GENETIC CONTROL OF SISTER CHROMATID EXCHANGE IN YEAST

酵母姐妹染色单体交换的遗传控制

• 批准号: 3941472
• 负责人: M A RESNICK
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3941472
• 关键词: DNA repair; Saccharomyces; fungal genetics; gene complementation; gene mutation; genetic recombination; genetic regulation; molecular cloning; molecular genetics; mutant; radiation genetics

The mechanism of sister chromatid recombination is poorly understood at the genetic and molecular level. Since it may be important in repair, mutagenesis and gene amplification, we have initiated studies to characterize the process and investigate the genetic control in the yeast Saccharomyces cerevisiae. Sister chromatid recombination is measured by recombination between two fragments of the HIS3 gene which share a 300 base pair region of homology. They are arranged in such a way that recombination will generate a complete gene. We have shown that several of the genes involved in DNA repair are required for the levels observed in wild type cells. Mutations in genes that enhance or depress homologous chromosome recombination have similar function son the sister chromatid recombination process. DNA damaging agents can considerably enhance the process although the cells are resistant to x-ray induced exchange. Mutants have been isolated which can either lead to enhanced levels (esr) or depressed (dsr) levels of exchange. Three mutants (esr1, esr2, esr3) have been characterized extensively. Each of these mutants behaves like a single Mendelian locus. esr1 and esr2 have elevated levels of mitotic gene conversion. Experiments are underway to clone the esr1, esr2, and esr3 genes by complementation.

姐妹染色单体重组的机制很差 在基因和分子水平上理解。 因为它可能是 在修复、诱变和基因扩增中， 启动了研究，以表征该过程并调查 在酿酒酵母中的遗传控制。 妹妹 染色单体重组是通过 HIS3基因的两个片段共享300个碱基对 同源区域。 它们的排列方式 重组将产生完整的基因。 我们已经表明 参与DNA修复的几个基因是 在野生型细胞中观察到的水平。 的基因突变 增强或抑制同源染色体重组， 在姐妹染色单体重组过程中具有类似的功能。 DNA破坏剂可以大大增强这一过程 尽管细胞对X射线诱导的交换有抗性。 突变体已被分离出来，它们要么会导致增强 汇率水平（ESR）或汇率下降（DSR）。 三种突变体 (esr1 ESR 2、ESR 3）已经被广泛地表征。 中的每 这些突变体的行为就像一个单一的孟德尔基因座。 esr1和 ESR2具有升高水平的有丝分裂基因转化。 克隆esr1、esr2和esr3基因的实验正在进行中。 通过互补。