Four jlGHRs (jlGHR1a, jlGHR1b; jlGHR2a, jlGHR2b) were cloned by using PCR, RT-PCR and RACE methods in Cyprinus carpio var.jian.Homology analysis and phylogenetic tree showed that jlGHR1a,-1b and jLGHR2a,-2b belonged to fish GHR1 and GHR2, respectively.The differences of amino acid sequence were 5％ and 11％ between the two paralogs, but the functional conversation regions, such as extracellular motif FGVFS, Box1 and Box2 were mostly identical.The difference between jlGHR1s with jlGHR2s amino acid sequence was 41％.jlGHRs had the same genetic structure as zebrafish.There were 7 introns in the open reading frame.The lengths of specific introns between paralogs were obvious different.The comparability between jlGHRl, jlGHR2 and other GHR1, GHR2 was consisted with traditional staple.In this study, differentjlGHR transcripts were found in the liver of Cyprinus carpio var.jian, including jlGHR 1b' (lost exon 4), jlGHR2a' (containing intron 3) and jlGHR 2as (lost partial exon 8).Real time-PCR results indicated that despite quite different quantity, 4 genes expressed in all the 8 tissues, such as brain, liver,heart, head kidney, kidney, intestines, spleen and muscle.Expression levels of 4 jlGHRs were the highest in muscle.Except brain, jlGHR2b expression was higher than other 3 genes in tissues.It was conferred that jlGHR2a was under lower selection stress thanjlGHR 2b from the several transcripts and lower expression.The two paralogs jlGHR1s and -2s isolated from C.carpio approved that two sets of gene existed in Cyprinus carpio var.jian, which indicated that C.carpio var.jian was good material for homeotic genes differentiation researching.The two sets of gene existed in Cyprinus carpio var.jian also laid foundation for finding SNP loci in the GHR correctly.%使用PCR、RT-PCR和RACE方法分离克隆了建鲤基因组内的4个jlGHRs基因,同源性分析和系统树表明它们两两分属于鱼类GHR1和GHR2,命名为jlGHR1a、jlGHR1b;jlGHR2a、jlGHR2b.jlGHR1s和jlGHR2s的两个旁系同源基因间氨基酸差异分别为5%和11%,但功能保守区FGVFS基序、Box1、Box2基本一致,jlGHR1s和jlGHR2s氨基酸差异为41%.jlGHRs和斑马鱼GHRs基因结构相同,在阅读框内存在7个内含子,两旁系同源基因间内含子长度或序列存在差异.jlGHR1s、jlGHR2s与不同鱼类GHR1、GHR2同源性高低与传统分类地位一致.实验过程中发现建鲤肝脏存在jlGHRs的多种转录子,包括丢失了外显子4的jlGHR1b'、保留了内含子3的jlGHR2a'、丢失了部分外显子8的jlGHR2as.实时定量RT-PCR组织表达结果显示4个jlGHRs在脑、肝、心、头肾、肾、肠、脾、肌肉各组织中均有表达,但表达量差异明显,其中肌肉组织中4个基因表达量均最高,脑中4个基因的表达水平相当,其余各组织中jlGHR2b的表达量均最高.从多转录子和较低表达量推测jlGHR2a所受的选择压力低于jlGHR2b.鲤鱼基因组内分离到GHR1、GHR2的两个旁系同源基因在功能基因方面证实了鲤鱼体内存在两套基因,表明鲤鱼是研究同源基因变异分化的好材料,也为今后正确查找jlGHRs基因上的SNP位点奠定了基础.
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