GENETIC CONTROL OF SISTER CHROMATID EXCHANGE IN YEAST

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两个染色单体之间的重组来测量的。 HIS3基因的片段，其共享300个碱基对的区域， 同源性 它们的排列方式使得重组 生成一个完整的基因 我们已经证明了一些基因 参与DNA修复所需的水平，在野生 类型细胞。 基因突变增强或抑制同源 染色体重组过程 DNA损伤剂可以 虽然细胞对细菌的生长有抵抗力， X射线诱导的交换。 为了更准确地确定 自发姐妹染色单体重组的水平， 制定了大大降低背景水平的程序。 这样可以更准确地确定微小的增加。

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 proces. DNA damaging agents can considerably enhance the process although the cells are resistant to x-ray induced exchange. In order to determine more accurately the levels of spontaneous sister chromatid recombination, we have developed procedures for greatly reducing the background levels. This is allowing small increases to be determined more accurately.