REPLICATION AND SEGREGATION OF BASAL BODIES

纤毛和鞭毛，以及它们生长的基体，高度 在真核细胞的进化过程中一直是保守的。从单细胞 原生生物在哺乳动物系统中分化成各种类型的细胞。 基本小体在结构上类似于中心粒，起着 一组复杂的细胞骨架结构的组织部位，包括 微管、小根和各种横纹纤维。这些细胞骨架 元素似乎参与了基体区的适当分离 细胞周期，在决定或维持细胞极性时，在 其他细胞器的定位，以及在锚定纤毛和 细胞内有鞭毛。单细胞双鞭毛藻 衣藻长期以来一直被用作研究人类免疫缺陷病毒的模式遗传系统 参与鞭毛功能的基因。突变体的遗传学研究进展 具有异常鞭毛数量的研究表明，这种表型是由 基体的复制、成熟和分离的缺陷 在细胞周期中。插入法的最新进展 衣藻的诱变极大地促进了基因的克隆 通过突变来鉴定的。这些新方法将被用来克隆基因 参与基础身体功能的。具体目标是：1)使用 插入突变技术用于识别与基底相关的基因 通过分离突变体进行复制、分离和定位 鞭毛数目异常；2)克隆突变鉴定的基因 并通过DNA测序对其进行鉴定；3)检测其功能 通过详细的细胞学分析每个基因的突变表型； 4)检测基因的时空定位 产品使用免疫细胞化学。很可能许多人 该项目中确定的与基础身体功能有关的蛋白质将 在哺乳动物细胞中有同源物，如纤毛上皮细胞、精子 细胞和感觉细胞。这个项目的结果将提供更好的 了解这些细胞中的细胞骨架。

Cilia and flagella, and the basal bodies from which they grow, are highly conserved throughout the evolution of eukaryotic cells. from unicellular protists to various types of differentiated cells in mammalian systems. Basal bodies, which are analogous to centrioles in structure, serve as the organizing site for a complex set of cytoskeletal structures including microtubule rootlets and various striated fibers. These cytoskeletal elements appear to be involved in segregating basal bodies properly during the cell cycle, in determining or maintaining cellular polarity, in positioning of other cellular organelles, and in anchoring cilia and flagella in the cell. The unicellular biflagellate green alga Chlamydomonas has long been used as a model genetic system to study the genes involved in flagellar function. Previous genetic studies of mutants with abnormal flagellar number have shown that this phenotype results from defects in the replication, maturation, and segregation of basal bodies during the cell cycle. The recent development of methods for insertional mutagenesis in Chlamydomonas has greatly facilitated the cloning of genes identified by mutation. These new methods will be used to clone genes involved in basal body function. The specific aims are: 1) to use insertional mutagenesis to identify genes involved in basal body replication, segregation, and localization by isolating mutants with abnormal flagellar number; 2) to clone the genes identified by mutation and to characterize them by DNA sequencing; 3) to examine the function of each gene through detailed cytological analysis of the mutant phenotype; and 4) to examine the spatial and temporal localization of the gene products using immunocytochemistry. It is likely that many of the proteins involved in basal body function identified in this project will have homologs in mammalian cells such as ciliated epithelial cells, sperm cells, and sensory cells. Results from this project will provide a better understanding of the cytoskeleton in these cells.