莫桑比克罗非鱼ghrelin受体基因的特性及ghrelin受体和ghrelin mRNA组织表达  

Characterization of Ghrelin Receptor (GHSR) Gene and Tissue Expression of Ghrelin mRNA and GHSR of Oreochromis mossambicus

作　　者：高风英[1] 王欢[1,2] 叶星[1] 卢迈新[1] 黄樟翰[1] 朱华平[1] 杨丽萍[1] 

机构地区：[1]中国水产科学研究院珠江水产研究所,广东广州510380 [2]广东海洋大学水产学院,广东湛江524025

出　　处：《安徽农业科学》2010年第5期2274-2280,共7页Journal of Anhui Agricultural Sciences

基　　金：国家科技支撑计划(2006BAD01A1201);广东省农业重点项目(2008A020100006;2009B0201003);现代农业产业技术体系建设专项资金(nycytx-48-4);公益性行业(农业)科研专项(3-49);广东省海洋渔业科技推广专项(A200899B02);广东省重大科技兴渔项目(B200701A06)

摘　　要：[目的]了解莫桑比克罗非鱼ghrelin/GHSR系统的生理功能。[方法]采用RT-PCR和RACE技术分离莫桑比克罗非鱼2个GH-SR全长cDNA序列,并用荧光定量PCR方法检测了莫桑比克罗非鱼ghrelin基因及其受体GHSR-1a mRNA水平的组织表达,以及饥饿对这2个基因表达的影响。[结果]获得了莫桑比克罗非鱼2个GHSR cDNA全序列(GHSR-1a、GHSR-1b)。GHSR-1a序列全长1 627bp,编码384个氨基酸,具有7个跨膜结构域结构;GHSR-1b序列全长1 858 bp,编码298个氨基酸,只具有前5个TM,在第6个TM的第4个氨基酸处开始缺失。正常生理条件下,2基因在所检测组织中均有表达,但存在明显的组织差异。ghrelin主要由胃中分泌,除性腺外,雌鱼所有被检测组织的表达量均高于雄鱼的表达量,以肌肉中ghrelin基因的表达差异最大,雌鱼是雄鱼的30.4倍。莫桑比克罗非鱼GHSR-1a基因在垂体、肝脏、心脏中表达量较高,且被检测组织中雄鱼的表达量均高于雌鱼的表达量,其中鳃组织的表达差异最大,雄鱼是雌鱼的36.3倍。饥饿28 d后莫桑比克罗非鱼胃中ghrelin基因表达增加,雄鱼ghrelin基因分泌量增加了3.7倍,雌鱼增加了2.6倍;雌雄个体垂体中GHSR-1a的分泌量均略有下降。[结论]ghrelin/GHSR-1a系统可能具有调节莫桑比克罗非鱼能量平衡的作用。[Objective] The research aimed to understand the physiological function of ghrelin/GHSR system.[Method] The full length of cDNA encoding GHSR-1a and GHSR-1b were cloned with RT-PCR and RACE,the tissue expression of ghrelin and GHSR-1a mRNA under normal feeding condition as well as fasting state were detected using fluorescence quantitative PCR.[Result]The GHSR-1a was 1 627 bp in length,which encoded 384 amino acid residues,including seven transmembrane domains（TM）.The GHSR-1b was 1 858 bp in length,which encoded 298 amino acid residues,including five TM.Under normal physiological conditions,both ghrelin and GHSR-1a mRNA could be detected in all tissues examined,but expression level varied among different tissue.The highest ghrelin mRNA levels were found in stomachs of both male and female individuals.The ghrelin mRNA levels in female were higher than those in male individuals in all tissues tested except gonad.The greatest difference was found in muscle,in which ghrelin mRNA level in female individuals was 30.4 fold of that in male individuals.High levels of GHSR-1a mRNA were detected in pituitary,liver and heart.GHSR-1a mRNA levels in male individuals were higher than female individuals in all tissues tested.After four weeks starvation,the gastric ghrelin mRNA levels increased.It increased 3.65 folds in males and 2.63 fold in females.While the GHSR-1a mRNA levels in pituitary was decreased slightly in male and female individuals.[Conclusion] The results indicated that ghrelin/GHSR system regulated energy balance of Oreochromis mossambicus.

关 键 词：莫桑比克罗非鱼 GHSR 组织表达 

分 类 号：S965.125[农业科学—水产养殖]