Molecular and General Genetics MGG

, Volume 180, Issue 1, pp 99–105 | Cite as

The trans action of HMRa in mating type interconversion

  • Jasper Rine
  • Ira Herskowitz


HML and HMR are the sites of cryptic mating type genes in the yeast Saccharomyces cerevisiae. In the presence of the HO gene, the information from HML or HMR (an a or α cassette) is transferred to the mating type locus (MAT). HML, HMR, and MAT are located on chromosome III, yet are widely separeted. Similarly, in other yeasts, at least some of the genes involved in mating type interconversion are linked to the mating type locus. We demonstrate here that a cassette donor (HMR) and the cassette target (MAT) need not be physically linked for successful mating type interconversion. In particular, we show that HMRa on one chromosome can donate an a cassette to the mating type locus on a homologous chromosome III.


Saccharomyces Cerevisiae Saccharomyces Type Gene Type Locus Mating Type 
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Copyright information

© Springer-Verlag 1980

Authors and Affiliations

  • Jasper Rine
    • 1
    • 2
  • Ira Herskowitz
    • 1
    • 2
  1. 1.Department of BiologyUniversity of OregonEugeneUSA
  2. 2.Institute of Molecular BiologyUniversity of OregonEugeneUSA

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