Epithelial tissue morphogenesis in metazoans

由上皮细胞组成的上皮细胞界定了复杂生物体外部环境和内部之间的边界。因此，上皮细胞覆盖身体的表面（例如皮肤），并在器官的内腔（在肠，肺，肝等中发现）中排列。上皮细胞的一个重要功能是选择性地运输分子，例如从肠腔向血流运输营养物质。这种功能依赖于许多细胞成分的不对称分布，这是一种称为上皮极性的结构组织。上皮细胞的极化结构也塑造器官和动物。我们发现Yrt蛋白是上皮细胞极性的重要调节因子。为了解释这种蛋白质是如何工作的，我们使用果蝇作为模式生物。利用这个易处理的遗传模型，我们将鉴定所有与yrt功能相关的基因。一方面，这将突出上皮细胞极化所需的其他基因。作为原理的证明，我们证明了在我们的初步研究中鉴定的蛋白质dGir与Yrt合作来抑制上皮细胞。另一方面，在我们的分析中待鉴定的基因的细胞功能将突出Yrt可以控制极性的潜在机制。总的来说，我们的研究计划将为上皮组织的形态发生和生理学提供重要的见解，这对动物的发育，稳态和生存至关重要。

Epithelia, composed of epithelial cells, delimit the frontier between the external environment and the inside of complex organisms. Therefore, epithelial cells cover the surface of the body (e.g. skin) and line internal cavities of organs (found in the intestine, lungs, liver, etc). An important function of epithelia is to selectively transport molecules, for instance nutrients from the intestinal lumen toward the bloodstream. This function relies on the asymmetric distribution of many cellular constituents, a structural organization referred to as epithelial polarity. The polarized architecture of epithelial cells also shapes organs and animals. We discovered that the protein Yrt is a crucial regulator of epithelial cell polarity. To decipher how this protein works, we use the fruit fly as model organism. Using this tractable genetic model, we will identify all genes functionally related to yrt. On the one hand, this will highlight other genes required for epithelial cell polarization. As a proof of principle, we showed that the protein dGir, which was identified in our pilot study, cooperates with Yrt to polarize epithelial cells. On the other hand, the cellular functions of the genes to be identified in our analysis will highlight potential mechanisms through which Yrt could control polarity. Overall, our research program will provide crucial insights into morphogenesis and physiology of epithelial tissues, which are crucial for animal development, homeostasis and survival.