What are mutator strains?

Strains were considered mutators when they exhibited frequencies of mutations conferring resistance to rifampin (100 μg/ml) that were 10-fold higher than the median value of mutagenesis (5.04 × 10−9) observed for all studied strains (n = 603) (10-fold mutators).

What is the role of mutator gene?

‘Mutator’ genes increase the mutation rate throughout an organism’s genome by disrupting DNA repair functions.

What is a mutator allele?

Classic evolutionary theory predicts that in asexual populations, mutator alleles, which cause high mutation rates, can fix due to linkage with beneficial mutations. This phenomenon has been demonstrated experimentally and may explain the frequency of mutators found in bacterial pathogens.

What is a mutator phenotype?

The concept of a mutator phenotype implies that a large number of mutations are produced randomly throughout the genome of cancer cells; only a few of which result in clonal proliferation. This heterogeneity of mutated genes militates against any possibility of reverting cancer cells to wild-type normal cells.

What is error prone PCR?

Error-prone PCR (EP-PCR) is the method of choice for introducing random mutations into a defined segment of DNA that is too long to be chemically synthesized as a degenerate sequence. The average number of mutations per DNA fragment can be controlled as a function of the number of EP-PCR doublings performed.

What is the MSH2 gene?

The MSH2 gene provides instructions for making a protein that plays an essential role in repairing DNA. This protein helps fix errors that are made when DNA is copied (DNA replication) in preparation for cell division.

Can mutator genes reduce the mutation rate of the entire genome?

On the opposite, when well adapted, mutators have been shown to evolve to lower mutation rate. This prevents deleterious mutations from reversing the gained fitness [12].

What do proto oncogenes normally do?

Introduction to Proto-oncogenes Often, proto-oncogenes encode proteins that function to stimulate cell division, inhibit cell differentiation, and halt cell death. All of these processes are important for normal human development and for the maintenance of tissues and organs.

What causes Kataegis?

A subfamily of the APOBEC (apolipo-protein B mRNA editing enzyme, catalytic polypeptide-like) cytidine deaminases has been implicated as a source of kataegis mutations in part because aberrant expression in yeast generates a similar C > T substitution mutational signature (Roberts et al., 2013; Taylor et al., 2013).

What is a mutator in biology?

Any gene that produces an increase in spontaneous mutation rates. Their action may be limited to certain alleles or to certain mutational pathways. From: mutator gene in Oxford Dictionary of Biochemistry and Molecular Biology »

What are degenerate primers?

Definition of degenerate primers A degenerate primer is defined as: “A mix of oligonucleotide sequences in which some positions contain a number of possible bases, giving a population of primers with similar sequences that cover all possible nucleotide combinations for a given protein sequence” (Iserte 2013).

What is gene shuffling?

Gene shuffling refers to the creation of different combinations of alleles (forms of genes) during meiosis. Gene shuffling happens in many organisms, but for simplicity, we’ll talk about this process in humans. Two different processes contribute to gene shuffling: independent assortment and crossing over.