U.S.-France Cooperative Research: Transcriptional and Posttranscriptional Regulation of the Sodium Pump

许多沿海生境包括河口，其中淡水和海水的混合形成了受潮汐循环和降雨影响的盐度梯度。一些植物和动物已经进化出生理机制，使它们能够在如此紧张的环境中成功繁殖。其中包括水生甲壳类动物，如海岸蟹，以及其他如绿蟹和亚洲蟹，它们在缺乏天敌的生态系统中具有高度入侵性。我们假设这些动物通过调节(1)特定基因的表达和(2)这些基因编码的蛋白质的功能来抵抗盐度的变化。我们建议在潮间带河口环境中非常成功的岸蟹Pachygrapsus marmoratus中检验这一假设。像许多广盐蟹一样，这个物种能够从稀释的盐度中吸收盐，利用钠泵为这个过程提供能量。然而，P. marmoratus也能够在比正常海水更集中的环境中排泄盐。我们的目的是描述导致钠泵基因表达差异的步骤，重点是神经激素因素和细胞信号通路。拟议的研究将增加东道国（Mount Desert Island生物实验室）和对口单位（法国蒙彼利埃第二大学）的培训机会。法国实验室将学习额外的分子技术，而东道国实验室将获得电生理学和鳃灌注方面的专业知识。拟议研究的一个重要部分是从缅因州大学招募的本科生的参与，他们将在两国合作进行拟议的研究。

Many coastal habitats include estuaries in which the mixing of fresh water and seawater establishes a salinity gradient affected by tidal cycles and rainfall. A few species of plants and animals have evolved physiological mechanisms that permit reproductive success in such stressful environments. Among these are aquatic crustaceans like the shore crab Pachygrapsus marmoratus and others such as the green crab Carcinus maenas and the Asian crab Hemigrapsus sanguineus that are highly invasive in ecosystems where they lack natural predators. We hypothesize that these animals resist changes in salinity by regulating (1) the expression of specific genes and (2) the function of proteins encoded by those genes. We propose to examine this hypothesis in the shore crab Pachygrapsus marmoratus, a highly successful species in intertidal estuarine environments. Like many euryhaline crabs, this species is capable of taking up salt from dilute salinities, using the sodium pump to energize the process. However, P. marmoratus is also capable of salt excretion in environments more concentrated than normal seawater. Our aim is to delineate the steps leading to differences in sodium pump gene expression, with emphasis on neurohormonal factors and cell signaling pathways. The proposed research will lead to enhanced training opportunities for both the host (Mount Desert Island Biological Laboratory) and counterpart (Universite Montpellier II, France). The French lab will learn additional molecular techniques while the host lab will gain expertise in electrophysiology and gill perfusion. An important part of the proposed research is the involvement of undergraduates, to be recruited from Maine colleges, who will collaborate in the proposed research in both countries.