CONTROL OF EPITHELIAL SHEET MOVEMENT IN C ELEGANS

了解上皮层如何移动以及调节其移动的因素 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， 癌线虫C. elegans是一个 用于研究上皮形态发生的强大模型系统。我们有 进行了一个突变的筛选，影响皮下封闭， 具体的方法，我们建议分析我们克隆的基因，以获得一个 更好地理解特定的分子病变是如何识别的 蛋白质影响单细胞分辨率的上皮形态发生。这 建议有四个主要目标： (1)确定连环蛋白/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（一种β-连环蛋白）和hMR-1（一种钙粘蛋白） 突变体、嵌合体和生殖系嵌合体。我们还将测试 通过建立几个转基因系来研究hmp-2的形态发生作用 含有各种嵌合构建体， 与β-连环蛋白相关的功能。 (2)定义驱动蛋白样蛋白ZEN-4在封闭过程中的作用。 zen-4编码类似于脊椎动物CHO 1的驱动蛋白样蛋白 抗原的我们将分析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 通过产生携带热休克构建体的转基因系， 以及通过使用培养的细胞进行转染实验。 (3)确定部分渗透突变vab-9在 附件。我们已经获得了vab-9的粘粒拯救，这表明了一致的 胚胎中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，以确定编码基因 vab-9蛋白，通过产生试剂来表征其位置， 检查与其他VAB的基因相互作用。 (4)定义新突变在圈地过程中的作用。我们有 部分表征的额外突变， 渗透性外壳缺陷（合子、致死、外壳、缺陷或zen 突变体）以及显示不完全渗透封闭的突变 缺陷和其他形态发生过程中的缺陷（ 上皮缺陷或MED）。作为长期目标，我们将继续 几个新zen和med位点的初步表征 作为这些研究的结果，我们希望能够更好地了解 已识别分子中的特定病变如何引起特定 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.