mutation rate


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mu·ta·tion rate

the probability (or proportion) of progeny genes with a particular component of the genome not present in either biologic parent; usually expressed as the number of mutants per generation occurring at one gene or locus.

mutation rate

(1) The rate of a new mutation in a particular gene, either per gamete or per generation.
(2) The number of mutations per cell division, determined by Luria-Dulbruck fluctuation analysis.

mu·ta·tion rate

(myū-tā'shŭn rāt)
The probability (or proportion) of progeny genes with a particular component of the genome not present in either biologic parent; usually expressed as the number of mutants per generation occurring at one gene or locus.

mutation rate

The number of instances of a particular gene mutation occurring in a population in one generation.

mutation rate

the number of mutations per gene in a fixed time. In sexual organisms this is often measured as the number of mutations per gamete. Rates vary considerably between genes and between organisms, but a typical rate is 1 mutation per locus per 100 000 gametes. In bacteria it can be measured as the average number of mutations per cell per division.

mutation

1. a nucleotide change, including base substitutions, insertions or deletions in DNA, or RNA in the case of some viruses, that gives rise to the mutant phenotype.
2. an animal exhibiting such change. Called also a sport.

back mutation
see reverse mutation (below).
base substitution mutation
may be a transition in which a purine-pyrimidine pair is substituted by the other purine-pyrimidine pair, or transversion in which a purine-pyrimidine pair is replaced by one of the two pyrimidine pairs.
chain termination mutation
one in which the new base sequence introduces a stop codon and thereby prematurely terminates synthesis of the polypeptide; the three mutations are also called amber (UAG), ochre (UAA) and opal (UGA).
deletion mutation
one produced by loss of nucleotides from a DNA sequence.
frame shift mutation
occur as a result of either the insertion of a new base pair or the deletion of a base pair or a block of base pairs from the DNA base sequence; these, unless they occur in 3 or multiples of 3, are most serious in that the message to the right of the frame shift is garbled.
leaky mutation
one in which the amino acid substitution only partially disrupts the function of the protein; in bacteria this is usually manifested by reduced growth rate.
mis-sense mutation
one causing an amino acid substitution in the protein.
nonsense mutation
one in which a stop codon is substituted for a codon that specifies an amino acid.
operator constitutive mutation
one or more base changes in the operator region (originally defined for the lactose operon) which stop the repressor protein from tightly binding to sequence such that it is less effective in preventing RNA polymerase from inhibiting transcription.
point mutation
a single changed base pair in the DNA of an organism which may be a base substitution, base insertion or base deletion.
mutation rate
the frequency of mutations in the population over time.
repressor-constitutive mutation
in regulation of gene expression, a mutation in the repressor protein that decreases the binding affinity of the repressor protein for the operator which leaves the gene permanently turned on.
reverse mutation
one in which the wild-type phenotype is restored; such organisms are called revertants. Called also back mutation, reversion mutation.
second-site mutation
see suppressor mutation.
silent mutation
one in which there is a base change but because of the redundancy of the genetic code the same amino acid is coded, or one in which there is an amino acid substitution in the protein which has no detectable effect on the phenotype.
somatic mutation
a change in the DNA sequence that occurs in somatic cells, i.e. not gametes. The mechanism underlying the generation of diversity of antigen recognition by immunoglobulins and T cell receptor molecules. The fundamental cause of cancer, in which the mutation occurs spontaneously or is induced by carcinogens, such as sunlight, chemicals or viruses.
suppressor mutation
a particular type of reversion mutation in which a mutation at a second site restores the original phenotype; most simply a mutation produced by a base deletion may be restored to wild type by a proximate but independent base substitution. Called also second-site mutation.
temperature-sensitive (ts) mutation
one in which there is an altered protein that is active at one temperature, typically 86°F (30°C) and inactive at a higher temperature, usually 104 to 108°F (40 to 42°C), e.g. ts mutant virus and bacteria.
transdominant mutation
occur in genes producing diffusible products, in contrast to cis-dominant mutation in which mutations occur in regulatory sequences that are recognized by other proteins.
transition mutation
one in which the base change does not change the pyrimidine-purine orientation. See also base substitution mutation (above).
transposition mutation
one produced by the insertion of a transposable genetic element.
transversion mutation
one in which the purine-pyrimidine orientation is changed to pyrimidine-purine or vice versa. See also base substitution mutation (above).
References in periodicals archive ?
Therefore, in countries with high MEFV mutation rates such as Turkey, MEFV mutation screening should be included in routine tests.
Geneticists in general have struggled to pinpoint mutation rates, says evolutionary geneticist Laurent Frantz of the University of Oxford.
If rifampin induces a stress response, the situation may be analogous to the high mutation rates seen after quinolone exposure (8).
After the objective function and constraints are set and the selection strategy is selected, the population size and the crossover and mutation rates should be set.
If the random number is smaller than mutation rate, then the random number is mutated.
The two parameters that affect the GA performance are population size and mutation rate.
The experiment was conducted as follows: the mutation rate (percentage of population to be mutated with each generation) and immigration rate (percentage of population to be filled by immigration with each generation) were set at zero and thirty percent, respectively and the selection probability was weighted.
The persistence of infection results from a number of unique biological properties of HIV, such as its extreme genetic variability with short generation time and high mutation rate, the phenomenon of transcriptional latency, and the incompletely understood mechanism of CD4 cell depletion.
Short tandem repeat (STR) loci on the human Y chromosome have been especially useful in that their relatively low mutation rate of approximately 0.
Additionally, localized mtDNA heteroplasmy and diversity patterns suggest that one of the most severely contaminated sites in Sumgayit is acting as a source of new mutations resulting from an increased mutation rate.