Roman H, Ruzinski M M
Department of Genetics, University of Washington, Seattle 98195.
Genetics. 1990 Jan;124(1):7-25. doi: 10.1093/genetics/124.1.7.
In red-white sectored colonies of Saccharomyces cerevisiae, derived from mitotic cells grown to stationary phase and irradiated with a light dose of x-rays, all of the segregational products of gene conversion and crossing over can be ascertained. Approximately 80% of convertants are induced in G1, the remaining 20% in G2. Crossing over, in the amount of 20%, is found among G1 convertants but most of the crossovers are delayed until G2. About 20% of all sectored colonies had more than one genotype in one or the other sector, thus confirming the hypothesis that conversion also occurs in G2. The principal primary event in G2 conversion is a single DNA heteroduplex. It is suggested that the close contact that this implies carries over to G2 when crossing over and a second round of conversion occurs.
在酿酒酵母的红白扇形菌落中，这些菌落源自生长至稳定期并接受低剂量X射线照射的有丝分裂细胞，基因转换和交叉互换的所有分离产物都可以确定。大约80%的转化体在G1期被诱导产生，其余20%在G2期产生。在G1期转化体中发现有20%的交叉互换情况，但大多数交叉互换会延迟到G2期。所有扇形菌落中约20%在一个或另一个扇形区域具有不止一种基因型，从而证实了G2期也会发生转换的假设。G2期转换的主要初级事件是单个DNA异源双链体。有人提出，这意味着的紧密接触在发生交叉互换和第二轮转换时会延续到G2期。
