MEIOTIC INTERACTIONS OF THE RECA HOMOLOGUE DMCL

减数分裂过程中需要同源重组以提高精确度 同源染色体在第一次减数分裂时的分离。 已经确定了减数分裂所需的几种蛋白质 酵母中的重组，但这些重组的具体作用 重组中的蛋白质在很大程度上是未知的。的长期目标 这项工作是为了确定减数分裂的分子机制 重组和减数分裂细胞确保 重组是在经历分裂之前完成的。这项研究的重点是 在减数分裂重组所必需的一个减数分裂蛋白Dmc1上。 Dmc1与大肠杆菌RecA蛋白的同源性表明Dmc1在 在重组中起着关键作用。重组需要RecA，并且 大肠杆菌中DNA损伤的修复。纯化的RecA促进中枢 重组中的反应：两个人之间形成同源关节 DNA分子。Dmc1蛋白将被提纯并鉴定为 确定它与RecA共享哪些活动。形成了一种 重组产物还需要大量的酶活性 与RecA显示的内容相同。所需的部分或全部蛋白质 减数分裂重组可能形成多蛋白复合体。有现有的 减数分裂过程中形成大复合体的细胞学证据 重组。此外，两种相关的重组蛋白 到Dmc1，已被证明与其他重组蛋白结合。 将使用荧光显微镜、免疫分析和遗传选择 鉴定重组过程中与Dmc1形成复合体的蛋白质。 时间进程和突变分析将被用来表征 重组络合物组装的途径。Dmc1还在 对减数分裂细胞周期的控制。缺乏Dmc1停滞的突变细胞 在减数分裂中。缺氧性细胞周期停滞的机制 Dmc1的遗传特征将通过分离基因 不能逮捕的压迫者。这些实验将会产生结果 与出生缺陷和癌症的病因学有关，还可能提示 改善癌症治疗的方法。

Homologous recombination is required during meiosis to promote accurate segregation of homologous chromosomes at the first meiotic division. Several proteins have been identified that are required for MEIOTIC RECOMBINATION in the yeast Saccharomyces, but the specific role of these proteins in recombination is largely unknown. The long term goals of this work are to determine the molecular mechanism of meiotic recombination and the way in which meiotic cells ensure that recombination is complete before undergoing division. This study focuses on one meiotic protein, Dmc1, that is required for meiotic recombination. Thy homology of Dmc1 to the E. coli RecA protein suggests Dmc1 plays a pivotal role in recombination. RecA is required for recombination and REPAIR OF DNA DAMAGE in E. coli. Purified RecA promotes the central reaction in recombination: the formation of homologous joints between two DNA molecules. Dmc1 protein will be purified and characterized to determine what activities it shares with RecA. The formation of recombination products requires numerous enzymatic activities in addition to those displayed by RecA. Some or all of the proteins required for meiotic recombination may form a multiprotein complex. There is existing cytological evidence that large complexes form during meiotic recombination. In addition, two recombination proteins that are related to Dmc1, have been shown to bind other recombination proteins. Fluorescence microscopy, immunoassay, and genetic selection will be used to identify proteins that form complexes with Dmc1 during recombination. Time-course and mutational analyses will be used to characterize the pathway of recombination complex assembly. Dmc1 also plays a role in the control of the meiotic CELL CYCLE. Mutants cells that lack Dmc1 arrest in meiosis. The mechanisms that causes cell cycle arrest in the absence of Dmc1 will be characterized genetically by isolation of genetic suppressor that fail to arrest. These experiments will yield results relevant to the etiology of birth defects and cancer and may also suggest ways to improve cancer therapy.