Involvement of Double-strand Chromosomal Breaks for Mating-type Switching in Saccharomyces cerevisiae
This extract was created in the absence of an abstract.
Excerpt
In the yeast Saccharomyces cerevisiae, a- or α-mating type is determined by the alternate alleles of the mating-type locus, MATa or MATα, respectively. These alleles differ by a DNA substitution lying in the center of the locus: MATa contains the 642-bp Ya sequence, whereas MATα contains the nonhomologous 747-bp Yα sequence (Astell et al. 1981; see Fig. 1). These alleles can be interchanged inefficiently at a frequency of about 1 × 10−6 in heterothallic (ho) cells (Hawthorne 1963a; Rabin 1970). In contrast, the MATa and MATα alleles switch as often as every generation in homothallic strains, i.e., strains containing the HO gene (Hawthorne 1963b; Hicks and Herskowitz 1976; Strathern and Herskowitz 1979; Klar et al. 1982). The information required for interchanging MATa and MATa is transposed from the storage loci, HML and HMR, which contain unexpressed MAT information (Oshima and Takano 1971; Hicks et al. 1977, 1979; Klar and Fogel...
