MOLECULAR GENETICS OF EMBRYONIC POLARITY IN DROSOPHILA

多细胞生物的前后位测定 (A-P)胚胎的极性是随后 发展，因为整个身体计划是相对于 这条轴。目前对其分子机制知之甚少。 建立了哪个胚胎的极点以及轴向信息 被转换成细胞的命运。遗传和分子分析已经 显示出许多指定胚胎极性的分子 和花纹是在卵巢卵泡中母性合成的。 黑腹果蝇是一种极好的有机体，可以在其中 对发育现象进行突变分析以 在分子水平上，也具有独特的优势 卵子发生的研究。这项提案旨在分析基因和 果蝇卵子发生过程中所需的四个基因座 胚轴前后部的形成：躯干(9 等位基因)、剪接(1个等位基因)、外显(4个等位基因)和二头(1个 等位基因)。这四个基因座的突变表型加在一起 涵盖了所有的表型异常 大约有20个基因座参与建立A-P轴，以及 对突变组合的分析表明，它们的基因产物 形成一个相互作用的分子系统的一部分，涉及 指定胚胎的极性。基因分析将被用于 详细描述现有的和新分离的等位基因 并对它们进行高分辨率的细胞遗传学定位。这个 分子分析将集中在发现最多的 在基因上很有趣，在分子上也很容易处理。这个 转录的结构，它们的空间分布和蛋白质- 编码潜力将被确定。与已知同源 蛋白质可能暗示了编码的蛋白质的功能和酶的作用 蛋白质。随后会产生抗融合的抗血清。 蛋白质，用于分析空间和时间表达 克隆基因的蛋白质产物。评选结果 基因产物的空间分析将具有重要的意义 关系到普遍的发育和细胞生物学问题 空间不对称是如何在细胞中建立的，以及将 限制可能的图案形成的分子模型。在 从长远来看，基因产物和它们的生物化学研究 活动和互动，应该提供机械性的见解 成为发展的核心过程之一 多细胞生物。

In multicellular organisms the determination of anterior-posterior (A-P) embryonic poloarity is fundamental to subsequent development since the entire body plan is constructed relative to this axis. Little is known about the molecular mechanisms by which embryonic polarity is established and how axial information is transduced into cell fate. Genetic and molecular analyses have shown that many of the molecules that specify embryonic polarity and pattern are synthesized maternally in the ovarian follicies. Drosophila melanogaster is an excellent organism in which to pursue the mutational analysis of developmental phenomena to the molecular level and also possesses specific advantages for the study of oogenesis. This proposal aims to analyze genetically and molecularly four loci in Drosophila required during oogenesis for the formation of the anterior-posterior embryonic axis: torso (9 alleles), spliced (1 allele), exuperantia (4 alleles) and dicephalic (1 allele). Together, the mutant phenotypes of these four loci encompass the entire range of phenotypic abnormalities of the roughly twenty loci involved in establishing the A-P axis, and analyses of mutant combinations suggest that their gene products form part of an interacting system of molecules involved in specifying embryonic polarity. Genetic analysis will be used to characterize in detail existing and newly isolated alleles at these loci and to map them at high resolution cytogenetically. The molecular analyses will focus on the loci found to be most interesting genetically as well as most tractable molecularly. The structure of the transcripts, their spatial distribution and protein- coding potential will be determined. Homologies to known proteins may suggest functional, enzymatic roles for the encoded proteins. Subsequently, antisera will be raised against fusion proteins and used to analyze the spatial and temporal expression of the protein products of the cloned genes. The results of the spatial analyses of the gene products will have an important bearing on the general developmental and cell biological problem of how spatial asymmetries are established in cells, and will constrain possible molecular models of pattern formation. In the longer term, biochemical studies of the gene products and their activities and interactions, should provide mechanistic insights into one of the central processes in the development of multicellular organisms.