Genetic Analysis of Maternal Functions in Drosophila

对细胞决定早期事件的关键基因的详细分析是理解早期发育机制的最佳途径之一。果蝇的胚胎发育既需要母体基因产物，也需要合子基因产物。为了鉴定控制特定胚胎模式事件的基因，通过从女性不育筛选中分离出的突变来检测母体功能，而被母体储存的基因产物和具有特定母体效应致死表型的位点所掩盖的合子功能（与想象前致命性相关）无法通过这两种方法进行鉴定。为了描述这些基因座的功能，Perrimon博士之前已经成功地使用了种系镶嵌技术。由于技术原因，这些分析仅限于x染色体，但发现了大量在胚胎发育过程中起关键作用的新基因。本提案的目标是对位于第二和第三染色体（基因组的80%）上与特定母体效应致死表型相关的所有合子致死突变进行近饱和筛选。这些实验将提供由母体必需基因活动控制的各种过程的完整描述。此外，它们将为进一步详细分析胚胎发生过程中运作的各种模式系统提供基础。佩里蒙博士的实验室将重点研究新的终末基因的特征。此外，由于这些筛选将产生大量具有有趣表型的额外突变，因此突变集合将可供果蝇群落使用。从这些研究中产生的丰富信息将有助于我们对果蝇胚胎模式形成机制的总体理解，并将确定果蝇基因组编码的遗传功能。＊＊＊

9506237 Perrimon A detailed analysis of genes critical for early events in cellular determination is one of the best approaches to the understanding of the mechanics of early development. Embryonic development in Drosophila requires both maternal and zygotic gene products. To identify genes that control specific embryonic patterning events, maternal functions have been detected via mutations isolated from screens for female sterility, while zygotic functions which are masked by the maternally stored gene product and loci with specific maternal effect lethal phenotypes which are associated with pre- imaginal lethality cannot be identified using these two approaches. To characterize the function of such loci Dr. Perrimon has previously successfully used germline mosaic techniques. These analyses, which were limited to the X-chromosome for technical reasons, identified a large number of new genes that play critical roles during embryonic development. The goal of this proposal is to conduct near saturation screens for all zygotic lethal mutations located on the second and third chromosomes (80% of the genome) that are associated with specific maternal effect lethal phenotypes. These experiments will provide a complete description of the kinds of processes controlled by the maternal activity of essential genes. In addition, they will provide the foundation for further detailed analyses of various patterning systems that operate during embryogenesis. Dr. Perrimon's laboratory will focus on the characterization of new terminal class genes. In addition, since these screens will generate a large collection of additional mutations with interesting phenotypes, the collection of mutants will be made available to the fly community. The wealth of information generated from these studies will contribute to our general understanding of the mechanisms underlying embryonic pattern formation in Drosophila and will identify the genetic functions encoded by the Drosophila genome . ***