Pituitary control of branchial NCC, NKCC and Na(+), K (+)-ATPase α-subunit gene expression in Nile tilapia, Oreochromis niloticus
Pituitary control of branchial NCC, NKCC and Na(+), K (+)-ATPase α-subunit gene expression in Nile tilapia, Oreochromis niloticus
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尼罗罗非鱼鳃NCC、NKCC和Na(+)、K(+)-ATP酶α亚基基因表达的垂体控制
DOI：
10.1007/s00360-014-0817-0
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发表时间：
2014
期刊：
影响因子：
2
通讯作者：
Grau EG
中科院分区：
文献类型：
--
作者：
Breves JP;Seale AP;Moorman BP;Lerner DT;Moriyama S;Hopkins KD;Grau EG
本研究探讨了催乳素（prl188和Prl177）、生长激素（Gh）和皮质醇对尼罗罗非鱼鳃离子调节功能的内分泌调控作用。Na+/Cl -共转运体（ncc）和Na+/K+/2Cl -共转运体（nkcc）基因的分支表达分别作为淡水型和海水型离子细胞的特异性标记。我们进一步研究了Prl、Gh和皮质醇是否直接表达Na+， K+- atp酶(nka)-α1亚基基因（nka -α1aandnka-α1b）。罗非鱼垂体切除后转移到淡水中不能充分激活gillncc表达；随后通过替换Prl恢复ncc表达。prl188和prl177在培养的鳃丝中以浓度相关的方式刺激ncc1的表达，表明ncc1受Prl以鳃自主方式调节。罗非鱼在垂体切除术后转入半咸淡水（23‰），其上调enka-α1表达的能力降低。而Gh和皮质醇在体内不影响tnka-α1的表达。同样，我们在体内和体外均未发现Gh或皮质醇对nkcc2表达的明显影响。当考虑到以前在泛盐莫桑比克罗非鱼（O. mossambicus）中描述的模式时，当前的研究表明，ncci是罗非鱼鲷中Prl的保守靶点。此外，我们还揭示了尼罗罗非鱼和莫桑比克罗非鱼在高渗环境中对垂体直接α1表达的依赖性。
This study investigated endocrine control of branchial ionoregulatory function in Nile tilapia (Oreochromis niloticus) by prolactin (Prl188and Prl177), growth hormone (Gh) and cortisol. Branchial expression of Na+/Cl−cotransporter (ncc) and Na+/K+/2Cl−cotransporter (nkcc) genes were employed as specific markers for freshwater- and seawater-type ionocytes, respectively. We further investigated whether Prl, Gh and cortisol direct expression of two Na+, K+-ATPase (nka)-α1 subunit genes, denotednka-α1aandnka-α1b. Tilapia transferred to fresh water following hypophysectomy failed to adequately activate gillnccexpression;nccexpression was subsequently restored by Prl replacement. Prl188and Prl177stimulatednccexpression in cultured gill filaments in a concentration-related manner, suggesting thatnccis regulated by Prl in a gill-autonomous fashion. Tilapia transferred to brackish water (23 ‰) following hypophysectomy exhibited a reduced capacity to up-regulatenka-α1bexpression. However, Gh and cortisol failed to affectnka-α1bexpression in vivo. Similarly, we found no clear effects of Gh or cortisol onnkccexpression both in vivo and in vitro. When considered with patterns previously described in euryhaline Mozambique tilapia (O. mossambicus), the current study suggests thatnccis a conserved target of Prl in tilapiine cichlids. In addition, we revealed contrasting dependencies upon the pituitary to directnka-α1bexpression in hyperosmotic environments between Nile and Mozambique tilapia.