RUI: Molecular Regulation of Sodium Transport Systems in Euryhaline Animals

9407261根据定义，全盐动物能够在其水生环境中耐受广泛的盐水平。一个例子是绿岸蟹，这是世界上许多潮间带栖息地的一种引进物种。这种蟹通过调节自身血液中的盐分水平，成功地适应了一系列的环境盐度，这取决于它多功能鳃中的运输系统。蟹鳃中的两个钠转运体，钠/氢交换器和钠/钾泵，与哺乳动物肾脏中的转运体非常相似。如果我们能更多地了解绿蟹和其他广盐动物如何在自然条件下应对不同的盐负荷，也许我们就能更好地了解我们自己的肾脏的过程，这可能与高血压和其他体内平衡失调有关。我们也可以充分了解致癌的生理特性，从而提出将其作为一种有害生物加以控制的环保安全方法。托尔博士计划利用分子生物学技术研究螃蟹体内的两种钠转运体。他将使用聚合酶链反应（PCR）识别每个转运蛋白的遗传密码。确定每一种的DNA序列将允许与哺乳动物和其他脊椎动物的类似转运蛋白进行比较。他还将能够研究在不同盐度挑战下不同特化组织中每种转运蛋白的分子表达。他预计，在低盐环境下，这些转运蛋白将在动物的鳃中表达得最强烈，在这种环境下，盐的摄取将是适应性的。本研究将在森林湖学院和荒岛山生物实验室的本科生的协助下完成。＊＊＊

9407261 Towle Euryhaline animals by definition are capable of tolerating a broad range of salt levels in their aquatic environments. An example is the green shore crab Carcinus maenas, an introduced species in many intertidal habitats around the world. This crab succeeds in a range of environmental salinities by regulating its own salt levels in the blood, depending on transport systems in its multifunctional gills. Two sodium transporters in crab gill, a sodium/hydrogen exchanger and a sodium/potassium pump, are very similar to transporters in the mammalian kidney. If we can learn more about how the green crab and other euryhaline animals cope with varying salt loads under natural conditions, perhaps we will better understand processes in our own kidney which may be related to hypertension and other disorders of homeostasis. We may also learn enough about the specifics of the physiology of Carcinus to suggest environmentally safe approaches to its control as a pest species. Dr. Towle plans to study the two sodium transporters in the crab using the techniques of molecular biology. He will identify the genetic code for each of the transporters using the polymerase chain reaction (PCR). Determining the DNA sequence of each will permit a comparison with similar transporters in mammals and other vertebrates. He will also be able to study the molecular expression of each transporter in different specialized tissues under various salinity challenges. He expects that the transporters will be expressed most strongly in gills of animals challenged with low environmental salt, conditions in which salt uptake would be adaptive. The research will be accomplished with the assistance of undergraduates at Lake Forest College and Mount Desert Island Biological Laboratory. ***