CONTROL OF EPITHELIAL SHEET MOVEMENT IN C ELEGANS

了解上皮片如何移动以及调节其移动的因素是什么 对于理解许多影响人类健康的事件至关重要， 包括胎儿发育和转移生长的控制 癌症。线虫（C. elegans）的胚胎皮下组织是 用于研究上皮形态发生的强大模型系统。我们有 对影响皮下包络的突变进行了筛选 具体方法，我们建议分析我们克隆的基因以获得 更好地了解如何识别特定的分子病变 蛋白质在单细胞分辨率下影响上皮形态发生。这个 提案有四个主要目标： (1) 定义连环蛋白/钙粘蛋白同源物在封闭过程中的作用。我们 将分析 hmp-1（一种 α- 连环蛋白）、hmp-2（β-连环蛋白）和 hmr-1（钙粘蛋白）在多个 突变体、嵌合体和种系嵌合体。我们还将测试 通过创建几个转基因系来研究 hmp-2 的形态发生作用 含有各种不能执行信号传导的嵌合结构 与 β-连环蛋白相关的功能。 (2) 定义类驱动蛋白ZEN-4在封闭过程中的作用。 zen-4 编码类似于脊椎动物 CHO1 的驱动蛋白样蛋白 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 通过生成携带热休克构建体的转基因系来构建 CHO1 KRP 并使用培养细胞进行转染实验。 (3) 定义部分渗透突变vab-9在过程中的作用 外壳。我们获得了vab-9的cosmid救援，这表明它是一致的 胚胎的外壳缺陷和其他形态发生异常 幼虫。我们将缩小拯救区域以鉴定编码的基因 vab-9 蛋白，通过生成试剂来表征其位置，并通过 检查与其他 vab 的遗传相互作用。 (4) 定义封闭过程中新突变的作用。我们有 部分表征的额外突变完全显示 渗透性外壳缺陷（合子、致命、外壳、缺陷或禅宗） 突变体）以及显示不完全渗透封闭的突变 缺陷，以及其他形态发生过程中的缺陷（形态发生 上皮缺陷，或医学）。作为一个长期目标，我们将继续 几个新颖的禅宗和医学基因座的初步表征。 通过这些研究，我们希望能够更深入地了解 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.