FUNCTION OF THE C ELEGANS GENE LIN5 IN MITOSIS

线虫基因 LIN5 在有丝分裂中的功能

• 批准号: 6386963
• 负责人: SANDER VAN DEN HEUVEL
• 金额: $ 30.29万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6386963
• 关键词: Caenorhabditis elegans; cell cycle; cell growth regulation; chromosome movement; cytogenetics; developmental genetics; gene duplication; gene expression; genetic regulation; microtubule associated protein; mitotic spindle apparatus; molecular genetics; phenotype; protein structure function; yeast two hybrid system

During every cell division, the genome needs to be duplicated accurately and a complete set of chromosomes segregated faithfully to each of the daughter cells. Errors in chromosome segregation can have dramatic consequences, as loss or duplication of chromosomes can lead to cell death, result in birth defects or contribute to cancer. How can accurate segregation of chromosomes be accomplished? How can it fail? To answer these questions we need to understand the molecular basis of the mitotic machinery: what are the components used and how do they act to accomplish centrosome duplication, spindle assembly, chromosome movement, sister chromatid separation and a correct timing of all the steps involved? We use Caenorhabditis elegans as a model system to identify genes involved in chromosome segregation in animal cells. To initiate these studies we have focused on the C. elegans gene lin-5. In lin-5 null mutants, cells enter mitosis but chromosomes do not become aligned at the metaphase plate and anaphase is not initiated. Despite these defects, cells exit from mitosis without delay and initiate subsequent rounds of centrosome duplication and DNA replication followed by abortive mitoses. We have cloned the lin-5 gene and found that it is predicted to encode a novel protein. Importantly, the LIN-5 protein localizes to the centrosomes during mitosis. This proposal details our experiments aimed at further understanding the function of lin-5 in vivo. i) we will obtain a precise characterization of the lin-5 mutant phenotype at the cellular level and determine its relationship to the functions of other genes with roles in mitosis (Specific aim 1). ii) We will use genetic approaches to define genes that act in the same mitotic process as lin-5 and characterize those that are the most interesting at a molecular level. As candidates, we have recently isolated an extensive number of mutants that enhance or suppress a temperature-sensitive lin-5 allele (Specific Aims 2 and 3). These studies aim to take advantage of C. elegans as an animal model in which genetics can be used to study cell-cycle regulation during development. Our goals are 1) to determine the function of the lin-5 gene, 2) to identify novel components of the mitotic machinery and 3) to understand how they work together with known components to regulate chromosome segregation.

在每个细胞分裂期间，都需要准确地重复基因组 一组完整的染色体忠实地隔离到每个染色体 子细胞。 染色体隔离的错误可能会产生巨大的 后果，染色体的损失或重复会导致细胞 死亡，导致先天缺陷或导致癌症。 怎么可能 染色体的准确隔离是可以完成的吗？ 怎么会失败？ 要回答这些问题，我们需要了解 有丝分裂机械：使用了什么组件以及它们如何作用 完成中心体重复，主轴组件，染色体 动作，姐妹染色单体分离和所有的正确时机 涉及步骤？ 我们使用秀丽隐杆线虫作为模型系统来识别基因 参与动物细胞中的染色体分离。 启动这些 我们的研究集中在秀丽隐杆线虫基因Lin-5上。 在lin-5 null中 突变体，细胞进入有丝分裂，但染色体在 未启动中期板和后期。 尽管如此 缺陷，细胞不延迟退出有丝分裂，然后启动随后 集中复制和DNA复制的回合。 堕胎有丝线。 我们已经克隆了lin-5基因，发现它是 预测编码一种新型蛋白质。 重要的是，LIN-5蛋白 在有丝分裂过程中定位于中心体。 该建议详细介绍了我们的实验旨在进一步了解 Lin-5体内的功能。 i）我们将获得精确的特征 LIN-5突变体表型在细胞水平上，并确定其 与其他基因在有丝分裂中作用的功能的关系 （特定目标1）。 ii）我们将使用遗传方法定义基因 该作用在与lin-5相同的有丝分裂过程中起作用，并表征 在分子水平上最有趣的是。 作为候选人，我们 最近已经隔离了大量增强或 抑制对温度敏感的LIN-5等位基因（特定目标2和3）。 这些研究旨在利用秀丽隐杆线虫作为动物模型 哪些遗传学可用于研究细胞周期调节 发展。 我们的目标是1）确定LIN-5的功能 基因，2）确定有丝分裂机械的新成分和3） 了解它们如何与已知组件一起调节 染色体分离。