驯化和品种培育形成了体长性状各异的猪品种。猪体长是多基因控制的复杂性状，与产肉量具有明显正相关，是猪种改良的重要经济性状之一。申请人前期完成了杜洛克猪体长性状全基因组关联分析，鉴定了染色体1、7、8、13和14上与体长性状显著相关的基因组区段。本项目拟在前期基础上，综合群体组学信息进一步在上述区段精细定位猪体长性状重要基因及SNPs。实验拟选取我国特有小体型海南五指山猪，另以当地海南野猪和商用大体型杜洛克猪为对照，通过RNA-seq对上述猪种进行深度表达谱分析，揭示其转录组差异；同时结合体长差异群体selective sweep分析结果，缩小体长性状相关基因组区段；进一步综合特征群体重测序单倍型数据，从群体基因组和转录组水平精细定位猪体长性状重要基因及SNPs，并进行不同猪种候选基因及SNPs分子遗传特性和进化分析。研究结果将为体长性状变异的分子机制解析及猪体长性状的分子选育提供科学依据。

Pig breeds with varied body length were formed during domestication and breed development. The body length is a polygenic complex trait, which is close positive association with the carcass weight and it is one of important target traits in pig breeding. Our preliminary GWAS results suggested that some SNPs on Chromosome 1, 7, 8, 13 and 14 were associated with porcine body length. This study will aim to investigate the important gene and SNPs for body length based on the genome and transcriptome data. Chinese specific miniature pig breed- - -Wuzhishan pig, Chinese Hainan wild boar and commercial Duroc pig breed will be analyzed in our current study. Our strategy is to investigate the expression pattern difference of body length related genes among above mentioned pigs by RNA-seq, at the same time the results from selective sweep among different pig breeds will be combined for narrowing down the potential body length-related genomic regions, which will be re-sequenced for fine mapping of important gene and SNPs related to porcine body length; Finally we will study the molecular genetic character and evolution analysis of identified body length-related gene and SNPs. Above results will help to reveal the molecular mechanism of body length evolution and provide molecular markers for improvement of body length trait in pigs.