尼罗罗非鱼、萨罗罗非鱼及其杂交子代的催乳素Ⅰ基因克隆及序列分析  

PRLI gene cloning and sequence analysis of Oreochromis niloticus,Sarotherodon melanotheron and their hybrid

作　　者：孟庆辉[1] 李思发[1] 范武江[1] 王兵[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》2010年第3期414-423,共10页Journal of Fishery Sciences of China

基　　金：国家科技支撑计划专题(2006BAD01A1203);罗非鱼产业技术体系(新D-8002-09-0055);公益性行业(农业)科研专项(nyhyzx07-044-01)

摘　　要：本研究采用RT-PCR方法对生长快、耐盐性弱的尼罗罗非鱼(Oreochromis niloticus),耐盐性强、生长慢的萨罗罗非鱼(Sarotherodon melanotheron)以及生长与耐盐均较优的杂交子代(O.niloticus♀×S.melanotheron♂)的催乳素PRLI基因cDNA序列片段进行了克隆与序列分析,以探讨罗非鱼耐盐性的分子机制,分析和筛选与耐盐性相关的基因。主要结果:(1)序列克隆及ClustalX1.83分析表明克隆所得cDNA序列长度为339bp,编码112个氨基酸。(2)3种罗非鱼PRLI的cDNA具有高度的保守性,核苷酸序列同源性介于97.94%～99.71%之间,氨基酸序列同源性均在99.11%以上,表明罗非鱼的PRLI基因具有高度保守性。(3)杂交子代同尼罗罗非鱼的cDNA序列相比有5个碱基的变异,变异比例为1.47%;同萨罗罗非鱼相比有1个碱基的变异,变异比例为0.30%。(4)尼罗罗非鱼推导氨基酸序列中第80位氨基酸残基为脯氨酸残基(P),而杂交子代和萨罗罗非鱼在该位点均为丝氨酸残基(S)。(5)MEGA4系统进化树分析显示,杂交子代同萨罗罗非鱼聚为1支。结果(3)、(4)、(5)表明,在PRLI基因的表达方面,杂交子代同父本萨罗罗非鱼的关系较近。PRLI is an important osmoregulation hormone, which belongs to GH/PRL/SL hormone family. Its most important role in tilapia is to change the osmotic pressure of plasma through changing the activity of Na＋-K＋-ATPase. Through crossbreeding we got a new hybrid between Oreochromis niloticus and Sarotherodon melanotheron. The hybrid grows faster than the male parent and shows a stronger osmoregulation ability than the female parent. In order to explore the molecular mechanism of salinity tolerance of tilapia, learn and screen the related genes about salinity tolerance, through RT-PCR we cloned and analyzed the cDNAs encoding prolactin from O. niloticus characterized by fast growth but low salinity tolerance,from S. melanotheron characterized by high salinity tolerance but slow growth and from their hybrid characterized by ideal growth and salinity tolerance. First,we used the Trizol methods to extracted total RNA,then reverse translate the mRNA to cDNA. Through Polymerase Chain Reaction（PCR） the sequence of PRLI was amplificated. Then the sequence was cloned to Escherichia coli and sequenced. And the PRLI nucleotide and amino acid sequence were analyzed. Major results are as follows：（ 1）The sequence cloning and Clustal X1.83 analysis showed that PRL of three genotypes of tilapia consists of 339 bp and encodes a putative protein of 112 amino acids.（ 2）There was 97.94%-99.71% identity in nucleotide sequence,over 99.11% identity in amino acid sequence among three genotypes of tilapia, indicating high conservation of PRLI gene in tilapias.（ 3）In hybrid vs O. niloticus, there were five varieties in nucleotide with 1.47% in proportion; In hybrid vs S. melanotheron,there were one variety,with 0.3% in proportion.（ 4） On the amino acid sequence the 80th point in O. niloticus was proline residue（Pro）,but in S. melanotheron and hybrid it was serine residue（Ser）.（ 5）Phylogenetic tree of MEGA4 showed that the hybrid and S. melanotheron were clustered into one group. Results（ 3）,（4）and�

关 键 词：罗非鱼 催乳素PRL RT-PCR 克隆 耐盐性 

分 类 号：S917[农业科学—水产科学]