奥尼罗非鱼GHR2基因序列及其表达特征分析  

The sequence and expression characteristic of GHR2 gene in Oreochromis niloticus(♀)× O. aureus(♂)

作　　者：钟欢 张孝瑾 肖俊 唐瞻杨 郭忠宝 罗永巨 周毅[1] ZHONG Huan;ZHANG Xiao-jin;XIAO Jun;TANG Zhan-yang;GUO Zhong-bao;GUO Zhong-bao;ZHOU Yi(Tilapia Genetic Breeding Center,Guangxi Academy of Fishery Sciences,Nanning 530021,China;College of Fisheries&Life,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]广西水产科学研究院罗非鱼遗传育种中心,南宁530021 [2]上海海洋大学水产与生命学院,上海201306

出　　处：《南方农业学报》2018年第11期2292-2297,共6页Journal of Southern Agriculture

基　　金：国家自然科学基金项目(31460688;31760756);国家现代农业(特色淡水鱼)产业技术体系建设项目(CARS-46);广西直属公益性科研院所基本科研业务费专项项目(GXIF-2014-13)

摘　　要：【目的】深入了解生长激素受体2(GHR2)基因在奥尼杂交罗非鱼及其亲本(尼罗罗非鱼和奥利亚罗非鱼)中的表达差异,为研究杂交过程中GHR基因的结构及功能变化提供依据,也为鱼类杂交育种提供理论支撑。【方法】利用SOAPdenovo从奥尼罗非鱼肝脏转录组数据中提取GHR2基因序列,采用BioEdit 7.0.5.3比对奥尼罗非鱼及其亲本的GHR2氨基酸序列差异,以MEGA 4.1进行系统进化分析及构建系统发育进化树,并利用实时定量PCR分析GHR2基因在奥尼罗非鱼不同组织中的表达情况及其在奥尼罗非鱼和亲本中的表达差异。【结果】拼接获得的奥尼罗非鱼GHR2基因开放阅读框为1722 bp,共编码574个氨基酸,相对分子量为64.18 kD,理论等电点为4.86;奥尼罗非鱼GHR2氨基酸序列包含一个保守的信号肽和一段跨膜区。基于GHR2氨基酸序列构建的系统发育进化树显示,奥尼罗非鱼与尼罗罗非鱼和奥利亚罗非鱼存在高度相近的亲缘关系,尤其与母本(尼罗罗非鱼)的亲缘关系最近。GHR2基因在奥尼罗非鱼不同组织中均有表达,以在肝脏中的表达量最高,显著高于除肌肉外的其他组织(P<0.05),其次是肌肉、卵巢、心脏和垂体,在头肾中的表达最低。GHR2基因在奥尼罗非鱼肝脏和肌肉中的表达量明显高于其双亲(尼罗罗非鱼和奥利亚罗非鱼)的表达量。【结论】GHR2基因属于广泛表达基因,在奥尼罗非鱼、尼罗罗非鱼和奥利亚罗非鱼中高度保守;GHR2基因在奥尼罗非鱼中的表达优势与其快速生长的杂种优势有关。【Objective】The present study aimed to understand the expression differentiation of growth hormone receptor 2(GHR2)gene in Oreochromis niloticus(♀)×O.aureus(♂)and its parents.This study provided evidence for GHR gene structural and functional changes in hybridization process and supplied theoretical support for cross breeding in fish.【Method】Using SOAPdenovo software,the GHR2 gene sequence of O.niloticus(♀)×O.aureus(♂)was extracted from liver transcriptome.The alignment analysis between O.niloticus(♀)×O.aureus(♂)and its parents was performed by BioEdit 7.0.5.3 software.MEGA 4.1 package was used to conduct phylogenetic analysis and construct the phylogenetic tree.Realtime quantitative PCR was employed to investigate the GHR2 gene expression in different tissues from O.niloticus(♀)×O.aureus(♂)and the differential expression between O.niloticus(♀)×O.aureus(♂)and its parents.【Result】The assembled gene GHR2 from O.niloticus(♀)×O.aureus(♂)contained a 1722 bp open reading frame,encoded 574 amino acids.The relative molecular mass was 64.18 kD and the theoretical isoelectric point was 4.86.A conserved signal peptide and a transmembrane region were found in GHR2 amino acid sequence in O.niloticus(♀)×O.aureus(♂).The constructed phylogenetic tree based on GHR2 amino acid sequence revealed high similarity among O.niloticus(♀)×O.aureus(♂),Nile tilapia and Blue tilapia,especially between O.niloticus(♀)×O.aureus(♂)and its maternal(Nile tilapia).GHR2 gene expressions were found in all the tested tissues in Nile tilapia.The highest expression was found in liver,which was significantly higher than other tissues except muscle(P<0.05).The GHR2 expressions were moderate in muscle,ovary,heart and pituitary.The expression in head-kidney was the lowest.The expressions of GHR2 in liver and muscle were significantly higher than those in its parents(Nile tilapia and blue tilapia).【Conclusion】Gene GHR2 is a widespread expression gene and is highly conserved in O.niloticus(♀)×O.au

关 键 词：奥尼罗非鱼 生长激素受体2(GHR2) 亲缘关系 表达差异 非加性表达模式 

分 类 号：S965.125[农业科学—水产养殖]