Rad52-independent mitotic gene conversion in Saccharomyces cerevisiae frequently results in chromosomal loss.
Rad52-independent mitotic gene conversion in Saccharomyces cerevisiae frequently results in chromosomal loss.
复制标题
酿酒酵母中不依赖于 Rad52 的有丝分裂基因转换经常导致染色体丢失。
作者：
J. Haber;M. Hearn
我们在Rad+和rad52两个酿酒酵母菌株中检测了His4等位基因之间自发的、染色体间有丝分裂重组事件。在Rad+菌株中，74%的His+原营养体是在没有侧翼标记交换的情况下进行基因转换的。在RAD52-1突变纯合的二倍体中，His+原营养体的形成频率不到野生型的5%，80%以上的基因转换事件伴随着侧翼标记的交换。大多数rad52基因内重组事件是通过基因转换伴随侧翼标记交换而发生的，而不是通过his4A和his4C等位基因之间的简单互换而发生的。对回收的重组产品的种类也有深远的影响。最显著的影响是RAD52独立的有丝分裂重组经常导致参与基因转换事件的两条染色体中的一条丢失。
We have examined spontaneous, interchromosomal mitotic recombination events between his4 alleles in both Rad+ and rad52 strains of Saccharomyces cerevisiae. In Rad+ strains, 74% of the His+ prototrophs resulted from gene conversion events without exchange of flanking markers. In diploids homozygous for the rad52-1 mutation, the frequency of His+ prototroph formation was less than 5% of the wild-type value, and more than 80% of the gene conversion events were accompanied by an exchange of flanking markers. Most of the rad52 intragenic recombination events arose by gene conversion accompanied by an exchange of flanking markers and not by a simple reciprocal exchange between the his4A and his4C alleles. There were also profound effects on the kinds of recombinant products that were recovered. The most striking effect was that RAD52-independent mitotic recombination frequently results in the loss of one of the two chromosomes participating in the gene conversion event.