Genetics of Telomerase in C. elegans

描述（由申请人提供）：端粒酶和端粒长度与人类癌症和衰老有关。一种遗传学方法已被用于鉴定酵母端粒酶活性所需的四种蛋白质，但这些蛋白质中只有一种在高等真核生物中有任何明确的同源物。秀丽隐杆线虫是一种多细胞真核生物，其中端粒酶可以使用无偏正向遗传方法进行研究。到目前为止，已经确定了一种端粒酶活性所需的秀丽隐杆线虫基因mrt-2，而mrt-2是一种DNA损伤检查点蛋白。本建议的具体目的是：1。结果表明，mrt-3突变体对秀丽隐杆线虫的端粒酶催化亚基有缺陷。2. 以高分辨率绘制另一种秀丽隐杆线虫端粒酶突变体mrt-1，克隆mrt-1，并确定其功能。3. 进行大规模的基因筛选，试图确定端粒酶活性所需的大部分或全部秀丽隐杆线虫基因。绘制这些突变体的位置，并测试其位置接近的突变体之间的互补。其中一些基因将以高分辨率绘制并克隆。这些基因的可能功能是体内端粒酶活性所必需的，将通过遗传学、表型和生化研究的结合来评估。这些实验利用秀丽隐杆线虫遗传学的力量来研究高等真核生物的端粒是如何复制的，应该补充目前在其他生物中使用的生化和反向遗传方法。

DESCRIPTION (provided by applicant): Telomerase and telomere length has been implicated in the human conditions of cancer and ageing. A genetic approach has been used to identify four proteins required for telomerase activity in yeast, but only one of these proteins has any clear homologs in higher eukaryotes. C. elegans is a multicellular eukaryote in which telomerase can be studied using an unbiased forward genetic approach. Thus far, one C. elegans gene that is required for telomerase activity, mrt-2, has been identified, and MRT-2 is a DNA damage checkpoint protein. The specific aims of this proposal are: 1. To show that the mrt-3 mutant is defective for the C. elegans catalytic subunit of telomerase. 2. To map another C. elegans telomerase mutant, mrt-1, at high resolution, to clone mrt-1, and to determine the function of mrt-1. 3. To conduct a large-scale genetic screen in an attempt to identify most or all C. elegans genes that are required for telomerase activity. To map the positions of these mutants, and to test for complementation between mutants whose map positions are close together. Some of these genes will then be mapped at high resolution and cloned. Possible functions of these genes that are required for telomerase activity in vivo will be assessed using a combination of genetic, phenotypic and biochemical studies. These experiments, which use the power of C. elegans genetics to study how telomeres of higher eukaryotes are replicated, should complement biochemical and reverse genetic approaches that are currently being used in other organisms.