Investigations on the physiological role of C. elegans aquaporins.

在无脊椎生物中，水通道蛋白的功能和调控仍然是非常难以捉摸的。本课题的直接目的是揭示秀丽隐杆线虫（Caenorhabditis elegans）作为一种被广泛应用的模式生物，其上皮组织中水通道蛋白的生理意义。特别是，我们将确定水通道蛋白在渗透应激反应中的作用，以完成我们对秀丽隐杆线虫渗透调节过程和应激反应的了解。我们希望(1)测试水通道蛋白突变体或RNAi敲除动物的渗透胁迫抗性，以获得水通道蛋白在渗透胁迫条件下的生理作用信息；(2)分析急性和慢性渗透胁迫条件下上皮细胞表达的水通道蛋白mRNA和蛋白丰度的变化，以了解水通道蛋白的表达调节；(3)揭示在应激介导的水通道蛋白调节中重要的信号通路。(4)获取加压素信号通路对秀丽隐杆线虫水分平衡的影响。因此，我们可能揭示了加压素在秀丽隐杆线虫中的第一个生理功能，除了它最近在行为中所显示的作用。该项目还将有助于了解秀丽隐杆线虫分泌细胞的功能，并提供关于分泌细胞是否真的分泌甘油的信息。

In invertebrate organisms, functions and regulation of aquaporins are still quite elusive. The immediate aim of this project is to reveal the physiological significance of aquaporins in epithelial tissues of Caenorhabditis elegans which is widely used as a model organism. In particular, we will determine the role(s) of aquaporins in the response to osmotic stress in order to complete our picture on the osmoregulatory processes and the stress responses of C. elegans. We want to (1) test the osmotic stress resistance of aquaporin mutants or RNAi knock down animals to gain information about the physiological role of the aquaporin under osmotic stress conditions, (2) analyse changes of the mRNA and protein abundance of epithelial expressed aquaporins under acute and chronic osmotic stress conditions to understand the regulation of aquaporin expression, (3) reveal the signalling pathways that are important in stress-mediated aquaporin regulation, and (4) obtain information on the impact of the vasopressin signalling pathway on the water balance of C. elegans. Thereby, we may reveal the first physiological function of vasopressin in C. elegans, beside its recently demonstrated role in behaviour. This project will also help to understand the function of the excretory cell in C. elegans and provide information on whether glycerol is actually secreted by the excretory cell.