ANALYSIS OF NEMATODE SEX DETERMINATION

生物体如何决定两条可供选择的有性途径中的哪一条 差异化发展是一个根本性的问题。在C。 线虫，一种自由生活的土壤线虫，X染色体与X染色体组的比率 常染色体决定了有机体是否发育为自交受精 两性(2A：2X)或雄性(2A：1X)。此外，一组常染色体 对染色体平衡作出反应的基因已被确认为必需的 无论是两性的发育还是雄性的发育。 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，以及这一测量如何影响 性别决定基因和剂量补偿基因在下游 路径。一种方法是遗传方法，将雄性和两性分离。 已知与剂量有关的致死突变和基因抑制子 补偿。第二种方法是在以下位置执行描述性分析 间性动物的细胞水平，由突变或 通过改变X剂量。这一描述将在 想一想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，往往需要强加一个进一步的机制来确保 性染色体上的基因表达在不同的 性别。 2.另一个目的是了解剂量的作用机理。 补偿。我们的方法是从遗传和生化角度分析 已知的影响X连锁基因表达的基因座并识别新的 参与这一过程的基因座。生化分析包括化验 X连锁基因在疑似突变改变的动物中的表达 剂量补偿，以确定是否，事实上，他们做到了。在……里面 此外，分析还涉及到涉及到的基因座的分子克隆。 剂量补偿。

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.