异源四倍体鲫鲤及亲本ApoE的克隆及组织表达分析

载脂蛋白E(Apolipoprotein E,ApoE)作为胆固醇代谢过程中的关键因子,参与脂蛋白转运和性腺发育。为进一步了解该基因的作用,本实验克隆并测序了异源四倍体鲫鲤及其父母本ApoE基因的全长序列。异源四倍体鲫鲤、红鲫和鲤的ApoE全长分别为1393 bp、1384 bp和1396 bp,均编码281个氨基酸。序列对比表明,异源四倍体鲫鲤ApoE与父本鲤更为相似。另外有2个氨基酸位点发生了与父母本均不同的变异,证明异源四倍体鲫鲤除了有杂交特征外也产生了变异。通过Mega软件构建的哺乳动物ApoE进化树与系统分类相一致:鲤科鱼类的ApoE聚类在一起而分离于其它物种。Real time PCR分析表明,ApoE基因在3种鱼中的组织表达模式基本一致,所有组织均有表达,而在脾脏中表达最高。

Apolipoprotein E gene cloning and tissues expression analysis in allotetraploid and its parents

As a key factor in cholesterol metabolism,Apolipoprotein E is participate in lipoprotein transport and gonadal development.To understand function of ApoE,the cDNAs of allotetraploid and their parents-red crucian carp and common carp were cloned and sequenced.The full length of allotetraploid,red crucian carp and common carp ApoE cDNAs were 1393 bp,1384 bp and 1396 bp,respectively.All the cDNAs encode 281 amino acids.Based on alignment result,ApoE of allotetraploid is more similar with common carp than red crucian carp.Meanwhile,besides characters inherited from parents,allotetraploid shows specific mutation in ApoE.By constructing phylogenetic tree using Mega software,the phylogenetic tree of ApoE was consistent with taxonomy: cyprinid fish are clustered together rather than other vertebrates.Realtime-PCR analysis indicated that the expression patterns of ApoE in allotetraploid,common carp and red crucian carp are similar.All the tissues had ApoE expression.The highest expression was in spleen.This research gave information in gene variation in the process of allotetraploid evolvement and lipid me-tabolic mechanism of fish.