Mechanisms and Regulation of Integumental Organic Solute Transport

水生动物的被膜在调节动物与环境之间有机化合物的交换中发挥着积极的作用，这一点越来越明显。在本项目中，PI将比较外皮和肠道营养物质运输的机制。这将是第一个整合这些营养收集器官中有机溶质运输特征的研究；并扩大了他们对无脊椎动物被膜和脊椎动物肠道中葡萄糖转运蛋白明显同源性的观察。他们还将首次研究盐度和养分有效性这两个重要环境因素的调控影响。考虑到最近的观察，这是特别令人兴奋的，第四氮化合物，甜菜碱，是由被皮热切地运输；这种转运体的表征尚未在任何上皮系统中报道，可能对当前甜菜碱及其相关化合物在脊椎动物和无脊椎动物渗透调节中的作用的研究产生重要影响。最后，PI建议开始研究被皮运输的发展，包括受精后发生的运输激活机制。所有这些研究的方法将结合使用完整的动物、分离的组织和亚细胞膜的制备，以及最近引入的几种用于运输蛋白质的分子探针，以及使用核磁共振作为研究细胞内溶质物理性质变化的工具。拟议的工作还包括两个主要门，软体动物和棘皮动物的被皮和肠道营养运输的比较检查。提出的工作检查营养吸收的调节由几个不同的器官系统在水生生物。这些研究包括对新受精卵中营养摄取激活的分子基础的第一次检查，然后跟踪这些过程的特定方面的发展，从卵到成虫的营养获取器官。这些结果将直接适用于了解几种具有重要商业价值的贝类的最佳生长条件。

It is increasingly apparent that the integument of aquatic animals can play an active role in mediating the exchange of organic compounds between animals and environment. In this project, the PI will compare the mechanisms of integumental and intestinal nutrient transport. This will represent the first study integrating the characteristics of organic solute transport in these nutrient gathering organs; and include an expansion of their observation of an apparent homology between glucose transporters in invertebrate integument and vertebrate intestine. They will also examine for the first time the regulatory influence of two significant environmental factors, salinity and nutrient availability. This is particulary exciting given the recent observation that the quaternary nitrogenous compound, betaine, is avidly transported by the integument; characterization of this transporter, which has not been reported in any epithelial system, could have an important impact on current studies of the role of betaine and related compounds in vertebrate and invertebrate osmoregulation. Finally, the PI proposes to begin study of the development of integument transport, including the mechanism of transport activation that occurs upon fertilization. The approach in all these studies will be to combine the use of intact animals, isolated tissues, and preparations of subcellular membranes, along with the introduction to this work of several recently introduced molecular probes for transport proteins as well as use of NMR as a tool for studying changes in the physical nature of intracellular solutes. The proposed work also includes a comparative examination of integumental and intestinal nutrient transport in two major phyla, the Mollusca and Echinodermata. The proposed work examines the regulation of nutrient uptake by several different organ systems in aquatic organisms. The studies include the first examination of the molecular basis of the activation of nutrient uptake into newly fertilized eggs, and then follows the development of particular aspects of these processes from egg to the nutrient acquiring organs of the adult. These results should be directly applicable to the understanding if optimal growing conditions for several species of commercially important shellfish.