Synaptonemal Complexes and Meiotic Chromosome Metabolism in Yeast

提出的实验解决了在酵母减数分裂期间形成的突触复合体的结构和功能。该复合物中存在的蛋白质将被分离并表征。针对蛋白质的抗体将被提高，然后使用标准免疫细胞学技术来研究复合物的结构。编码蛋白质的基因也将被分离出来。在相关实验中，Kleckner博士将分离和表征rad50基因及其产物，然后确定产物在细胞内的位置。rad50基因的调控，特别是在减数分裂期间也将被检查。减数分裂细胞分裂或减数分裂是几乎所有真核生物生命周期中共同的事件。在减数分裂过程中，同源染色体配对并重组，然后分离成子核。迄今为止，对真核生物重组及其调控的生化机制所知甚少。在显微镜下可以观察到带有接触点或突触的成对染色体。这种突触复合体的出现似乎与重组有关。一些酵母菌突变体，特别是那些受rad50基因影响的突变体，显示出较低的重组频率。rad50基因及其产物和突触复合体蛋白组分的分离和表征将为了解真核生物重组的分子事件奠定坚实的基础。

The proposed experimentation addresses the structure and function of the synaptonemal complexes that form during meiosis in yeast. The proteins present in the complex will be isolated and characterized. Antibody directed against the proteins will be raised and then used to investigate the structure of the complexes using standard immunocytological techniques. The genes encoding the proteins will also be isolated. In related experiments, Dr. Kleckner will isolate and characterize both the rad50 gene and its product, and then determine the intracellular location of the product. Regulation of the rad50 gene, especially during meiosis will also be examined. Meiotic cell division, or meiosis, is an event common to the life cycles of virtually all eukaryotic organisms. During meiosis, homologous chromosomes pair and recombine, then segregate to the daughter nuclei. As yet, remarkably little is understood about the biochemical mechanism of eukaryotic recombination or its regulation. Paired chromosomes with sites of contact, or synapses have been observed in the microscope. The occurrence of such synaptonemal complexes appears to correlate with recombination. Some yeast mutants, in particular those affected in the rad50 gene, display lowered frequencies of recombination. The proposed isolation and characterization of the rad50 gene, its product and the protein components of the synaptonemal complex will lay a solid foundation for understanding the molecular events of eukaryotic recombination.