...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Homothallic mating type switching generates lethal chromosome breaks in rad52 strains of Saccharomyces cerevisiae.
【24h】

Homothallic mating type switching generates lethal chromosome breaks in rad52 strains of Saccharomyces cerevisiae.

机译：同源交配类型转换在酿酒酵母的rad52菌株中产生致命的染色体断裂。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In homothallic cells of Saccharomyces cerevisiae, a or alpha mating type information at the mating type locus (MAT) is replaced by the transposition of the opposite mating type allele from HML alpha or HMRa. The rad52-1 mutation, which reduces mitotic and abolishes meiotic recombination, also affects homothallic switching (Malone and Esposito, Proc. Natl. Acad. Sci. U.S.A. 77:503-507, 1980). We have found that both HO rad52 MATa and HO rad52 MAT alpha cells die. This lethality is suppressed by mutations that substantially reduce but do not eliminate homothallic conversions. These mutations map at or near the MAT locus (MAT alpha inc, MATa-inc, MATa stk1) or are unlinked to MAT (HO-1 and swi1). These results suggest that the switching event itself is involved in the lethality. With the exception of swi1, HO rad52 strains carrying one of the above mutations cannot convert mating type at all. MAT alpha rad52 HO swi1 strains apparently can switch MAT alpha to MATa. However, when we analyzed these a maters, we found that few, if any, of them were bona fide MATa cells. These a-like cells were instead either deleted for part of chromosome III distal to and including MAT or had lost the entire third chromosome. Approximately 30% of the time, an a-like cell could be repaired to a normal MATa genotype if the cell was mated to a RAD52 MAT alpha-inc strain. The effects of rad52 were also studied in mata/MAT alpha-inc rad52/rad52 ho/HO diploids. When this diploid attempted to switch mata to MATa, an unstable broken chromosome was generated in nearly every cell. These studies suggest that homothallic switching involves the formation of a double-stranded deoxyribonucleic acid break or a structure which is labile in rad52 cells and results in a broken chromosome. We propose that the production of a double-stranded deoxyribonucleic acid break is the lethal event in rad52 HO cells.
机译：在酿酒酵母的同型细胞中，交配型基因座（MAT）上的α或α交配型信息被来自HMLα或HMRa的相反交配型等位基因的换位所代替。减少有丝分裂并消除减数分裂重组的rad52-1突变也影响同型切换（Malone和Esposito，Proc.Natl.Acad.Sci.U.S.A.77：503-507，1980）。我们发现HO rad52 MATa和HO rad52 MAT alpha细胞都死亡。这种致死性被突变所抑制，该突变可大大减少但不能消除同型转化。这些突变定位在MAT基因座或其附近（MAT alpha inc，MATa-inc，MATa stk1）或与MAT不相关（HO-1和swi1）。这些结果表明，开关事件本身与杀伤力有关。除swi1外，携带上述突变之一的HO rad52菌株根本无法转换交配类型。 MAT alpha rad52 HO swi1菌株显然可以将MAT alpha切换为MATa。但是，当我们分析这些物质时，我们发现几乎没有（如果有的话）真正的MATa细胞。相反，这些a样细胞要么缺失了MAT远侧（包括MAT）的部分III号染色体，要么丢失了整个第三条染色体。大约30％的时间，如果将a样细胞与RAD52 MAT alpha-inc菌株配对，则可以将其修复为正常的MATa基因型。在mata / MAT alpha-inc rad52 / rad52 ho / HO二倍体中也研究了rad52的作用。当该二倍体试图将mata转换为MATa时，几乎在每个细胞中都会产生不稳定的断裂染色体。这些研究表明，同型转换涉及形成双链脱氧核糖核酸断裂或在rad52细胞中不稳定并导致断裂的染色体的结构。我们建议双链脱氧核糖核酸断裂的产生是rad52 HO细胞中的致死事件。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号