Characterization of the mutator mutation mut5-1

✍ Scribed by Morrison, D. P. ;Hastings, P. J.

• Publisher: Springer
• Year: 1979
• Tongue: English
• Weight: 670 KB
• Volume: 175
• Category: Article
• ISSN: 0026-8925
• DOI: 10.1007/bf00267856

✦ Synopsis

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 on UV-mutability at lower doses was apparent. Diploids homozygous for the mutation are deficient in UV-induced recombination between the alleles his1-1 and hist1-315, mutation being sufficient to account for all the UV-induced histidine prototrophs. Complementation and mapping studies indicate that mut5-1 is allelic to rad51-1, 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.