GENETIC CONTROL OF NEMATODE DEVELOPMENT

小型土壤线虫--线虫的发育 优雅包含一个不变的和精确已知的时间 细胞分裂和分化事件的模式或顺序。 这项工作的长期目标是阐明这种暂时的 发育时间表是由基因编码的。这位将军 需要解决的问题是：1)个人的角色是什么 控制发育事件时间序列的基因？ 2)这些基因的组织和阶段特异性是什么？ 3)编码细胞固有的基因与 阐述和解释时间的细胞--外在功能 发育过程中的信息？4)这些基因是如何 它们之间以及与控制基因的功能相互作用 基本的细胞过程，如细胞分裂和分化？ 突变株的遗传和表型特性 发育的时间模式(“异时突变”)将 将被详细研究。将尝试通过以下方式确定 突变控制和执行特定基因的所有基因 细胞命运中的时间转换--幼虫程序的转换 (细胞分裂和幼虫角质层合成)到成虫程序(成虫 角质层合成)用于皮下“缝隙”细胞。对于每个新的 已识别的基因，以及之前已识别的八个基因中的某些 影响这一开关的基因，将进行详细的遗传分析 应用于确定它们各自的空表型，从而 它们在野生型发育中的作用。功能交互将 通过构建已知的多重突变株来探索 两个或两个以上异型慢性基因的遗传损伤。 利用温敏技术进行温度漂移实验 等位基因将被用来研究每个基因的作用时间。 更多的突变体将被寻找有缺陷的 后期开发的时机。基因So的遗传分析 将进行鉴定。基因转录阶段- 具体地说，和/或具体地说在邮政或 非多德发育将通过探测重组人来识别 用cDNA探针构建噬菌体文库。这些基因的序列 将被用来分析异时突变对 特定发育相关基因的表达 程序。

The development of the small soil nematode Caenorhabditis elegans involves an invarient and precisely known temporal pattern or sequence of cell divisions and differentation events. The long term goal of this work is to elucidate how this temporal schedule of development is genetically encoded. The general questions to be addressed are: 1) What are the roles of individual genes in controlling temporal sequences of developmental events? 2) What are the tissue- and stage-specificities of those genes? 3) What are the relative roles of genes encoding cell-intrinsic vs cell-extrinsic functions in elaborating and interpreting temporal information during development? 4) How do these genes functionally interact among themselves and with genes controlling basic cellular processes such as cell division and differentiation? The genetic and phenotypic properties of mutants with altered temporal patterns of development ("heterochronic mutants") will be studied in detail. An attempt will be made to identify by mutation all genes involved in controlling and executing a specific temporal switch in cell fate - the switch from larval programs (cell division and larval cuticle synthesis) to adult program (adult cuticle synthesis) for hypodermal "seam" cells. For each newly identified gene, and for certain of the eight previously identified genes affecting this switch, detailed genetic analysis will be applied to determine their respective null phenotypes and thus their roles in wild-type development. Functional interactions will be explored by constructing multiply-mutant strains with known genetic lesions in two or more hetero-chronic genes. Temperature shift experiments using temperature-sensitive alleles will be used to investigate the time of action of each gene. Additional mutants will be sought defective specifically in the timing of postdauer development. Genetic analysis of genes so identified will be carried out. Genes transcribed stage- specifically, and/or specifically during either postdauer or nondauer development will be identified by probing recombinant phage libraries with cDNA probes. The sequences of these genes will be used to analyze the effects of heterochronic mutations on the expression of genes involved in specific developmental programs.