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.
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机译：在由> a / > a / > a /α形成孢子而产生的交配型基因座的二倍体中，研究了同型酿酒酵母的交配型相互转化。和> a / > a /α/α四倍体菌株。已经通过包括直接观察细胞α因子敏感性变化的技术来分析配合型开关。跟随交配类型转换的另一种方法利用了以下观察：> a /α细胞表现出极性出芽，而> a / > a 和α/α细胞表现出中间的这些研究表明：（1）赋予同型生命周期（HO）的等位基因比赋予异型生命周期（ho）的等位基因占优势。 （2）HO基因的作用受交配型基因座的控制-在> a / > a 和α/α细胞中有活性，而在> a 中没有作用强> /α细胞。 （3）HO（或HO控制的）基因产物可以独立地作用于位于同一核中不同染色体上的两个交配型等位基因。 （4）在成对的电池中观察到配对类型的开关，每个电池都有相同的变化。
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