摘要
旨在检测"马脸"型和"狮子头"型玉山黑猪在基因组上的遗传分化信号,结合全基因组关联分析(GWAS),鉴别影响玉山黑猪两种头型的候选基因并探寻其可能的形成机理。本研究选取玉山黑猪国家保种场的24头"马脸"型个体和12头"狮子头"型个体,利用Illumina猪60KSNP芯片对这些个体进行扫描和基因分型。基于60K SNP芯片数据,检测"马脸"型和"狮子头"型两个类群间的遗传分化系数(Fst)。同时,进行病例-对照的GWAS分析和连锁不平衡(LD)分析,根据Fst、GWAS和LD分析结果确定重要候选基因。结果表明,两个群体间最强的遗传分化信号位于猪10号染色体,GWAS同样在该区域检测到显著的关联位点。LD及单倍型分析将置信区间锁定在该染色体11.76~12.05 Mb的一段290kb的区域。本研究基于猪60K芯片数据,通过遗传分化分析、全基因组关联分析和连锁不平衡分析等手段,初步推测RAB3GAP2和IASR2为影响玉山黑猪头型的候选基因,该结果为进一步解析中国地方猪不同头型的形成机制奠定了基础。
The aim of this study was to identify candidate genes affecting the two head types(longpointed head and short head)in Yushan Black pigs through conducting agenome-wide association study(GWAS)and a genome-wide scan for the selection signatures.Twenty-four pigs with longpointed head and 12 pigs with short head were selected from the national conservation farm of Yushan Black pigs and were genotyped using Porcine SNP 60 KBeadChips.The Fst value of each SNP was calculated to detect signatures of genetic differentiation between the two groups of pigs.Meanwhile,case-control GWAS and linkage disequilibrium(LD)analysis were performed to define confidence intervals and candidate genes based on Fst.The results showed that the most significant signature of genetic differentiation was located on Sus Scrofachromosome(SSC)10,and a genome-wide significant locus within the same region was also detected by GWAS.The most likely interval of this locus was defined by the LD block analysis,about 290 kb(from 11.76 to 12.05 Mb)on SSC10.By applying genetic differentiation analysis,genome-wide association study and linkage disequilibrium(LD)analysis,we speculated that candidate genes for head types were RAB3 GAP2 and IASR2 in Yushan Black pigs.The findings will contribute to reveal the genetic basis of phenotypic changes in head types in Chinese indigenous pigs.
引文
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