MOLECULAR ANALYSES OF SEX DETERMINATION IN C ELEGANS

后生动物发育中的一个中心问题是细胞是如何 被调节以分化为一种细胞类型而不是另一种。 在 线虫C.细胞的性命运是由一种 少量的基因。 这些“性别决定”基因包括 全局控制基因，需要在所有组织中指定性别，以及 组织特异性控制基因。 我们建议研究其功能 以及3个全局（fem-1、fem-2和tra-2）和2个组织- 特定的（fog-1和fog-2）性别决定基因， 分子水平。 选择这些基因是因为它们是 生殖系组织中性命运的特化的核心 （精子或卵母细胞）。 克隆了这些基因之一tra-2（Okkema 和金布尔，未发表）;我们建议克隆其他人， 转座子标记 然后，我们将识别和描述他们的 我们会分析它们的DNA 序列和基因结构。 要么是基因改造，要么是 将使用瞬时测定来确认每个基因的身份。 我们的主要目标是研究 发育过程中的性别决定基因。 我们将测试 对性别决定控制途径的预测 根据遗传实验的结果提出，我们 将阐明基因之间的调控关系， 无法进行基因检测。 为了探索这条 控制，我们将研究性别决定的生产 其他性别决定基因突变体的转录本。 如果 如果转录物不受调节，则会产生针对 基因的蛋白质在这个水平上寻求调节。 此外，本发明还提供了一种方法， 这些基因之间的相互作用将通过瞬时 在显微注射到生殖系中后进行测定。 剂量效应将 通过使用转基因来增加额外的拷贝来进行研究。 特别是， 我们将研究可用的fog-1数量是否指定了 产生的精子数量。 最后， 将检查母体效应。 特别是，我们将研究 母亲的fem-1和fem-2如何只在 雌雄同体的生殖系，但在男性的所有组织。 这项工作的健康相关性源于其贡献 对线虫控制机制的理解 发展 这种控制的缺陷可能导致先天性 缺陷或癌症。 对线虫的认识 控制可能导致一种控制人类寄生虫的方法， 线虫

A central problem in metazoan development is how cells are regulated to differentiate as one cell type rather than another. In the nematode C. elegans, a cell's sexual fate is regulated by a small number of genes. These "sex-determination" genes include global control genes, required to specify sex in all tissues, and tissue-specific control genes. We propose to study the function and regulation of 3 global (fem-1, fem-2, and tra-2) and 2 tissue- specific (fog-1 and fog-2) sex-determination genes at the molecular level. These genes were selected because they are central to specification of the sexual fate in the germline tissue (sperm or oocyte). One of these genes, tra-2, is cloned (Okkema and Kimble, unpublished); we propose to clone the others by transposon tagging. Then, we will identify and characterize their transcripts during development and we will analyze their DNA sequence and gene structure. Either genetic transformation or a transient assay will be used to confirm the identity of each gene. Our primary goal is to investigate the regulation and function of the sex-determination genes during development. We will test the predictions of a pathway of sex determination control that has been proposed based on the results of genetic experiments and we will elucidate the regulatory relationships among genes that are not accessible to genetic tests. To explore this pathway of control, we will examine the production of sex-determination transcripts in mutants of other sex-determination genes. If transcripts are not regulated, antibodies will be produced to the genes' proteins to seek regulation at that level. In addition, interactions among these genes will be investigated by transient assay after microinjection into the germ line. Dosage effects will be studied by use of transgenes to add extra copies. In particular, we will study whether the amount of fog-1 available specifies the number of sperm produced. Finally, the molecular basis of maternal effects will be examined. In particular, we will study how maternal fem-1 and fem-2 directs the male fate only in the germline of hermaphrodites but in all tissues of males. The health relatedness of this work derives from its contribution to an understanding of mechanisms of control during nematode development. Defects in such controls may lead to congenital defects or cancer in humans. An understanding of nematode controls may lead to a method for the control of human parasitic nematodes.