Klapholz S, Esposito R E
Genetics. 1980 Nov;96(3):567-88. doi: 10.1093/genetics/96.3.567.
ATCC4117 is a strain of S. cerevisiae that undergoes a single nuclear division during sporulation to produce asci containing two diploid ascopores (Grewal and Miller 1972). All clones derived from these spores are sporulation-capable and, like the parental strain, form two-spored asci. In this paper, we describe the genetic analysis of ATCC4117. In tetraploid hybrids of vegetative cells of the ATCC4117 diploid and a/a or alpha/alpha diploids, the production of two-spored asci is recessive. From these tetraploids, we have isolated two recessive alleles, designated spo12-1 and spo13-1, each of which alone results in the production of asci with two diploid or near-diploid spores. These alleles are unlinked and segregate as single nuclear genes. spo12-1 is approximately 22 cM from its centromere; spo13-1 has been localized to within 1 cM of arg4 on chromosome VIII. This analysis also revealed that ATCC4117 carries a diploidization gene allelic to or closely linked to HO, modifiers that reduce the number of haploid spores per ascus and alleles affecting the total level of sporulation.
ATCC4117是酿酒酵母的一个菌株，在孢子形成过程中经历一次核分裂，产生含有两个二倍体子囊孢子的子囊（Grewal和Miller，1972年）。从这些孢子衍生的所有克隆都具有孢子形成能力，并且与亲本菌株一样，形成双孢子子囊。在本文中，我们描述了ATCC4117的遗传分析。在ATCC4117二倍体与a/a或α/α二倍体的营养细胞的四倍体杂种中，双孢子子囊的产生是隐性的。从这些四倍体中，我们分离出两个隐性等位基因，分别命名为spo12-1和spo13-1，每个等位基因单独作用都会导致产生含有两个二倍体或近二倍体孢子的子囊。这些等位基因不连锁，作为单细胞核基因分离。spo12-1距离其着丝粒约22厘摩；spo13-1已定位在第八条染色体上arg4基因附近1厘摩范围内。该分析还表明，ATCC4117携带一个与HO等位或紧密连锁的二倍体化基因、减少每个子囊中单倍体孢子数量的修饰基因以及影响孢子形成总水平的等位基因。
