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之间的分界线。因此，上皮细胞覆盖在身体表面(例如皮肤)，并排列在器官的内腔(发现于肠、肺、肝脏等)。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。这一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重要调节因子。为了破译这种蛋白质的工作原理，我们以果蝇为模型生物。使用这个易于处理的遗传模型，我们将识别所有与Yrt相关的功能基因。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发现的dGir蛋白与Yrt合作使上皮细胞极化。另一方面，我们将在分析中确定的基因的细胞功能将突出Yrt控制极性的潜在机制。总体而言，我们的研究计划将为上皮组织的形态发生和生理学提供关键的见解，这对动物的发育、动态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.