The Legs Have It: In Situ Expression of Ion Transporters V-Type H + -ATPase and Na + /K + -ATPase in the Osmoregulatory Leg Organs of the Invading Copepod Eurytemora affinis
The Legs Have It: In Situ Expression of Ion Transporters V-Type H + -ATPase and Na + /K + -ATPase in the Osmoregulatory Leg Organs of the Invading Copepod Eurytemora affinis
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腿部有它：离子转运蛋白 V 型 H -ATP 酶和 Na /K -ATP 酶在入侵桡足类 Eurytemora affinis 的渗透调节腿部器官中的原位表达
DOI：
10.1086/686323
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发表时间：
2016
影响因子：
1.6
通讯作者：
Charmantier, Guy
中科院分区：
文献类型：
--
作者：
Gerber, Lucie;Lee, Carol Eunmi;Grousset, Evelyse;Blondeau-Bidet, Eva;Boucheker, Nesrine Boudour;Lorin-Nebel, Catherine;Charmantier-Daures, Mireille;Charmantier, Guy
桡足动物Eurytemora affinis具有异常广泛的盐度范围，因为一些种群最近独立于其祖先的盐水栖息地入侵淡水栖息地。先前的研究表明，在淡水入侵过程中，离子转运体的活性发生了进化变化，并在游泳腿部新发现的“Crusalis器官”中发现了离子转运体的定位。本研究的目的是定位和量化离子转运酶v型H+- atp酶（VHA）和Na+/K+- atp酶（NKA）在亲和鲈游动腿中的表达，并确定每条腿参与离子调节的程度。我们证实在Crusalis器官中存在两种不同类型的离子细胞。两种细胞类型均表达VHA和NKA，在淡水种群中，VHA和NKA分别位于离子细胞的顶端和基部。通过对NKA和VHA原位表达的定量分析，确定了游腿3和游腿4在咸水和淡水种群中离子转运中的优势。淡水种群（在淡水中）与盐水种群（在15 PSU时）相比，游泳腿3和4中VHA表达的增加是由于每个细胞VHA丰度的增加，而不是离子细胞数量的增加。这一结果提示了一种增加淡水离子吸收的简单机制。相比之下，淡水种群中NKA表达的下降是由于腿4的离子细胞面积减少，可能是由于含有NKA的离子细胞的数量或大小减少。这些结果为该物种的离子调节机制提供了见解，并进一步了解了栖息地入侵期间生理适应的进化机制。
The copepod Eurytemora affinis has an unusually broad salinity range, as some populations have recently invaded freshwater habitats independently from their ancestral saline habitats. Prior studies have shown evolutionary shifts in ion transporter activity during freshwater invasions and localization of ion transporters in newly discovered “Crusalis organs” in the swimming legs. The goals of this study were to localize and quantify expression of ion transport enzymes V-type H+-ATPase (VHA) and Na+/K+-ATPase (NKA) in the swimming legs of E. affinis and determine the degree of involvement of each leg in ionic regulation. We confirmed the presence of two distinct types of ionocytes in the Crusalis organs. Both cell types expressed VHA and NKA, and in the freshwater population the location of VHA and NKA in ionocytes was, respectively, apical and basal. Quantification of in situ expression of NKA and VHA established the predominance of swimming leg pairs 3 and 4 in ion transport in both saline and freshwater populations. Increases in VHA expression in swimming legs 3 and 4 of the freshwater population (in fresh water) relative to the saline population (at 15 PSU) arose from an increase in the abundance of VHA per cell rather than an increase in the number of ionocytes. This result suggests a simple mechanism for increasing ion uptake in fresh water. In contrast, the decline in NKA expression in the freshwater population arose from a decrease in ionocyte area in legs 4, likely resulting from decreases in number or size of ionocytes containing NKA. Such results provide insights into mechanisms of ionic regulation for this species, with added insights into evolutionary mechanisms underlying physiological adaptation during habitat invasions.