mutation rate

(redirected from Rate of mutation)

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 ?
It was concluded that the increased rate of mutation resulted from ingesting contaminated food coupled with mutations of the genetic material passed from the parent to the next generation.
Reich's team identified 2,058 mutational changes, yielding a rate of mutation that suggests human and chimpanzee ancestral populations diverged between 3.
What was the rate of mutation development among all infected patients in the current study?
That rate of mutation is rapid but similar to rates seen in the deadly antibiotic-resistant Staphylococcus aureus bacterium called MRSA.
MLPA analysis picked up an additional 9 mutations not picked up by mPCR, increasing the pickup percentage by 7 per cent and increases its rate of mutation detection by 19 per cent of all no deletion samples.
VDA moves the virus to the point of collapse by increasing its naturally high rate of mutation.
Due to the high rate of mutation in the HIV virus, viral diversity is extensive.
Alex Ford, who led the study, said the rate of mutation was extremely worrying.
HIV mocks immune system memory, which isn't flexible enough to account for HIV's constant rate of mutation.
He also shows that if there aren't enough interconnections relative to the number of parts and to the rate of mutation, then even if a good solution is found, random mutations will tend to carry the system away from the optimum faster than selection can drag it back (the "error catastrophe").
Unlike other therapeutics that are designed to inhibit a specific viral protein or enzyme, drugs based on VDA are designed to selectively disrupt the HIV genome by further increasing its naturally high rate of mutation to lethal levels with the goal of eventually causing the collapse of the viral population.
Newer research estimated that the rate of mutation in modern human families based on DNA from the nucleus that involves another way of getting at the common ancestor timing.