鸡脂肪性状重要候选基因的连锁不平衡模式分析  

Linkage Disequilibrium Patterns of Polymorphisms in Candidate Genes for Fatness in Chickens

作　　者：李晓存[1] 户国[1] 王守志[1] 李辉[1] 

机构地区：[1]东北农业大学动物科学技术学院,哈尔滨150030

出　　处：《农业生物技术学报》2011年第2期278-286,共9页Journal of Agricultural Biotechnology

基　　金：国家高技术研究发展计划(863)项目(No.2006AA10A120);国家重点基础研究发展规划(973)项目(No.2006CB102105);现代农业产业技术体系建设专项(No.nycytx-42)共同资助

摘　　要：对鸡脂肪性状候选基因进行连锁不平衡(linkage disequilibrium,LD)分析可以为理解鸡体脂沉积的遗传学机制提供重要信息,并且可以提高脂肪性状相关分子遗传标记的检出效率。本研究以东北农业大学肉鸡高、低脂双向选择品系第8世代肉仔鸡为实验材料,通过直接测序、高效液相色谱(DHPLC)、单链构象多态性(PCR-SSCP)、限制性片段长度多态性(PCR-RFLP)、长度多态性(PCR-LP)等方法对过氧化物酶增殖体激活受体(PPAR-γ)、载脂蛋白B(ApoB)、解耦联蛋白(UCP)以及其他10个鸡脂肪性状重要候选基因进行多态性检测,计算候选基因标记间LD参数|D'|与r2,分析这些候选基因标记间的LD模式并探讨其规律。初步发现了以下特征:1、在各候选基因内,标记间的|D'|与r2值并不匹配,取值区间差异很大,|D'|值普遍大于r2;另外,在有些基因内的相同标记间,|D'|、r2值相差很大,甚至在|D'|=1时,r2接近于0。2、在不同基因甚至在同一基因内不同区域LD水平差异很大且物理距离与LD关系并不成线性关系。3、在有些基因内,如ApoB基因,相间位点间的|D'|和r2值大于相邻位点间的值。4、有些基因,如PPAR-γ,相同标记间LD水平在高、低脂系间存在很大差异。本研究结果提示,在群体遗传学研究中进行候选基因LD分析时,LD参数r2的应用价值比|D'|更大。Investigating patterns of linkage disequilibrium（LD） is helpful for a more in-depth understanding of the genome-wide mechanisms for the genetic variation response to the natural and artificial selection in model and domestic animals.LD analysis for the candidate genes on fatness in chickens can provide more important information about the genetic control of fat deposition and make the molecular markers associated with fatness more powerful.In this study,polymorphisms of perpxisome proliferator-activated receptor-γ（PPARγ）,apolipoprotein B（ApoB）,uncoupling protein（UCP） and other 10 candidate genes on chicken fatness among individuals were detected by DNA sequencing,denaturing high performance liquid chromatography（DHPLC）,single-strand conformation polymorphism（SSCP）,restriction fragment length polymorphism（RFLP） and labelled primers（LP） methods.LD investigation among the polymorphisms of the candidate genes was performed in the 8th generation populations of the Northeast Agricultural University broiler lines divergently selected for abdominal fat content,two common measures of LD,｜D＇｜ and r2,were used in this study.The results showed that the value of ｜D＇｜ and r2 often did not match very much within the candidate genes.The value of ｜D＇｜ usually was larger than value of r2,sometimes even ｜D＇｜=1,while r2 was close to zero.Furthermore,in different genes,even within the same gene,LD patterns of different regions were usually different,and there was no a linear correlation between physical distance and the value of ｜D＇｜ or r2.In addition,in some genes,such as ApoB,the values of ｜D＇｜ and r2 between nonadjacent polymorphisms were much larger than those between the adjacent polymorphisms.Finally,there were different LD patterns of polymorphisms in some genes,such as PPAR-γ between lean and fat chicken lines.The results in this study also suggested,as a LD measure parameter,r2 is more useful than ｜D＇｜in population genetics analysis.

关 键 词：鸡 脂肪性状 候选基因 连锁不平衡模式 |D'| r2 

分 类 号：S828.2[农业科学—畜牧学]