Interconversion of Yeast Mating Types III. Action of the Homothallism (HO) Gene in Cells Homozygous for the Mating Type Locus

AUTOR(ES)

Hicks, James B.

RESUMO

Mating type interconversion in homothallic Saccharomyces cerevisiae has been studied in diploids homozygous for the mating type locus produced by sporulation of a/a/a/α and a/a/α/α tetraploid strains. Mating type switches have been analyzed by techniques including direct observation of cells for changes in α-factor sensitivity. Another method of following mating type switching exploits the observation that a/α cells exhibit polar budding and a/a and α/α cells exhibit medial budding.—These studies indicate the following: (1) The allele conferring the homothallic life cycle (HO) is dominant to the allele conferring the heterothallic life cycle (ho). (2) The action of the HO gene is controlled by the mating type locus—active in a/a and α/α cells but not in a/α cells. (3) The HO (or HO-controlled) gene product can act independently on two mating type alleles located on separate chromosomes in the same nucleus. (4) A switch in mating type is observed in pairs of cells, each of which has the same change.

Documentos Relacionados

• Interconversion of Yeast Mating Types I. Direct Observations of the Action of the Homothallism (HO) Gene
• Regulation of yeast mating-type interconversion: feedback control of HO gene expression by the mating-type locus.
• The RAD52 gene is required for homothallic interconversion of mating types and spontaneous mitotic recombination in yeast.
• Healing of mat mutations and control of mating type interconversion by the mating type locus in Saccharomyces cerevisiae
• Identification of a protein that binds to the Ho endonuclease recognition sequence at the yeast mating type locus.