罗非鱼MC4R基因克隆及与其生长相关的SNPs位点  

Cloning of MC4R gene and study on the association between SNPs of MC4R and growth trait in tilapia (Oreochromis niloticus)

作　　者：刘福平[1,2] 白俊杰[1] 叶星[1] 李胜杰[1] 李小慧[1] 于凌云[1] 

机构地区：[1]中国水产科学研究院珠江水产研究所中国水产科学研究院热带亚热带鱼类选育与养殖重点开放实验室,广东广州510380 [2]上海海洋大学水产与生命学院,上海201306

出　　处：《中国水产科学》2009年第6期816-823,共8页Journal of Fishery Sciences of China

基　　金：农业部"948"项目(2006-G55);国家"十一五"科技支撑计划项目(2006BAD01A1201);国家科技基础条件平台工作项目(2005DKA21103)

摘　　要：黑素皮质素受体-4(Melanocortin receptor-4,MC4R)是5种已发现的黑素皮质素受体家族成员之一,属于跨膜G-蛋白耦联受体超级家族,对于调节动物的采食量、体质量及能量稳态有着重要的作用。本研究采用基因组步移技术获得了尼罗罗非鱼(Oreochromis niloticus)MC4R基因组DNA序列。该基因全长2547bp,其中5′侧翼序列长为1481bp,3′侧翼序列长为82bp,编码区序列长为984bp,只有1个外显子。采用PCR产物直接测序法、PCR-RFLP和CRS-PCR技术对尼罗罗非鱼MC4R基因启动子和外显子区域进行了SNPs位点的检测和分型,结果共检测到5个SNPs位点(-G1000C、-T974A、C276T、C561T和C708T),其中外显子上的3个SNPs位点均为同义突变。利用一般线性模型分析5个SNPs位点与尼罗罗非鱼生长性状的关系,结果表明,5个SNPs位点不同基因型之间体质量均值差异最大值分别为9.5%、23.2%、14.4%、18.6%和13.5%,没有达到显著水平(P>0.05)。将5个SNPs位点不同基因型组合成7种双倍型(去掉频率小于3%的组合),关联分析表明,在体质量和体长这2个主要生长性状方面,双倍型D4与D1、D3、D6存在显著性差异(P<0.05),双倍型D2与D3、D6也存在显著性差异(P<0.05)。因而可以考虑将MC4R基因作为影响罗非鱼体质量等生长性状的候选基因,应用于罗非鱼分子标记辅助育种。Melanocortin receptor-4（MC4R）is one of members of the family of melanocortin receptors（MCR）and belongs to the family of seven transmembrane G-protein coupled receptors.It can affect food intake,body weight and energy homeostasis.In this research,the genomic sequence of Tilapia MC4R is amplified from DNA isolated by using GenomeWalker technique.The sequence analysis results showed that the full-lengh of MC4R gene is 2 547 bp with an open reading frame（ORF）of 984 bp.Five SNPs sites in promoter and exon were identified from MC4R gene by using sequencing（-G1 000C,-T974A,C276T,C561T and C708T）.The polymorphisms were genotyped by PCR-RFLP and CRS-PCR.A general linear model was used to statistically analyze associations of MC4R gene polymorphisms with growth traits.The most difference of mean body weight among 5 different genotype were 9.5%,23.2%,14.4%,18.6%and 13.5%,but the difference was not significantly different（P〉0.05）.Seven diplotype,with the minor allelic frequencies of above 3%,were constructed based on five SNPs in the experiment population.Association analysis indicated that there was significant association between diplotype and body weight and body length（P〈0.05）.By multiple comparisons,we found that the mean of body weight or body length for diplotype D4 showed significant association with D1,D3 and D6,D2 also showed significant association with D3 and D6（P〈0.05）.MC4R gene could be a candidate modifier gene for tilapia growth traits which would be useful for tilapia molecular breeding.

关 键 词：尼罗罗非鱼 MC4R SNPS 双倍型 关联分析 

分 类 号：Q959[生物学—动物学]