Characterization of the mutator mutation mut5-1
- Cite this article as:
- Morrison, D.P. & Hastings, P.J. Molec. Gen. Genet. (1979) 175: 57. doi:10.1007/BF00267856
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The mutator mutation mut5-1 has been characterized with respect to a range of parameters which have been used to describe DNA repair mutants of yeast. No marked effect of the mutation of UV-mutability at lower doses was apparent. Diploids homozygous for the mutation are deficient in UV-induced recombination between the alleles his1-1 and his1-315, mutation being sufficient to account for all the UV-induced histidine prototrophs. Complementation and mapping studies indicate that mut5-1 is allelic to rad5-1, supporting the conclusion of Hastings et al. (1976) that a mutator may increase spontaneous mutation by modifying repair parameters.
Both mut5-1 homozygous and heterozygous diploids give rise to spontaneous or UV-induced segregants which appear to be the products of nondisjunction events.
The levels of parameiotic recombination (see Sherman and Roman, 1963; Esposito and Esposito, 1974), sporulation and spore viability observed in mut5-1/mut5-1 diploids indicate that the function encoded by RAD51 is required at 2 times during meiosis. An essential role of the function encoded by RAD51 in mitotic and meiotic recombination is indicated.