草鱼JAK2基因片段序列的克隆及其组织表达分析

通过实时荧光定量PCR(RT-PCR)法从草鱼肝脏中首次克隆获得草鱼JAK2基因的片段序列。该片段序列长671 bp,编码223个氨基酸,氨基酸序列分析表明草鱼JAK2基因片段与其他物种的相似性在70%～91%之间;系统进化树显示,鱼类的JAK2独立聚成一支,草鱼与斑马鱼聚成一支,与鳜鱼和墨绿凹鼻鲀聚成的一支再聚成一支。实时荧光定量PCR分析表明,草鱼JAK2基因在肝脏、肌肉、脑、心脏、脾脏和肠系膜脂肪组织中均有表达,其中在肝脏组织中表达量最高,显著高于其他组织(P<0.05),其次是肌肉、脑、脾脏和肠系膜脂肪组织,在心脏组织中表达量最低,且显著低于其他组织(P<0.05)。本研究为进一步研究草鱼JAK2基因的结构和功能奠定了基础。研究亮点:JAK2基因在鱼类上的研究报道甚少。本研究首次克隆了草鱼JAK2基因片段序列;且发现JAK2基因在肝脏组织中表达量最高,心脏组织中表达量最低,为草鱼JAK2基因的结构及其信号转导等生理功能的深入研究奠定了基础。

Cloning and tissue expression of JAK2 gene in grass carp (Ctenopharyngodon idella)

The JAK2(Janus kinase 2) gene fragment sequence was cloned from liver of grass carp(Ctenopharyngodon idella) by RT-PCR.The obtained cDNA fragment sequence was 671 bp,which encoded 223 amino acids.The amino acid sequence comparison results showed that the JAK2 amino acid of grass carp shared 70%-91% identity with other species.Phylogenetic tree of JAK2 generated by Neighbor Joining method suggested that all teleosts cluster together,and the grass carp JAK2 is clustered closely with that of zebrafish,mandarin fish and globefish.Then the expressions of different tissues including liver,muscle,brain,heart,spleen and mesentery fat tissue were analyzed by real-time fluorescence quantitative PCR.The results showed that the JAK2 gene of grass carp expressed in all tissues and highest in liver(P<0.05),lower in muscle,brain,spleen and fat tissue,lowest in heart(P<0.05).This study will be helpful for further understanding the structure and function of JAK2 in C.idella.