Molecular and General Genetics MGG

, Volume 175, Issue 1, pp 57–65

Characterization of the mutator mutation mut5-1

  • D. P. Morrison
  • P. J. Hastings

DOI: 10.1007/BF00267856

Cite this article as:
Morrison, D.P. & Hastings, P.J. Molec. Gen. Genet. (1979) 175: 57. doi:10.1007/BF00267856


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.

Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • D. P. Morrison
    • 1
  • P. J. Hastings
    • 1
  1. 1.Department of GeneticsUniversity of AlbertaEdmontonCanada
  2. 2.Biology BranchAtomic Energy of Canada Limited, Chalk River Nuclear LaboratoriesChalk RiverCanada
  3. 3.Biology and Health Physics DivisionAtomic Energy of Canada Limited, Chalk River Nuclear LaboratoriesChalk RiverCanada

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