EVOLUTIONARY GENETICS OF DNA REPAIR AND RECOMBINATION

我们的长期目标是确定DNA修复在 重组的进化 通过研究 重组到基因修复，我们希望能推进 理解我们的想法是两个相关的问题。 第一、 是生命系统如何进化以科普 会导致基因损伤，从而导致癌症。 二是 重组的进化功能的问题。 的 拟议的工作将在枯草芽孢杆菌中测试 假设自然遗传转化进化是因为 在DNA修复中的作用 为了验证这一假设，我们建议（1）继续研究 转化和未转化细胞的存活率，（2） 测试染色体重组位点是否是随机的， 与DNA损伤位点一致，（3）确定 主要B的水平。重组蛋白 DNA损伤后的感受态和非感受态亚群 感受态细胞培养，（4）分离感受态细胞的实验 从非感受态细胞中分离细胞，并测量它们的相对 频率和存活率， （5）研究植物的自发性损伤 细胞间介导的转化而不是受体间的转化 细胞和纯化的供体DNA，作为确定 自然条件下的转化机制，以及（6） 选择实验，以提高转化率， 选择DNA损伤剂治疗的幸存者。

Our long term objective is to determine the role of DNA repair in the evolution of recombination. By studying the relationship of recombination to genetic repair, we hope to advance the understanding of what we think are two related problems. First, is the problem of how living systems have evolved in cope with agents with cause genetic damage and, hence, cancer. Second, is the problem of the evolutionary function of recombination. The proposed work will test in the eubacterium Bacillus subtilis the hypothesis that natural genetic transformation evolved because of its role in DNA repair. To test this hypothesis we propose (1) to continue our studies of the survivorship of transformed and untransformed cells, (2) to test whether chromosomal sites of recombination are random or coincident with respect to sites of DNA damage, (3) to determine the levels of the major B. subtilis recombination protein in competent and non-competent subpopulations following DNA damage to a competent cell culture, (4) experiments to isolate competent cells from noncompetent cells and to measure their relative frequencies and survivorship in the presence of varying amounts and kinds of damaging agents, (5) studying spontaneous transformation mediated between cells instead f between recipient cells and purified donor DNA, as a step towards determining the mechanisms of transformation under natural conditions, and (6) selection experiments to increase the rate of transformation by selecting survivors of treatment with DNA damaging agents.