Genetic Analysis of Epithelial Morphogenesis and Organ Shape

描述（由申请人提供）：本研究的长期目标是确定细胞形状、极性和细胞群间粘附的动态调节如何在发育过程中塑造器官的形状。为此，我们正在果蝇中使用遗传和细胞生物学方法来研究滤泡细胞上皮内一种新形式的平面极性如何形成一个简单的器官样单位（称为卵室）的细长形状。平面极性是一种发育机制，其中单个细胞在组织平面内协调极化，为随后的形态发生事件提供方向信息。对苍蝇翅膀和眼睛中这种现象的开创性工作导致了卷曲平面细胞极性通路的发现，现在已知该通路形成脊椎动物体轴、内耳、肾脏和神经管。然而，卷曲信号盒在卵室伸长中没有作用，这表明对这一过程的研究可能会定义一个新的，也许类似的保守分子框架，调节平面极性和器官形状。我们的前两个具体目标是为了阐明这种非传统的平面极性系统的细胞机制。目的1将使用遗传操作来测试一种称为极性细胞的专门细胞类型在相邻毛囊细胞中诱导平面极性的假设，而目的2将使用固定和实时成像技术来探索极化细胞的发育和功能，该极化细胞的发育和功能代表了该组织中平面极性的最引人注目的形态学读数。为了补充这些细胞分析，我们进行了一项试点遗传筛选，确定了一个关键的分子途径调节平面图案和形态发生在这个上皮。目标3将使用遗传和生物化学方法来研究这种信号级联的功能，目标4将采用高效的筛选策略，将对新型蛋形调节剂的研究扩展到果蝇基因组的其他区域。这些研究将揭示控制卵泡细胞平面极性和卵腔伸长的细胞和分子机制，并可能揭示在广泛的系统中指导器官形态发生的一般原则。 公共卫生相关性：重要器官的正常功能要求它们在胚胎发育期间达到其适当的形状。当这些过程出错时，就会导致出生缺陷和代谢性疾病。本研究的目的是利用果蝇的实验易处理性来揭示指导器官形态发生的新的细胞和分子机制。

DESCRIPTION (provided by applicant): The long term goal of this research is to determine how the dynamic regulation of cell shape, polarity and adhesion across cell populations sculpts an organ's shape during development. To this end, we are using genetic and cell biological approaches in Drosophila to investigate how a novel form of planar polarity within the follicle cell epithelium creates the elongated shape of a simple organ-like unit known as an egg chamber. Planar polarity is a developmental mechanism in which individual cells are coordinately polarized within the plane of a tissue to provide directional information for subsequent morphogenetic events. Pioneering work on this phenomenon in the fly wing and eye led to the discovery of the Frizzled planar cell polarity pathway, which is now known to shape the vertebrate body axis, inner ear, kidneys and neural tube. The Frizzled signaling cassette plays no role in egg chamber elongation, however, indicating that the investigation of this process is likely to define a new and perhaps similarly conserved molecular framework regulating planar polarity and organ shape. Our first two specific aims are designed to elucidate the cellular mechanisms that underlie this unconventional planar polarity system. Aim 1 will use genetic manipulations to test the hypothesis that a specialized cell type known as the polar cells induces planar polarity in the neighboring follicle cells, while Aim 2 will use fixed and live imaging techniques to explore the development and function of a polarized cell protrusive activity that represents the most dramatic morphological readout of planar polarity in this tissue. To complement these cellular analyses, we performed a pilot genetic screen that identified a key molecular pathway regulating planar patterning and morphogenesis in this epithelium. Aim 3 will use genetic and biochemical approaches to investigate the function of this signaling cascade, and Aim 4 will employ a highly efficient screening strategy to extend the search for novel egg shape regulators to other regions of the Drosophila genome. Together these studies will reveal the cellular and molecular mechanisms controlling follicle cell planar polarity and egg chamber elongation, and are likely to reveal general principles guiding organ morphogenesis in wide range of systems. PUBLIC HEALTH RELEVANCE: The proper function of vital organs requires that they attain their proper shapes during embryonic development. When these processes go awry, birth defects metabolic diseases result. The goal of this research is to use the experimental tractability of fruit flies to reveal novel cellular and molecular mechanisms guiding organ morphogenesis.