CONTROL OF EPITHELIAL SHEET MOVEMENT IN C ELEGANS

了解上皮片是如何运动的，以及是什么控制了它们的运动 对于理解许多影响人类健康的事件来说， 包括胎儿发育和转移生长的控制 癌症。线虫的胚胎皮下组织是一种 研究上皮形态发生的强大模型系统。我们有 对影响皮下包膜的突变进行了筛查 具体方式，我们建议分析我们克隆的基因，以获得 更好地理解特定的分子损伤是如何识别的 蛋白质在单细胞分辨率下影响上皮的形态发生。这 该提案有四个主要目标： (1)确定连接素/钙粘附素同系物在封闭过程中的作用。我们 将分析HMP-1(一种阿尔法-1基因)突变胚胎中的特定缺陷。 连环蛋白)、HMP-2(一种β-连环蛋白)和HMR-1(一种钙粘附素) 突变体、马赛克和生殖系马赛克。我们还将测试 HMP-2通过建立多个转基因株系的形态发生作用 包含不能执行信令的各种嵌合结构 与β-连环蛋白相关的功能。 (2)明确类激动素蛋白Zen-4在封闭过程中的作用。 Zen-4编码一种类似于脊椎动物CHO1的动蛋白 抗原。我们将分析ZEN-4纯合子的外壳缺陷。最后， 我们将测试Zen-4蛋白是否以类似于 通过产生携带热激构建体的转基因株系获得CHO1Krp 并通过使用培养的细胞进行转基因实验。 (3)确定部分穿透性突变VAB-9在 封闭式。我们已经获得了VAB-9的宇宙飞船营救，这表明 胚胎和胚胎的外壳缺陷和其他形态发生异常 幼虫。我们将缩小救援区以确定编码的基因 VAB-9蛋白，通过产生试剂来表征其位置，并通过 检查与其他VAB的遗传交互作用。 (4)明确新突变在圈闭过程中的作用。我们有 部分表征了额外的突变，完全表明 穿透性封闭缺陷(合子缺陷、致命性缺陷、封闭缺陷、缺陷缺陷或禅宗 突变体)以及显示不完全穿透包涵体的突变 缺陷，以及其他形态形成过程中的缺陷(形态形成 上皮缺陷，或MED)。作为一个长期目标，我们将继续 几个新的ZEN和MED基因座的初步特征。 作为这些研究的结果，我们希望对 已识别分子中的特定损伤如何引起特定的 上皮形态发生过程中的细胞缺陷。

Understand how epithelial sheets move and what regulates their movement is fundamental for understanding many events impacting human health, including fetal development and the control of metastatic growth in cancer. The embryonic hypodermis of the nematode, C. elegans, is a powerful model system for studying epithelial morphogenesis. We have carried out a screen for mutations which affect hypodermal enclosure in specific ways, and we propose to analyze genes we have cloned to gain a greater understanding of how specific molecular lesions in identified proteins affect epithelial morphogenesis at single-cell resolution. This proposal has four major aims: (1) Defining the role of catenin/cadherin homologues during enclosure. We will analyze the specific defects in embryos mutant for hmp-1 (an alpha- catenin), hmp-2 (a beta-catenin), and hmr-1 (a cadherin) in multiple mutants, mosaics, and germline mosaics. We will also test the morphogenetic role of hmp-2 by creating several transgenic lines containing various chimeric constructs that cannot perform the signaling functions associated with beta-catenins. (2) Defining the role of the kinesin-like protein ZEN-4 during enclosure. zen-4 encodes a kinesin-like protein similar to the vertebrate CHO1 antigen. We will analyze enclosure defects in zen-4 homozygotes. Finally, we will test whether the ZEN-4 protein functions in a manner similar to the CHO1 KRP by generating transgenic lines carrying heat-shock constructs and by performing transfection experiments using cultured cells. (3) Defining the role of the partially penetrant mutation vab-9 during enclosure. We have obtained cosmid rescue of vab-9, which shows consistent enclosure defects and other morphogenetic abnormalities in embryos and larvae. We will narrow the rescuing region to identify the gene encoded by vab-9 protein, by generating reagents to characterize its location, and by examining genetic interactions with other vabs. (4) Defining the role of novel mutations during enclosure. We have partially characterized additional mutations that show completely penetrant enclosure defects (zygotic, lethal, enclosure, defective, or zen mutants) as well as mutations that show incompletely penetrant enclosure defects, and defects in other morphogenetic processes (morphogenesis of epithelial defective, or med). As a long-term goal, we will continue initial characterization of several novel zen and med loci. As a result of these studies, we expect to gain a greater understanding of how specific lesions in identified molecules give rise to specific cellular defects during epithelial morphogenesis.