Changes in gene expression in gills of the euryhaline killifish Fundulus heteroclitus after abrupt salinity transfer
Changes in gene expression in gills of the euryhaline killifish Fundulus heteroclitus after abrupt salinity transfer
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DOI：
10.1152/ajpcell.00054.2004
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发表时间：
2004-08-01
影响因子：
5.5
通讯作者：
Schulte, PM
中科院分区：
文献类型：
--
作者：
Scott, GR;Richards, JG;Schulte, PM
离子平衡的维持需要离子调节上皮在响应内部或环境渗透挑战时调节离子通量。我们已经探索了这种功能可塑性的基础上，在泛盐鳉的鳃底异克莱特。从近等渗微咸水[10份/千（ppt）]转移到淡水（FW）或海水（SW）后，定量了几个编码离子转运蛋白的基因的表达模式。响应SW传输的许多变化是短暂的。Na+- k +- atpase - α (1a)（3倍）、Na+- k +- 2cl(-)-共转运蛋白1 (NKCC1)（3倍）和糖皮质激素受体（1.3倍）mRNA表达增加，并与Na+- k +- atpase活性升高（2倍）并行。NKCC1 mRNA表达的短暂增加之后，NKCC蛋白丰度增加了2倍。与目前研究的其他基因相比，囊性纤维化跨膜传导调节因子（CFTR） Cl-通道的mRNA表达在SW中普遍升高（2倍）。然而，没有检测到蛋白质丰度的变化，提示转录后调控。对FW迁移的反应与对SW迁移的反应有较大差异。特别是FW转运比SW转运更能提高Na+-K+-ATPase- α (1a) mRNA表达和Na+-K+-ATPase活性，但对v型H+-ATPase表达没有影响，这支持了目前关于鳉鱼鳃通过Na+/H+交换转运Na+的观点。这些发现证明了盐度转移后离子转运蛋白在鳉鱼鳃中的独特表达模式，并阐明了离子转运上皮功能可塑性的重要机制。
Maintenance of ion balance requires that ionoregulatory epithelia modulate ion flux in response to internal or environmental osmotic challenges. We have explored the basis of this functional plasticity in the gills of the euryhaline killifish Fundulus heteroclitus. The expression patterns of several genes encoding ion transport proteins were quantified after transfer from near-isosmotic brackish water [10 parts/thousand (ppt)] to either freshwater (FW) or seawater (SW). Many changes in response to SW transfer were transient. Increased mRNA expression occurred 1 day after transfer for Na+-K+-ATPase-alpha(1a) (3-fold), Na+-K+-2Cl(-)- cotransporter 1 (NKCC1) (3-fold), and glucocorticoid receptor (1.3-fold) and was paralleled by elevated Na+-K+-ATPase activity (2-fold). The transient increase in NKCC1 mRNA expression was followed by a later 2-fold rise in NKCC protein abundance. In contrast to the other genes studied in the present work, mRNA expression of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel generally remained elevated (2-fold) in SW. No change in protein abundance was detected, however, suggesting posttranscriptional regulation. The responses to FW transfer were quite different from those to SW transfer. In particular, FW transfer increased Na+-K+-ATPase-alpha(1a) mRNA expression and Na+-K+-ATPase activity to a greater extent than did SW transfer but had no effect on V-type H+-ATPase expression, supporting the current suggestion that killifish gills transport Na+ via Na+/H+ exchange. These findings demonstrate unique patterns of ion transporter expression in killifish gills after salinity transfer and illustrate important mechanisms of functional plasticity in ion-transporting epithelia.