GENETIC ANALYSIS OF MEIOTIC CHROMOSOME SEGREGATION

减数分裂细胞周期使二倍体生物产生单倍体 配子通过完成一轮DNA复制， 连续几轮的染色体分离。 所以，信徒们 在减数分裂中遗传信息的传递对于 有性生殖生物的繁殖。 A的错误分离 减数分裂期间的单个染色体具有严重的后果，导致 有缺陷或不能生存的后代。 探索潜在的分子 减数分裂染色体分离的机制是必不可少的， 了解染色体如何精确分离以及这个过程 可能会受到干扰。 酵母中减数分裂的顺序， 酿酒酵母，基本上类似于类似的事件 在高等真核生物中;因此，酵母是一个很好的模型 减数分裂染色体分离的研究系统。 遗传分析 酵母减数分裂提供了丰富的信息， 染色体联会和遗传重组介导分离， 第一次减数分裂 然而，很少有基因被证明 在同源染色体所必需的其他过程中起作用 析取 本申请提出使用遗传方法来 鉴定和表征基因，所述基因具有确保同源 第一次减数分裂时染色体分离。 几次减数分裂- 已经分离出了致命的重组能力强的突变体。 的 这些突变体的表型，命名为mes（减数分裂分离） 突变体，表明它们携带的基因突变的功能， 介导染色体分离而不影响重组。 的mes 突变体将进一步表征基因，以确定在什么 逐步染色体分离受到干扰。 野生型基因将 进行克隆和测序 将进行细胞学研究， 将MES基因产物定位于特定的减数分裂结构。 此外，相互作用的基因产物将使用遗传学方法鉴定。 和生物化学方法。 MES功能分析及交互 基因产物将提供染色体如何分离的信息 在减数分裂的细胞周期中具有保真度。

The meiotic cell cycle enables diploid organisms to generate haploid gametes by completing a single round of DNA replication followed by two successive rounds of chromosome segregation. Therefore, the faithful transmission of genetic information at meiosis is essential for the propagation of sexually reproductive organisms. Missegregation of a single chromosome during meiosis has severe consequences, resulting in defective or inviable progeny. Probing the underlying molecular mechanisms of meiotic chromosome segregation is essential to understanding how chromosomes disjoin with fidelity and how this process can be perturbed. The sequence of meiotic events in the yeast, Sacchromyces cerevisiae, is fundamentally similar to the analogous events in higher eukaryotes; therefore, yeast serves as an excellent model system for the study of meiotic chromosome segregation. Genetic analysis of meiosis in yeast has provided a wealth of information concerning how chromosome synapsis and genetic recombination mediate disjunction at the first meiotic division. However, very few genes have been shown to function in other processes essential for homologous chromosome disjunction. This application proposes to use a genetic approach to identify and characterize genes which function to insure homologous chromosome segregation at the first meiotic division. Several meiotic- lethal, recombination-proficient mutants have been isolated. The phenotypes of these mutants, designated mes (meiotic segregation) mutants, suggest that they carry mutations in genes which function to mediate chromosome disjunction without affecting recombination. The mes mutants will be further characterized genetically to determine at what step chromosome segregation has been perturbed. The wild-type genes will be cloned and sequenced. Cytological studies will be performed to localize the MES gene products to specific meiotic structures. Additionally, interacting gene products will be identified using genetic and biochemical approaches. Analysis of function of MES and interacting gene products will provide information about how chromosomes segregate with fidelity during the meiotic cell cycle.