Nishida Y, Ono BI. An experimental system for the study of mutations in theHMR locus ofSaccharomyces cerevisiae: the insertion of Ty intoHMRa vs. the conversion ofHMRa toHMRα.
Yeast 2007;
24:723-30. [PMID:
17566140 DOI:
10.1002/yea.1507]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A cross between a sir4-11 strain (sir4-11 HMLalpha MATalpha HMRa, non-mating type) and an a-mating strain (SIR(+) HMLalpha MATa HMRa) of Saccharomyces cerevisiae forms diploid clones at a frequency of 5 x 10(-6), but the obtained diploid clones often (>70%) have altered forms of the HMRa-containing restriction fragment, designated @ HMRa'. We previously found that some HMRa's are associated with the conversion of HMRa to HMRalpha. In this report, we present evidence that another @ HMRa' associates with the insertion of Ty into Ya of HMR. We also found that the sir4-11 strain increased mating frequency by UV irradiation to a level of 9 x 10(-4), and that generation of HMRa' was completely prevented by disruption of RAD52 of the sir4-11 strain. Hence, we conclude that the mutations that cause generation of HMRa' occur in the sir4-11 strain prior to mating. Due to these mutations, the sir4-11 strain converts to alpha-mating type and readily mates with the a-mating strain. We discuss the usefulness of the sir4-11 strain for the study of mutations in the HMR locus of S. cerevisiae.
Collapse