
  • Which type of mutation affects more genes a genes mutation or a chromosomal mutation? (answers.com)
  • The mutation causes knew genes and diversity which can spread quickly throughout a population and eventually change the frequency of alleles (causes mutation) Remember the mutation has to be beneficial to the survival of the organism. (answers.com)
  • Further analysis of the mice bearing the mutation clarified that the gene regulates a number of other genes that have previously-established connections to pain signalling. (ucl.ac.uk)
  • With more research to understand exactly how the mutation impacts pain sensitivity, and to see what other genes might be involved, we could identify novel targets for drug development," said co-author Professor Anna Maria Aloisi (University of Siena), who was part of the team that initially identified the Marsili family's distinctive condition. (ucl.ac.uk)
  • In the first part of the study, the mice with a mutation in the LKB1 gene were seen to have more aggressive tumours than the mice with mutations in other genes. (www.nhs.uk)
  • Most newly arisen mutations in functional genes are deleterious, but the fraction may approach zero for spacer DNAs such as introns and intergenic regions. (genetics.org)
  • they identified no mutations in any of the other genes tested. (www.nhs.uk)
  • Kent and his colleagues focused on mutations in two genes already known to be critical for development of this type of pre-leukaemia. (newscientist.com)
  • Maybe that's why I'd continued my comforting trope about my healthy genes while we evaluated my risk in the context of my sister's mutation-a completely new equation. (nursingcenter.com)
  • [1] Although most phenotypic variation is a product of genetic recombination , all new genes are considered to be produced by mutations. (newworldencyclopedia.org)
  • A tulip flower exhibiting a partially yellow petal because of a mutation in its genes. (wikipedia.org)
  • Mutations in genes can either have no effect, alter the product of a gene , or prevent the gene from functioning properly or completely. (wikipedia.org)
  • [8] Due to the damaging effects that mutations can have on genes, organisms have mechanisms such as DNA repair to prevent or correct mutations by reverting the mutated sequence back to its original state. (wikipedia.org)
  • [11] Novel genes are produced by several methods, commonly through the duplication and mutation of an ancestral gene, or by recombining parts of different genes to form new combinations with new functions. (wikipedia.org)
  • [16] [17] Other types of mutation occasionally create new genes from previously noncoding DNA . (wikipedia.org)
  • Researchers took DNA from tumor tissue and analyzed it for mutations in two genes known to drive cancer-causing proteins targeted by Bayer's drug and medicines from Pfizer Inc. (PFE) and Novartis AG (NOVN) , Sutent and Gleevec. (bloomberg.com)
  • Could create genetic mutation that harm the animal but may create ones that make it adaptable into living and reproducing. (answers.com)
  • In the 1990s, virologists in New York learned of a genetic mutation that would become one of the most famous ever discovered. (theatlantic.com)
  • Scientists have identified a genetic mutation responsible for a rare condition called epilepsy and mental retardation limited to females (EFMR), The Times reports. (www.nhs.uk)
  • However, mice with a genetic mutation to the gene Gabrb1 overwhelmingly preferred drinking alcohol over water, choosing to consume almost 85% of their daily fluid as drinks containing alcohol. (ucl.ac.uk)
  • Researchers discovered a genetic mutation, which makes breastfeeding physically harder to achieve. (dailymail.co.uk)
  • They're about three and a half feet tall and their origins are mysterious, but an isolated group of Ecuadorians with a genetic mutation causing dwarfism are making news for another reason: They hardly ever get cancer or diabetes. (discovermagazine.com)
  • An international team of scientists writing in the journal Nature Genetics has helped to identify a single genetic mutation in National Paracycling Champion Tom Staniford that has led to his extremely rare condition. (redorbit.com)
  • Image 2 (below): Researchers identify the single genetic mutation responsible for rare condition in UK Paracycling Champion, Tom Staniford. (redorbit.com)
  • 2) A nonsense mutation is a change of base at one point in the DNA that causes a stop signal where one shouldn't be and halts the creation of a protein in the middle. (mit.edu)
  • 3) A missense mutation is a change of base at a point in the DNA that results in the substitution of a different amino acid than originally intended at some point in the protein. (mit.edu)
  • 4) A neutral mutation is one leading to a substitution of a different amino acid than originally intended, but not to one that alters the function of the protein. (mit.edu)
  • 5) A silent mutation is one that does not lead to a change in the amino acid sequence of a protein. (mit.edu)
  • Therefore, researchers concluded that the second mutation of opposite sign suppresses the original mutation by restoring the reading frame, as long as the portion between the two mutations is not critical for protein function. (wikipedia.org)
  • For example, a mutation which disrupts the complementary interaction between protein molecules may be compensated for by a second mutation elsewhere in the genome that restores or provides a suitable alternative interaction between those molecules. (wikipedia.org)
  • An amber mutant of phage T4 contains a mutation that changes a codon for an amino acid in a protein to the nonsense stop codon TAG (see stop codon and nonsense mutation ). (wikipedia.org)
  • However, it was found that viable phage could sometimes be produced in the host with the weak nonsense suppressor if a second amber mutation in a gene that encodes another structural protein is also present in the phage genome. (wikipedia.org)
  • Amber, Ocher, and Opal Mutations Amber, ocher and opal mutations are specific types of nonsense mutations that result in production of protein chain terminating codons that prematurely stop protein sy. (bookrags.com)
  • Same-Sense Mutation A same-sense mutation is form of silent mutation where a change in the base sequence of a gene does not result in a change in the amino acid sequence of the protein for which the g. (bookrags.com)
  • This reverse mutation restores the ability of the gene to produce a functional protein. (encyclopedia.com)
  • Each mutation has been reviewed and uniquely identified using the Human Genome Variation Society (HGVS) external icon nomenclature for DNA and predicted protein changes, as well as using traditional nomenclature based on the mature processed protein. (cdc.gov)
  • A more severe type of base substitution , called a " nonsense " mutation, results in a stop codon in a position where there was not one before, which causes the premature termination of protein synthesis and, more than likely, a complete loss of function in the finished protein. (britannica.com)
  • Large deletions of many codons will not only remove amino acids from a protein but may also result in a frameshift mutation if the number of nucleotides deleted is not a multiple of three. (britannica.com)
  • Second, some nonsense or frameshift mutations can lead to the complete absence of a protein. (britannica.com)
  • Gholson Lyon, assistant professor at Cold Spring Harbor Laboratory in New York found a strong connection between mutations in the NAA15 gene, a protein modifier, and neurodevelopmental delays. (washington.edu)
  • Researchers examined a mutation called the missense rs4238001 variant, which alters the type of protein made by the gene SCARB1, and thereby the body's cholesterol regulation. (medicalnewstoday.com)
  • In a frameshift mutation, a nucleotide is added or deleted to the sequence and the decoding of the entire gene sequence will be radically altered and the amino acid sequence of the protein produced will also be very different. (factmonster.com)
  • A newly identified mutation in the leptin gene causes early-onset extreme obesity by rendering the protein biologically inactive rather than absent. (medscape.com)
  • The mutation alters a part of the gene's protein sequence that is normally consistent across species as variable as mice and frogs. (ucl.ac.uk)
  • The mutation, a deletion of 25 letters of genetic code from the heart protein gene MYBPC3, is virtually restricted to people from the Indian subcontinent. (redorbit.com)
  • The mutation leads to the formation of an abnormal protein," explained the study leader, Kumarasamy Thangaraj from the Centre for Cellular and Molecular Biology, Hyderabad, India. (redorbit.com)
  • Of course, some protein evolution certainly results from favorable mutations, and to this extent the neutral fraction is overestimated. (genetics.org)
  • In JAK2 , this kind of mutation, called a point mutation, replaces the normal amino acid valine (abbreviated V) with phenylalanine (abbreviated F). This amino acid change results in a JAK2 protein that is constantly "on," leading to uncontrolled blood cell production. (labtestsonline.org)
  • All of the mutations in the PCDH19 gene in women with EFMR were predicted to stop the PCDH19 protein from functioning. (www.nhs.uk)
  • Two of the mutations in the gene were shown to stop the gene from producing protein by prematurely breaking down the chemical messages sent from the gene to the protein-making machinery of the cells. (www.nhs.uk)
  • A missense mutation in the gene coding for the protein hemoglobin substitutes the base thymine for adenine. (reference.com)
  • A silent mutation occurs when a DNA message changes but the message still codes for the same amino acid and produces the correct protein. (reference.com)
  • The Zebrafish Mutation Project (ZMP) aims to create a knockout allele in every protein--coding gene in the zebrafish genome, using a combination of ENU mutagenesis, whole exome enrichment and Illumina sequencing, in addition to a targeted CRISPR/Cas9 approach. (sanger.ac.uk)
  • Light chain amyloidosis, a deadly protein misfolding disease, is caused by multiple mutations in cells that are intended to protect the body. (news-medical.net)
  • Through a combination of crystallography, nuclear magnetic resonance spectroscopy, and bioinformatics, they were able to determine the surface shape of the molecule involved with one mutation and also deduce that it was constantly shifting its position, from 90 degrees to 180 degrees off the normal position of the comparable functional protein. (news-medical.net)
  • In this specific case, the researchers were able to identify that the mutation called the Tyr-to-His substitution in the reconfiguration at position 87 on the protein was the alteration that promoted fibril development. (news-medical.net)
  • Analysis of the protein variant revealed that the mutation was p.Pro507Ser. (hindawi.com)
  • Mutations in a specific protein called ZnT2 can stop mammary glands developing, as as a result stopping mothers producing enough milk to feed a child, it found. (dailymail.co.uk)
  • In 1989, CF became the first disease pinned to a specific gene mutation, without the benefit of knowing the protein first. (discovermagazine.com)
  • Laron syndrome results from a mutation in the gene that codes for growth hormone receptor (GHR), a protein that binds with the human growth hormone and ultimately results in the production of the insulin-like growth factor 1 (IGF1), causing cells to grow and divide. (discovermagazine.com)
  • One study on genetic variations between different species of Drosophila suggests that, if a mutation changes a protein produced by a gene, the result is likely to be harmful, with an estimated 70 percent of amino acid polymorphisms that have damaging effects, and the remainder being either neutral or marginally beneficial. (wikipedia.org)
  • A 2007 study on genetic variations between different species of Drosophila suggested that, if a mutation changes a protein produced by a gene, the result is likely to be harmful, with an estimated 70% of amino acid polymorphisms that have damaging effects, and the remainder being either neutral or marginally beneficial. (wikipedia.org)
  • Researchers showed that mutations caused by either a single base insertion (+) or a single base deletion (-) could be "suppressed" or restored by a second mutation of the opposite sign, as long as the two mutations occurred in the same vicinity of the gene. (wikipedia.org)
  • But now that the UConn study made the connection between the mutation in SCARB1 and heart disease, the researchers want to figure out a way to fix it. (medicalnewstoday.com)
  • Two other mutations causing congenital analgesia are being actively explored by researchers alongside pharmaceutical firms, but have yet to yield any breakthrough drugs. (ucl.ac.uk)
  • The second part of this study found that only 34% of human lung tumours had the mutations in the gene that the researchers were investigating. (www.nhs.uk)
  • The researchers then investigated the effects of the mutations and the interactions between the different genetic mutations and the characteristics of the lung tumours that developed in the mice. (www.nhs.uk)
  • In the second part of the study, the researchers looked at DNA from 144 frozen samples of human lung cancer tumours and looked for the presence of four mutations, including the mutation at LKB1. (www.nhs.uk)
  • In the second part of the study, the researchers found an LKB1 mutation in 34% of the human lung adenocarcinomas and in 19% of the human squamous cell carcinomas. (www.nhs.uk)
  • Knowing that there is an association between the LKB1 mutation and some lung cancers does not mean that researchers would know how to prevent cancer in people with this mutation. (www.nhs.uk)
  • Heart disease is one of the world's leading killers, but now that researchers have identified this common mutation, carried by one in 25 people of Indian origin, we have hope of reducing the burden that the disease causes. (redorbit.com)
  • Researchers have discovered the first definitive proof that a mutation in a single gene can cause Parkinson's disease, the second most common brain degenerative disorder after Alzheimer's disease. (wsj.com)
  • By investigating 7,329,860 somatic mutations from the cancer genomes, the researchers were able to effectively look back in time, calculating which mutations each cell had had before it became a cancer cell. (lanl.gov)
  • NEW YORK, Jan. 31 (UPI) -- A gene mutation could increase the potential of aggressive tumor development in men suffering from prostate cancer, U.S. researchers say. (upi.com)
  • After HIV researchers made CCR5 -Δ32 famous, scientists in other fields got interested in the mutation, too. (theatlantic.com)
  • This led the researchers to identify the gene Gabrb1 which changes alcohol preference so strongly that mice carrying either of two single base-pair point mutations in this gene preferred drinking alcohol (10% ethanol v/v - about the strength of wine), over water. (ucl.ac.uk)
  • The researchers found that the gene mutation caused the receptor to activate spontaneously even when the usual GABA trigger was not present. (ucl.ac.uk)
  • Overall survival in patients with metastatic lung cancer does not correlate with Kirsten rat sarcoma viral oncogene homologue mutation subtypes, US researchers report. (news-medical.net)
  • Researchers at the Center for iPS Cell Research and Application, Kyoto University, show that induced pluripotent stem (iPS) cells can be used to correct genetic mutations that cause Duchenne muscular dystrophy (DMD). (news-medical.net)
  • Researchers have identified additional resistance mechanisms that could be targeted to improve the efficacy of irreversible epidermal growth factor receptor-tyrosine kinase inhibitors in patients with non-small-cell lung cancer harbouring both EGFR and T790M mutations. (news-medical.net)
  • Mayo Clinic researchers have identified one of these mutations and have shown that the molecule's shifting position is as important as its unique shape. (news-medical.net)
  • Researchers say that while this is just one of many possible mutations, it is a beginning towards identifying targets for future drug development in a condition that is otherwise fatal. (news-medical.net)
  • Researchers had access to samples from both early and later stages of the disease, enabling them to see the order in which key mutations appeared in affected blood cells. (newscientist.com)
  • Reuters) - A specific mutation in the new coronavirus can significantly increase its ability to infect cells, according to a study by U.S. researchers. (reuters.com)
  • The researchers say that it is still unknown whether this small mutation affects the severity of symptoms of infected people, or increases mortality. (reuters.com)
  • Researchers unveiled a comprehensive look at the genetic mutations responsible for two cancers Wednesday as part of a broad government-sponsored initiative to enlist the power of genomic information to transform cancer treatment. (foxnews.com)
  • In a study of Bayer AG (BAYN) 's drug Stivarga, researchers analyzed tissue and blood samples from patients with gastrointestinal stromal tumors, or GIST, to find cancer-driving mutations. (bloomberg.com)
  • As cancer treatments increasingly home in on known genetic causes of the disease, researchers need better tools to determine just what mutations each patient has, said George Demetri, director of the Ludwig Center at Dana-Farber Cancer Institute and Harvard Medical School, who led the trial. (bloomberg.com)
  • Bayer jointly promotes Stivarga with Onyx Pharmaceuticals Inc. In the study, researchers took blood samples from patients once their cancer had progressed and analyzed them for mutations, including so- called secondary mutations that cause resistance to those drugs. (bloomberg.com)
  • Newer versions of the technology are being worked on now that would enable researchers to seek out unidentified cancer-causing mutations, which could be helpful for drug development. (bloomberg.com)
  • Another type of point mutation that can lead to drastic loss of function is a frameshift mutation , the addition or deletion of one or more DNA bases. (britannica.com)
  • With Padrón's expertise in structural biology and Seidman's keen knowledge of genetics, the two investigated how HCM-associated mutations change the structural interactions of myosin that occur during cardiac relaxation. (harvard.edu)
  • Intragenic suppression results from suppressor mutations that occur in the same gene as the original mutation. (wikipedia.org)
  • Germinal mutations are those that occur in the egg or sperm cells and therefore can be passed on to the organism's offspring. (encyclopedia.com)
  • Mutations may occur due to exposure to natural mutagens such as ultraviolet (UV) light, to industrial or environmental mutagens such as be. (bookrags.com)
  • For a population, heritable mutations provide the source of genetic variation, without which evolution could not occur: If all. (bookrags.com)
  • Radiation Mutagenesis Mutations are caused by DNA damage and genetic alterations that may occur spontaneously at a very low rate. (bookrags.com)
  • If recessive mutations occur in both members of one gene pair in the same cell, the mutant phenotype will be expressed. (britannica.com)
  • Transition mutations occur at a significantly higher rate than transversion mutations ( 6 - 8 ). (pnas.org)
  • Note that such trends could reflect mutations arising before carcinogenesis that are carried along by subsequent clonal expansion, in addition to mutations that occur within the cancer cells themselves. (pnas.org)
  • Does it arise as a consequence of microevolutionary processes that occur at the species level 1 , such as mutation, selection and the random genomic changes in a population known as genetic drift? (nature.com)
  • Mutations allow new versions of DNA combinations to occur. (answers.com)
  • Which is the single most important type of mutation that eventually allows for evolution via natural selection to occur? (answers.com)
  • IT IS well known that cancers can develop from mutations in DNA - but now we've seen for the first time that a person's fate may depend on the order in which they occur. (newscientist.com)
  • Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses , or can occur deliberately under cellular control during processes such as hypermutation. (newworldencyclopedia.org)
  • Mutations can also occur in nongenic regions . (wikipedia.org)
  • ➋, genomes with two mutations, which may arise in sequential replications (as in the fourth line) or during a single replication (as in the bottom line). (pnas.org)
  • Mutation rates in RNA viruses, whose genomes contain ca. 10 4 bases, are roughly 1 per genome per replication for lytic viruses and roughly 0.1 per genome per replication for retroviruses and a retrotransposon. (genetics.org)
  • Through the course of a lifetime all cells are thought to acquire mutations in their genomes. (lanl.gov)
  • Sebat and his colleagues looked for gene mutations in the genomes of 8,290 people with schizophrenia and 7,431 healthy people. (livescience.com)
  • The team sequenced and compared the entire genomes of the participants and their families, helping them pinpoint the exact mutation responsible for MDP Syndrome. (redorbit.com)
  • Mutations in which one base is changed are called point mutations -for example, substitution of the nucleotide pair AT by GC, CG, or TA. (britannica.com)
  • Point mutations can have one of three effects. (genome.gov)
  • Point mutations are a large category of mutations that describe a change in single nucleotide of DNA, such that that nucleotide is switched for another nucleotide, or that nucleotide is deleted, or a single nucleotide is inserted into the DNA that causes that DNA to be different from the normal or wild type gene sequence. (genome.gov)
  • The cause of the excessive drinking was tracked down to single base-pair point mutations in the gene Gabrb1, which codes for the beta 1 subunit, an important component of the GABAA receptor in the brain. (ucl.ac.uk)
  • [1] Women with harmful mutations in either BRCA1 or BRCA2 have a risk of breast cancer that is about five times the normal risk, and a risk of ovarian cancer that is about ten to thirty times normal. (wikipedia.org)
  • Mutations that allow an organism to survive and reproduce better than other members of its species are always beneficial, though a mutation that may be beneficial in some circumstances can be harmful in others. (encyclopedia.com)
  • The creation model, on the other hand, would predict that, if there are any such things as real mutations, causing 'vertical' changes in complexity and order of the kings, they will be harmful, not beneficial. (angelfire.com)
  • Accordingly, the great majority of mutations, certainly well over 99%, are harmful in some way, as is to be expected of the effects of accidental occurrences. (angelfire.com)
  • Even if the mutations are not harmful enough to cause their carriers to be eliminated completely by natural selection, the over-all effect is to gradually lower the viability of the population. (angelfire.com)
  • The large majority of mutations, however, are harmful or even lethal to the individual in whom they are expressed. (angelfire.com)
  • Lyon and his team identified 38 people with a harmful NAA15 mutation, 24 of which had autism features and 23 had an intellectual disability. (washington.edu)
  • How can such a harmful mutation be so common? (redorbit.com)
  • However, most mutations actually are harmful, such as seen in genetic diseases, leading to speculation that the role of mutations may be overstated by evolutionary biologists and that other factors, perhaps less random, may be of greater importance in the origin of new designs and macroevolutionary changes. (newworldencyclopedia.org)
  • A word familiar to all fans of science fiction , mutation refers to any sudden change in DNA - deoxyribonucleic acid, the genetic blueprint for an organism - that creates a change in an organism's appearance, behavior, or health. (encyclopedia.com)
  • Mutation A mutation is any heritable change in the genome of an organism. (bookrags.com)
  • Spontaneous Mutations and Reversions Mutations and reversions are events that change the expression of traits of an organism. (bookrags.com)
  • A proportion of favorable mutations of one in a thousand does not sound much, but is probably generous, since so many mutations are lethal, preventing the organism living at all, and the great majority of the rest throw the machinery slightly out of gear. (angelfire.com)
  • In most cases, the somatic cell with the mutation will die, an event that is generally of little consequence in a multicellular organism . (britannica.com)
  • A somatic mutation will only affect the organism which already contains that mutation and will not pass that mutation to its offspring. (answers.com)
  • A gametic mutation may not affect the organism which contains the mutation, but that mutation may or will be passed to its offspring, where the mutation might be, or can be expressed. (answers.com)
  • The mutation has to be a beneficial mutation, meaning that it has to help the survival of the organism that got the mutation. (answers.com)
  • a mutation occurring in a somatic cell, resulting in a change in the morphology or some other aspect of one part of an organism (usually a plant). (dictionary.com)
  • It was clear to me then that cancer is an evolutionary process that the organism does not want," he said: After malignant cells arise through mutation, competition among those cells selects for the ones best able to run rampant through the body. (wired.com)
  • In biology , mutation is a sudden change in the base pair sequence of the genetic material of a living organism , whether the genetic material be deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). (newworldencyclopedia.org)
  • In biology , a mutation is the permanent alteration of the nucleotide sequence of the genome of an organism , virus , or extrachromosomal DNA or other genetic elements. (wikipedia.org)
  • In biology, a mutation is an alteration in the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA. (wikipedia.org)
  • Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. (wikipedia.org)
  • First, the base substitution can be a silent mutation where the altered codon corresponds to the same amino acid. (genome.gov)
  • What is a silent mutation? (reference.com)
  • A mutation is any detectable and heritable change in nucleotide sequence that causes a change in genotype and is transmitted to daughter cells and succeeding generations. (nature.com)
  • JAK2 V617F mutation is acquired as opposed to inherited and results in the change of a single DNA nucleotide base pair. (labtestsonline.org)
  • [3] It was found that the reason the second amber mutation could suppress the first one is that the two numerically reduced structural proteins would now be in balance. (wikipedia.org)
  • Because proteins called enzymes control most cell activities, a mutation affecting an enzyme can result in alteration of other cell components. (factmonster.com)
  • They determined that the Stellar mutation, which occurs in one of the proteins that make up the SPT complex, causes an increase in the number of "long" 20-carbon sphingolipids. (cnbc.com)
  • Instead, the mutations send misfolded bundles of proteins through the bloodstream, potentially destroying the heart, kidneys, liver or other organs. (news-medical.net)
  • Immunoglobulin molecules made in cells from the bone marrow are subject to mutations that can cause the proteins to misfold. (news-medical.net)
  • If we can identify women who will have trouble with breast-feeding while they're still pregnant - by identifying mutations in their ZnT2 proteins - then maybe we can help them better prepare before the baby comes. (dailymail.co.uk)
  • It is probably fair to estimate the frequency of a majority of mutations in higher organisms between one in ten thousand and one in a million per gene per generation. (angelfire.com)
  • more loosely, the term is applied also to a mutation at another site that masks or suppresses the effect of the first mutation (in fact such organisms are not non-mutant, but double mutants with the same phenotype ). (encyclopedia.com)
  • A previous analysis of mutation rates in RNA viruses (specifically in riboviruses rather than retroviruses) was constrained by the quality and quantity of available measurements and by the lack of a specific theoretical framework for converting mutation frequencies into mutation rates in this group of organisms. (pnas.org)
  • Rates of spontaneous mutation per genome as measured in the laboratory are remarkably similar within broad groups of organisms but differ strikingly among groups. (genetics.org)
  • In the case of RNA viruses, the mutation rate is higher than in other organisms. (bio.net)
  • In multicellular organisms that reproduce sexually , mutations can be subdivided into germ line mutations , which can be passed on to descendants, and somatic mutations , which cannot be transmitted to descendants in animals. (newworldencyclopedia.org)
  • In most organisms, this means the mutation impacts the base pairs of deoxyribonucleic acid (DNA). (newworldencyclopedia.org)
  • What is missense mutation? (reference.com)
  • A missense mutation occurs when a gene is altered in a way that results in a different amino acid being substituted for the one originally coded. (reference.com)
  • The frequency of these mutations can be increased by using special age. (bookrags.com)
  • The man probably more responsible than any other for the modern view of evolution known as neo-Darwinism, which says evolution proceeds by the accumulation of small mutations preserved by natural selection, is even less confident in the frequency of beneficial mutations. (angelfire.com)
  • We then show that the increased CpG mutation frequency observed in some cancers primarily occurs outside of CpG islands and CpG island shores, thus rejecting the hypothesis that the increase is a byproduct of island or shore methylation followed by deamination. (pnas.org)
  • We also demonstrate that the relative frequency of mutations at dinucleotide "hotspots" can be used as a tool to detect likely technical artifacts in large-scale studies. (pnas.org)
  • This study clearly indicates that there is a link between the higher levels of asbestos in the environment and the frequency of genetic somatic mutations in the mammals," the scientists said. (medicalnewstoday.com)
  • Here, we describe a robust relationship among the mutation frequency f , the easily determined growth parameter c , and the mutation rate μ. (pnas.org)
  • The key attribute of iterative replication is that the mutation frequency f equals the mutation rate μ per copying event: if n complementary strands are copied from a template and if μ is the mutation rate per copying event, then the number of mutations will be n μ, and f = n μ/ n = μ. (pnas.org)
  • Ignoring rare precise back mutations and in the absence of selection, this mutant subpopulation will persist at the frequency f 1 . (pnas.org)
  • Tyrosine kinase inhibitor sensitivity may be predicted by the frequency of a point mutation in the epidermal growth factor receptor gene, suggests a study of Japanese patients with advanced lung adenocarcinoma. (news-medical.net)
  • The existence of strong taxonomic patterns of mutability implies that genomic mutation rates are close to an evolutionary equilibrium whose driving forces we consider here. (genetics.org)
  • As genomic science and potential gene therapies continue to develop, the detection of mutations plays an increasingly central role in diverse areas of biology. (booksamillion.com)
  • A mutation caused by duplication, deletion or inversion comes under the category of chromosomal mutation. (answers.com)
  • Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements . (wikipedia.org)
  • Why BRCA1 and BRCA2 mutations lead preferentially to cancers of the breast and ovary is not known, but lack of BRCA1 function seems to lead to non-functional X-chromosome inactivation . (wikipedia.org)
  • Mutations also can be errors in all or part of a chromosome. (encyclopedia.com)
  • Applies mutation operator to a 'Chromosome', a bitstring, really. (cpan.org)
  • if there is a mutation on one chromosome, the other chromosome compensates for the defect. (www.nhs.uk)
  • Males, who have only one X chromosome, usually cannot compensate and they will be affected by the disease caused by the mutation. (www.nhs.uk)
  • The mutation had previously been found to lie on a part of the X chromosome called Xq22. (www.nhs.uk)
  • Changes in chromosome number may involve even larger mutations, where segments of the DNA within chromosomes break and then rearrange. (wikipedia.org)
  • These myosin mutations simply switch one amino acid for another. (harvard.edu)
  • It turned out that many of the amino acids involved in the molecular interactions of relaxation are the very ones that are altered by HCM mutations. (harvard.edu)
  • For example, enzymes are particularly susceptible to mutations that affect the amino acid sequence at their active site (i.e., the region that allows the enzyme to bind with its specific substrate). (britannica.com)
  • We first examine the overall impact of selection on the mutation spectra by comparing synonymous and nonsynonymous substitution frequencies (mutations per site sequenced) in pancreatic cancer and glioblastoma multiforme ( 4 , 5 ) and by examining the nature of amino acid changes in breast and colorectal cancers ( 1 ). (pnas.org)
  • For example, the inherited sickle cell disease is the result of a mutation that results in the substitution of the amino acid valine for glutamic acid in hemoglobin . (factmonster.com)
  • The abundance of some genetic changes within the gene pool can be reduced by natural selection, while other "more favorable" mutations may accumulate and result in adaptive changes. (wikipedia.org)
  • [3] Natural selection is proposed to increase beneficial mutations and select against and eliminate deleterious mutations. (newworldencyclopedia.org)
  • In microbial genetics , a revertant is a mutant that has reverted to its former genotype or to the original phenotype by means of a suppressor mutation, or else by compensatory mutation somewhere in the gene (second site reversion). (wikipedia.org)
  • reverse mutation ( reversion ) The production by further mutation of a premutation gene from a mutant gene. (encyclopedia.com)
  • A mutation that causes a mutant gene to revert to its original wild type base sequence . (everything2.com)
  • Few investigators of the genetics of RNA viruses have focused specifically on mutation rates , although mutant frequencies are often noted to be high compared with those observed in microbes with DNA chromosomes. (genetics.org)
  • Analysis of mutations in TP53 suggests that diverse tumor types are affected by different mutation processes ( 18 ). (pnas.org)
  • However they exhibited substantially different mutation rates in the different tumor types and surprisingly they also had different rates to each other, even in the same type of tumor. (lanl.gov)
  • [ 33 , 34 ] However, CHEK2 Y390C mutation in BC prevents the activation of p53 and the proliferation of cells along with lack of DNA repair, as well as accumulation of mutations in genome of cells that eventually lead to the proliferation of tumor cells and their metastasis to different parts of the body. (medscape.com)
  • [ 36 ] Despite this, Y390C mutation in breast tumor cells impairs the activation of p53, and the cells thus become resistant to apoptosis. (medscape.com)
  • However, the mutation in CHEK2 domains in breast cancer impairs the cell-cycle control mechanisms, leading to the resistance of breast tumor cells to apoptosis and the metastasis of those cells to other parts of the body. (medscape.com)
  • A simple blood sample turned up cancer-causing mutations more frequently than a tumor biopsy in a study that suggests the approach could help deliver a clearer picture of the disease and better tailor patients' treatments. (bloomberg.com)
  • The problem for the last decade of research is when you take out one tumor and sample one corner of the tumor and then sample another, you may see two different mutations in that same tumor," Demetri said in an interview. (bloomberg.com)
  • On the right, a fairly common mutation in mice causes bands in the coat around the body. (mit.edu)
  • Mice inhabiting a northern town of Israel known for its high concentration of asbestos-contaminated dust, have a higher level of genetic somatic mutations, compared with other regions where asbestos pollution levels are lower. (medicalnewstoday.com)
  • They chose to probe mutations in mice because their generations are renewed every three months, so it could be assumed for the study that dozens of generations of this sample population in Nahariya had already been exposed to the fibers. (medicalnewstoday.com)
  • The results indicated differences between the groups' DNA and that the Nahariya-based mice had higher levels of genetic somatic mutations. (medicalnewstoday.com)
  • They then bred a new line of mice that had the relevant mutation, and those mice were notably insensitive to high temperatures. (ucl.ac.uk)
  • In the first part of the study, mice with particular genetic mutations (including a mutation in a gene called LKB1) were given a virus that causes lung tumours. (www.nhs.uk)
  • Mice with the LKB1 mutation also developed a greater range of tumours than those with the other mutations. (www.nhs.uk)
  • Working at the MRC Mammalian Genetics Unit, a team led by Professor Howard Thomas from Imperial College London introduced subtle mutations into the genetic code at random throughout the genome and tested mice for alcohol preference. (ucl.ac.uk)
  • The group showed that mice carrying this mutation were willing to work to obtain the alcohol-containing drink by pushing a lever and, unlike normal mice, continued to do so even over long periods. (ucl.ac.uk)
  • Their experiments on mice suggest that ZnT2 mutations cause deficiencies in breast milk and may create difficulty for breastfeeding in general. (dailymail.co.uk)
  • Rates of spontaneous mutation are critical to understanding the genetic structure of populations over time and thus to understanding the course of evolution. (pnas.org)
  • High-risk mutations, which disable an important error-free DNA repair process ( homology directed repair ), significantly increase the person's risk of developing breast cancer , ovarian cancer and certain other cancers. (wikipedia.org)
  • The risk of BRCA -related breast cancers for men with the mutation is higher than for other men, but still low. (wikipedia.org)
  • [3] However, BRCA mutations can increase the risk of other cancers, such as colon cancer , pancreatic cancer , and prostate cancer . (wikipedia.org)
  • We observe an A→G vs. T→C mutational asymmetry in some cancers similar to one that has been observed in germline mutations in transcribed regions, suggesting that the mutation process may be influenced by gene expression. (pnas.org)
  • In contrast, TpC dinucleotides are a mutation hotspot in breast cancers ( 16 ), but not in the germline ( 17 ). (pnas.org)
  • Earlier studies of asbestos have already shown that the thin fibers, which penetrate the body by inhalation or through consumption of food contaminated with the material, not only cause certain cancers but also genetic mutations in DNA structures. (medicalnewstoday.com)
  • To evaluate the risks of other cancers in BRCA1 mutation carriers, we conducted a cohort study of 11 847 individuals from 699 families segregating a BRCA1 mutation that were ascertained in 30 centers across Europe and North America. (nih.gov)
  • BRCA1 mutations may confer increased risks of other abdominal cancers in women and increased risks of pancreatic cancer in men and women. (nih.gov)
  • If the effects of mutation order were established for all common cancers, it could have a dramatic impact on treatment, says Kent. (newscientist.com)
  • We hope that our study will stimulate the search in other cancers for whether or not the order of mutation acquisition matters," he says. (newscientist.com)
  • It is quite remarkable that a single mutation in a relatively rare GABA receptor gene can lead to such a profound change in alcohol consumption. (ucl.ac.uk)
  • We had to look at thirty million base pairs in Tom's DNA, and similar numbers in his family members and the other patients, to identify the single mutation. (redorbit.com)
  • However, the majority of mutations actually identified are presumed to be "passenger" mutations that are not advantageous to the cancer cell ( 2 ). (pnas.org)
  • Or third, the base substitution can be a nonsense mutation where the altered codon corresponds to a stop signal. (genome.gov)
  • This test detects activating mutations at codon 600 of the BRAF gene, including the V600E, V600K, and V600R mutations. (nationwidechildrens.org)
  • It detects expected mutations, while is unable to turn up unknown drivers of cancer. (bloomberg.com)
  • There were no mutations in this gene in the males with non-EFMR mental retardation or in control X chromosomes from people without mental retardation or epilepsy, which supported the fact that mutations in PCDH19 specifically cause EFMR. (www.nhs.uk)
  • Since mutation usually affects a single individual in a population, the initial fraction is small and the probability of fixation is thus also small (high probability of loss). (mit.edu)
  • The authors concluded that mutation in the LKB1 gene affects the ability of a cell to suppress the development of a tumour. (www.nhs.uk)
  • The mutation affects a gene that regulates learning and behavior, which makes sense considering these cognitive abilities are often impaired in people with schizophrenia, said study researcher Jonathan Sebat, an assistant professor of psychiatry and cellular and molecular medicine at the University of California, San Diego. (livescience.com)
  • Further studies will be needed to confirm that mutations in this gene are causing possible cases of EFMR in other families and to investigate why the disease affects women and not men. (www.nhs.uk)
  • Finally, a common mutation in humans causes red blood cells to be shaped in a sickle pattern as shown above on the upper left. (mit.edu)
  • A common mutation in a gene that regulates cholesterol levels may raise the risk of heart disease in carriers, according to a new UConn Health study. (medicalnewstoday.com)
  • The rate of spontaneous mutation is a key parameter in modeling the genetic structure and evolution of populations. (pnas.org)
  • Applying this formulation to the available data provides the best estimate to date of the rate of spontaneous mutation in riboviruses. (pnas.org)
  • i] spontaneous mutation ii] induced mutation iii] germinal mutation iv] somatic mutation v] chromosomal mutation vi] gene mutation are the some of the major types of mutation. (answers.com)
  • From one point of view, passenger mutations are an annoying "haystack" complicating the search for causal mutations. (pnas.org)
  • Attempts to detect order in these mutation rates have revealed certain underlying patterns. (genetics.org)
  • There are tests available to detect mutations in JAK2 exon 12 and to identify other non-V617F mutations. (labtestsonline.org)
  • The screen, called BEAMing technology, is sensitive enough to detect even rare mutations circulating in the blood stream in the form of free DNA, genetic material shed from tumors. (bloomberg.com)
  • on the other hand, if a germinal mutation is involved, what was once an abnormality may become so common in certain populations that it emerges as the norm. (encyclopedia.com)
  • A suppressor mutation is a second mutation that alleviates or reverts the phenotypic effects of an already existing mutation in a process defined synthetic rescue . (wikipedia.org)
  • Look up suppressor mutation in Wiktionary, the free dictionary. (wikipedia.org)
  • Over the eons, advantageous mutations, examples of which we look at later, have allowed life to develop and diversify from primitive cells into the multitude of species - including Homo sapiens - that exist on Earth today. (encyclopedia.com)
  • Those structures stymie evolution by denying advantageous mutations any chance to take over a population. (wired.com)
  • Only 5-10% of breast cancer cases in women are attributed to BRCA1 and BRCA2 mutations (with BRCA1 mutations being slightly more common than BRCA2 mutations), but the impact on women with the gene mutation is more profound. (wikipedia.org)
  • [2] The risk of breast and ovarian cancer is higher for women with a high-risk BRCA1 mutation than with a BRCA2 mutation. (wikipedia.org)
  • Methods to diagnose the likelihood of a patient with mutations in BRCA1 and BRCA2 getting cancer were covered by patents owned or controlled by Myriad Genetics . (wikipedia.org)
  • Approximately 50% to 65% of women born with a deleterious mutation in BRCA1 will develop breast cancer by age 70, and 35% to 46% will develop ovarian cancer by age 70. (wikipedia.org)
  • Dr. Robert Burk of New York's Yeshiva University said his study found that men with a BRCA1 or BRCA2 gene mutation were facing a greater risk of developing aggressive tumors, The Canadian Broadcasting Corp. reported Friday. (upi.com)
  • Their familial descent was chosen since the Ashkenazi Jewish population is much more likely to have a BRCA1 and BRCA2 gene mutation. (upi.com)
  • Cancer Incidence in BRCA1 mutation carriers. (nih.gov)
  • Germline BRCA1 mutations confer a substantial lifetime risk of breast and ovarian cancer, but whether cancer at other sites is increased is less clear. (nih.gov)
  • Relative risks (RRs) of each cancer type in BRCA1 carriers relative to risks for the general population were estimated by weighting individuals according to their estimated probability of being a mutation carrier. (nih.gov)
  • In carriers of BRCA1 mutations, the overall increased risk of cancer at sites other than breast and ovary is small and is observed in women but generally not in men. (nih.gov)
  • The basic evolution model would predict, therefore, that mutations must be primarily beneficial, generating a 'vertical' change upward toward higher degrees of order. (angelfire.com)
  • As a matter of fact, the phenomenon of a truly beneficial mutation, one which is known to be a mutation and not merely a latent characteristic already present in the genetic material but lacking previous opportunity for expression, and one which is permanently beneficial in the natural environment, has yet to be documented. (angelfire.com)
  • A central premise of the theory of evolution through natural selection is that when beneficial mutations appear, they should spread throughout a population. (wired.com)
  • because if they continued forever, too many mutations would accumulate in the individual. (scienceblogs.com)
  • The molecular clocks generate mutations at a steady rate, the "ticking" rate of the clock, and accumulate more mutations with age. (lanl.gov)
  • Nonlethal mutations accumulate within the gene pool and increase the amount of genetic variation. (wikipedia.org)
  • Mutation is a phenomenon significant to many aspects of life on Earth and is one of the principal means by which evolutionary change takes place. (encyclopedia.com)
  • Mutations become especially important when an organism's environment is changing - something that has happened often over the course of evolutionary history. (encyclopedia.com)
  • Mutation is a major evolutionary force that results from wide range of factors and that carries a w. (bookrags.com)
  • It is now possible to specify some of the evolutionary forces that shape these diverse mutation rates. (genetics.org)
  • In evolutionary theory , specifically the theory of evolution by natural selection , mutation is considered the main source of new variation in a population. (newworldencyclopedia.org)
  • Mutation is the ultimate source of all genetic variation, providing the raw material on which evolutionary forces such as natural selection can act. (wikipedia.org)
  • Mutation A mutation is a sudden change in DNA (deoxyribonucleic acid), the genetic material of life. (bookrags.com)
  • A mutation on a gene that regulates brain development is associated with a 14-fold increased risk of schizophrenia. (livescience.com)
  • Chromosomal mutation can have lasting impacts on the person who this happens to. (answers.com)
  • A basic principle of genetics is that the likelihood that a particular mutation occurs is independent of its phenotypic consequences. (nih.gov)
  • Up-to-date, user friendly, and comprehensive, the Guide to Mutation Detection is an invaluable resource for students and practitioners working across a wide range of genetics-related disciplines. (booksamillion.com)
  • Human Mutation is a peer-reviewed medical journal of human genetics published by Wiley-Liss on behalf of the Human Genome Variation Society. (wikipedia.org)
  • We first show that selection (negative or positive) has affected only a small fraction of mutations, allowing us to attribute observed trends to underlying mutational processes rather than selection. (pnas.org)
  • Some of the mutational processes generating these mutations do so in bursts and these will often be through external exposures such as sunbathing or tobacco smoking. (lanl.gov)
  • Other mutational processes, however, may be internal to the cell and generate mutations continuously, at a constant rate over decades. (lanl.gov)
  • Y390C mutation occurs in the serine/threonine kinase domain, [ 26 ] which disrupts the kinase function of CHEK2 and prevents the phosphorylation of downstream factors in the signaling pathway. (medscape.com)
  • As part of the Hemophilia Inhibitor Research Study (HIRS), the Division of Blood Disorders at the Centers for Disease Control and Prevention (CDC) tested more than 1400 patients and identified over 250 unique mutations in the factor VIII gene, F8 , to identify the mutation in the gene that caused their hemophilia A. This Excel database lists mutation results for patients tested as part of HIRS. (cdc.gov)
  • Our results suggest that most coding sequence mutations in cancer are neutral with respect to cancer growth. (pnas.org)
  • In a recent survey ( D rake 1993a ), most of the mutation rates that could be calculated were necessarily based on results obtained with very small and thus potentially unrepresentative mutational targets, and contained other experimental and calculational uncertainties. (genetics.org)
  • Elevation of 20-carbon long chain bases due to a mutation in serine palmitoyltransferase small subunit b results in neurodegeneration. (cnbc.com)
  • Disease progression-free survival is similar for patients with non-small-cell lung cancer and epidermal growth factor receptor mutations whether they receive erlotinib or gefitinib, show the results of a South Korean study. (news-medical.net)
  • In Mutation, Cook explores the possible results of genetic engineering, zygote implantation, and surrogate motherhood. (bookrags.com)
  • This error-prone process often results in mutations. (wikipedia.org)
  • They might be the result of a mutation in cells, or the result of a chemical or nuclear reaction. (dezeen.com)
  • Blood samples from people in the study showed that the people with the mutation had greater expression and greater activity of the gene than people without the mutations, the study said. (livescience.com)
  • Earlier and much smaller studies have shown more vulnerability to the flu and West Nile in people with the mutation, but there is no evidence of increased mortality in the 500,000 people of the U.K. Biobank database. (theatlantic.com)
  • In addition to the reading frame, Crick also used suppressor mutations to determine codon size. (wikipedia.org)
  • If adaptive mutations are rare, as seems to be the case, then rates of DNA sequence evolution are driven mainly by mutation and random drift, as K imura ( 1983a ) has argued. (genetics.org)
  • They compared these sequences with the normal gene sequences and looked for mutations (changes in the sequence). (www.nhs.uk)
  • Once they identified mutations within one gene, they then looked at the sequence of this gene in 87 other women with EFMR-like conditions (epilepsy with cognitive impairment), which had not yet been proven to be EFMR. (www.nhs.uk)
  • Information about mutations is delivered to observers as an ordered sequence of MutationRecords, representing an observed sequence of changes that have occurred. (mail-archive.com)
  • All mutations made to all observed nodes in all registrations for a given observer are delivered, in time-ordered sequence, via a single invocation of the MutationCallback's handleEvent method. (mail-archive.com)
  • It will be updated annually with newly published or submitted mutations and corrections. (cdc.gov)
  • Mutation is a newly formed 4 piece heavy metal band from the Twin Cities. (first-avenue.com)
  • As a result, half of the people with BRCA gene mutations are male, who would then pass the mutation on to 50% of their offspring, male or female. (wikipedia.org)
  • You cannot pass the mutation on to your child. (cdc.gov)
  • This was a genetic study which aimed to identify the mutation that causes the disease: epilepsy and mental retardation limited to females (EFMR). (www.nhs.uk)
  • Here, we describe a simple relation between ribovirus mutation frequencies and mutation rates, apply it to the best (albeit far from satisfactory) available data, and observe a central value for the mutation rate per genome per replication of μ g ≈ 0.76. (pnas.org)
  • These uncertainties included lack of information about what proportion of lytic virus replication is linear (repeated copying of the same template) and what is binary (as in most DNA replication), as well as lack of information about the relative contributions of transcription and reverse transcription to retroviral mutation rates. (genetics.org)
  • Genetic suppression therefore restores the phenotype seen prior to the original background mutation. (wikipedia.org)
  • The second mutation is not on the same gene as the original mutation. (wikipedia.org)
  • it must not be forgotten that mutation is the ultimate source of all genetic variation found in natural populations and the only new material available for natural selection to work on. (angelfire.com)
  • But mutations are found to be of a random nature, so far as their utility is concerned. (angelfire.com)
  • Data from the Israeli Ministry of Health indicate a rise in the number of cancer patients from exposure to asbestos in the Western Galilee region of northern Israel, and therefore the scientists set out to examine whether genetic mutations are found in the mouse population living in its northern town of Nahariya. (medicalnewstoday.com)
  • They found that changes in the wing-vein patterns evolve very slowly, given the amount of variation that is produced by mutations. (nature.com)
  • In this case, the mutation in the gene was found in only 34% of the human tumours that were analysed. (www.nhs.uk)
  • These two clock-like processes, termed Signature 1 and Signature 5, showed a correlation between the number of mutations found in each cancer sample and the age of the patient when the cancer was diagnosed. (lanl.gov)
  • A study with roundworms in the journal Cell Metabolism found that a diet rich in sugar offset a mutation that ordinarily doubled the worms' life spans. (scientificamerican.com)
  • In previous work, Cynthia Kenyon of the University of California, San Francisco, found that a mutation to a gene called daf-2 changed insulin signaling and doubled the lifespan of the worms. (scientificamerican.com)
  • They found several mutations that seemed to be associated with schizophrenia. (livescience.com)
  • They found that disease was noticeable 10 years earlier in people with JAK2 -first mutations, because they were overproducing blood cells at high levels from the outset. (newscientist.com)
  • The study of 100,000 women by the Institute of Cancer Research found women with the mutations had a much greater risk of breast cancer. (telegraph.co.uk)
  • A month after the accident, scientists who study the pale grass blue butterfly collected 144 near the plant, and found that they had begun to show mutations like dented eyes and deformed wings . (discovermagazine.com)
  • They found secondary mutations in 48 percent of blood samples, versus 12 percent of tissue samples. (bloomberg.com)
  • Does not this fact show that mutations are really assaults on the organism's central being, its basic capacity to be a living thing? (angelfire.com)
  • This mutation is not always expressed on the outside but can affect that organism's offspring. (answers.com)
  • Mutations involve a change in the base pair of an organism's genetic material. (newworldencyclopedia.org)
  • The accumulation of mutations during a single round of infection. (pnas.org)
  • The authors had measured this variation in mutation-accumulation experiments, generating large numbers of sublines from inbred fly lines, breeding these sublines for many generations and then measuring mutational variation from the wing-vein differences between the sublines 4 . (nature.com)
  • This test looks for mutations in JAK2 that are associated with bone marrow disorders caused by the production of too many blood cells. (labtestsonline.org)
  • The bone marrow disorders caused by JAK2 mutations are known as myeloproliferative neoplasms (MPNs) in which the bone marrow produces too many white blood cells, red blood cells, and/or platelets. (labtestsonline.org)
  • The primary JAK2 test is JAK2 V617F, named for a mutation at a specific location in the JAK2 gene. (labtestsonline.org)
  • Other mutations in the JAK2 gene are also associated with MPNs. (labtestsonline.org)
  • Of these, the team identified 12 samples in which TET2 had unequivocally mutated first, and another 12 in which the JAK2 mutation came first. (newscientist.com)
  • In cell culture, these mutants were easier to kill with targeted JAK2 inhibitor drugs than cells from those with TET2 -first mutations, but Kent's team has yet to test that this is also true inside the human body. (newscientist.com)
  • By contrast, the disease was more hidden in those who developed TET2 mutations first and was more likely to develop into full-blown leukaemia, but people in this group were less likely to suffer or die from blood clots than those who developed JAK2 mutations first. (newscientist.com)