不同盐度下“吉丽”罗非鱼(尼罗罗非鱼♀×萨罗罗非鱼♂)NKCC1a mRNA的组织特异性表达  

Tissue-specific changes of NKCC1a mRNA expression by salinity in "GILI" tilapia

作　　者：王兵[1] 范武江[1] 李思发[1] 

机构地区：[1]上海海洋大学,农业部水产种质资源与利用重点开放实验室,上海201306

出　　处：《中国水产科学》2011年第3期515-522,共8页Journal of Fishery Sciences of China

基　　金：国家科技支撑计划专题项目(2006BAD01A1203);罗非鱼行业技术体系(nycytx-48-3);公益性行业(农业)科研专项(nyhyzx07-044-01)

摘　　要：应用实时荧光定量PCR技术(qRT-PCR),以"吉丽"罗非鱼[尼罗罗非鱼(Oreochromis niloticus,♀)×萨罗罗非鱼(Sarotherodon melanotheron,♂)]为材料,研究NKCC1a基因表达的盐度组织特异性。研究结果表明:(1)NKCC1a基因mRNA表达量存在显著的组织特异性,在低于25盐度环境中,NKCC1a mRNA在鳃、肝、肾及肠中均有表达;当盐度从0提高到48时,表达量在鳃中与盐度变化呈高度正相关(R>0.9,P<0.01),在肠和肾中与盐度变化呈负相关(R≈0.7,P<0.05),但在肝中则不受盐度变化的影响。(2)当盐度提高到64,NKCC1a基因mRNA表达量在鳃和肠3 h后达最高值,5 h后下降,前后变化差异显著(P<0.05);表达量在肝中则是在5 h后达最高值,变化差异也显著(P<0.05);表达量在肾中持续下降,但差异不显著。以上结果揭示,在盐度高于25的环境中,"吉丽"罗非鱼主要由鳃组织的NKCC1a排出多余的离子以维持鱼体的水盐平衡,由此认为鳃组织在"吉丽"罗非鱼高渗透压调节中起最主要作用。In this paper, Quantitative real-time reverse transcription-polymerase chain reaction （qRT-PCR） was used to study the tissue-specific changes of NKCClα mRNA expression by salinity in case of the hybrid（named “GILI” tilapia）by Oreochromis niloticus（ ♀ ）xSarotherodon melanotheron（♂）. As a new variety ,“GILI” tilapia characterized by high salt tolerance and fast growth is suitable for marine culture. The present results showed that： （1） The NKCCIa mRNA expression level has significant tissue specificity. The NKCCla gene expressed in all tested tissues of gill, liver, kidney and intestine under salinity below 25. When the salinity increased from 0 to 48, the NKCCla mRNA expression level showed a positive correlation with salinity in gill （R〉0.9, P〈0.01）, but negative correlation in intestine and kidney （R≈-0.7, P〈0.05） and no significant correlation in liver（P〉0.05）. （1）When the salinity raised to 64, the mRNA expression level reached the highest peak after 3 h in gill and intestine, and decreased after 5 h, and there were significant differences between 1 h and 3 h, and between 3 h and 5 h （P〈0.05）. In liver, the maximum level appeared in 5 h and significantly higher than those in 1 h and 3 h（P〈0.05）. In kidney, the expression levels descended continually with the increase of exposure time, but no significant differences were detected in different time（P〉0.05）. Above results revealed that, in the “GILI” fish which acclimates to environmental salinity over 25, it is primarily the gill chloride cells to secrete the cation ions and to maintain water and salt balance. So, it could be considered that gill plays a leading role in osmoregulation of “GILI” tilapia. Meanwhile, it is expected to revealing the expression mode of NKCCIa gene in euryhaline teleosts in fresh, saline and hypersaline water.

关 键 词：罗非鱼 NKCC1a基因 mRNA表达 组织特异性 盐度 

分 类 号：S917[农业科学—水产科学]