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

许多沿海生境包括河口，在河口，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。一些种类的动植物进化出了生理机制，使它们能够在这种紧张的环境中繁殖成功。其中包括水生甲壳类动物，如海蟹Pachygrapsus marmoratus，以及其他一些水生甲壳类动物，如青蟹Carcinus maenas和亚洲蟹Haligrapsus sanguineus，它们在缺乏自然捕食者的生态系统中具有高度侵袭性。我们假设，这些动物通过调节(1)特定基因的表达和(2)由这些基因编码的蛋白质的功能来抵抗盐度的变化。我们建议在海岸蟹类Pachygrapsus marmoratus中检验这一假设，Pachygrapsus marmoratus是一种在潮间带河口环境中非常成功的物种。像许多真盐蟹一样，这一物种能够利用钠泵为这个过程提供能量，从而从稀释的盐分中吸收盐分。然而，在比正常海水更密集的环境中，P.marmoratus也能够排盐。我们的目的是描绘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主(荒漠岛生物实验室)和对口单位(法国蒙彼利埃第二大学)的培训机会。法国实验室将学习其他分子技术，而东道主实验室将获得电生理学和鳃灌流方面的专业知识。这项拟议研究的一个重要部分是让将从缅因州大学招聘的本科生参与，他们将在两国合作开展拟议的研究。

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.