ANALYSIS OF NEMATODE SEX DETERMINATION

线虫性别决定分析

• 批准号: 3278515
• 负责人: BARBARA J MEYER
• 金额: $ 15.54万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-09-01 至 1990-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3278515
• 关键词: Caenorhabditis elegans; DNA; Drosophilidae; autoradiography; autosome; developmental genetics; endonuclease; fluorescence microscopy; gene complementation; gene dosage; gene expression; genetic regulation; genetic transcription; lethal genes; male; meiosis; messenger RNA; molecular cloning; nondisjunction; nucleic acid hybridization; nucleic acid sequence; sex behavior; sex chromosomes; sex determination

How an organism determines which of two alternative pathways of sexual differentiation to follow is a fundamental problem in development. In C. elegans, a free-living soil nematode, the ratio of X chromosomes to sets of autosomes determines whether the organism develops into a self-fertilizing hermaphrodite (2A:2X) or a male (2A:1X). In addition, a set of autosomal genes responsive to the chromosome balance has been identified as essential for either hermaphrodite development or male development. 1. One of our aims is to determine how C. elegans assesses the ratio of X chromosomes to autosomes and how this measurement affects the expression of sex-determining genes and dosage-compensating genes downstream in the pathway. One approach is a genetical one, isolating male and hermaphrodite lethal mutations and suppressors of genes known to be involved in dosage compensation. A second approach is to perform a descriptive analysis at the cellular level, of intersexual animals, induced either by mutation or by altering X dosage. This description will provide a broader framework in which to think about the consequences of altering the correct assessment of the X:A ratio. Because sexual differentiation is determined by the chromosomal composition, it is often necessary to impose a further mechanism to insure that expression of genes on sex chromosomes is kept equal in the different sexes. 2. another aim is to gain an understanding of the mechanism of dosage compensation. Our approach is to analyze genetically and biochemically loci known to affect the expression of X-linked genes and to identify new loci involved in this process. The biochemical analysis involves assaying X-linked gene expression in animals with mutations suspected to alter dosage compensation in order to determine if, in fact, they do. In addition, the analysis involves the molecular cloning of loci involved in dosage compensation.

有机体如何决定两种性行为途径中的哪一种 差异化是发展的根本问题。 在C. 线虫，一种自由生活的土壤线虫，X 染色体与染色体组的比例 常染色体决定生物体是否发育成自体受精 雌雄同体 (2A:2X) 或雄性 (2A:1X)。 此外，还有一组常染色体 对染色体平衡敏感的基因已被认为是必需的 用于雌雄同体发育或雄性发育。 1. 我们的目标之一是确定线虫如何评估 X 的比率 染色体到常染色体以及这种测量如何影响 下游的性别决定基因和剂量补偿基因 途径。 一种方法是基因方法，将男性和雌雄同体分开 已知与剂量有关的基因的致命突变和抑制因子 赔偿。 第二种方法是在以下位置执行描述性分析： 两性动物的细胞水平，由突变或诱导 通过改变X剂量。 该描述将提供更广泛的框架 考虑改变正确评估的后果 X:A 比率。 因为性别分化是由染色体决定的 组成，通常需要施加进一步的机制来确保 性染色体上的基因表达在不同的个体中保持相同 性别。 2.另一个目的是了解剂量机制 赔偿。 我们的方法是进行遗传和生化分析 已知影响 X 连锁基因表达并识别新基因的基因座 位点参与了这个过程。 生化分析涉及测定 具有疑似改变的突变的动物中的 X 连锁基因表达 剂量补偿以确定它们是否确实如此。 在 此外，该分析还涉及相关基因座的分子克隆 剂量补偿。