Epithelial tissue morphogenesis in metazoans

上皮由上皮细胞组成，是复杂生物体内部和外部环境的分界线。因此，上皮细胞覆盖在身体表面（如皮肤），排列在器官的内腔（在肠、肺、肝等）。上皮细胞的一个重要功能是选择性地将分子，例如营养物质从肠腔输送到血液中。这种功能依赖于许多细胞成分的不对称分布，这种结构组织被称为上皮极性。上皮细胞的极化结构也塑造了器官和动物。我们发现Yrt蛋白是上皮细胞极性的关键调节因子。为了解释这种蛋白质是如何工作的，我们用果蝇作为模式生物。利用这个可处理的遗传模型，我们将确定与yrt功能相关的所有基因。一方面，这将突出上皮细胞极化所需的其他基因。作为原理证明，我们发现在我们的前期研究中鉴定的dGir蛋白与Yrt合作使上皮细胞极化。另一方面，在我们的分析中鉴定的基因的细胞功能将突出通过Yrt控制极性的潜在机制。总的来说，我们的研究项目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、体内平衡和生存至关重要。

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.