长白猪prepro-orexin基因多态性及其与采食和生长性状的关联分析

为揭示食欲素前体（prepro-orexin）基因对长白猪采食和生长性状的影响，试验采用PCR产物直接测序法对132头长白猪prepro-orexin基因的C62T和G426A位点多态性进行检测，并对各位点与30~100 kg阶段的采食及生长性状进行关联分析。结果表明，长白猪prepro-orexin基因C62T和G426A位点均处于Hardy-Weinberg平衡状态，等位基因频率表现为野生型（C、G）高于突变型（T、A）；两个位点的4种单倍型和7种单倍型组合中，CG、TA为主要单倍型，CG/CG、TA/CG和TA/TA为主要单倍型组合。C62T位点的CC基因型、G426A位点的GG基因型及CG/CG单倍型组合均可显著减少日采食次数、延长每次采食时间和提高每次采食量（P < 0.05）；其中CG/CG组合的日采食次数、每次采食时间、每次采食量分别较TA/CG组合显著减少1.22次、延长0.79 min和提高32.18 g（P < 0.05），而与TA/TA组合的差异未达到显著水平（P > 0.05）。C62T位点的TT基因型、G426A位点的AA基因型及TA/TA单倍型组合可显著或极显著缩短达100 kg体重日龄、提高30~100 kg平均日增重（P < 0.05；P < 0.01）；TA/TA组合达100 kg体重日龄分别较CG/CG、TA/CG组合分别显著缩短6.23和6.69 d（P < 0.05），平均日增重分别极显著提高47.91和50.04 g/d（P < 0.01）。结果表明，prepro-orexin基因C62T和G426A位点对长白猪采食和生长性状的影响具有明显的协同效应。

Polymorphism of prepro-orexin Gene and Its Association Analysis with Feeding and Growth Traits in Landrace Pigs

In order to investigate the effects of prepro-orexin gene on feeding and growth traits of Landrace pigs,the polymorphisms of C62T and G426A sites of prepro-orexin gene in 132 Landrace pigs were detected using PCR product direct sequencing,the association of the two sites with feeding and growth traits during 30 to 100 kg body weight were analyzed.The results showed that the two sites of prepro-orexin gene were in Hardy-Weinberg equilibrium in Landrace pigs,and the frequency of wild-type alleles C and G were higher than those of mutant-type alleles T and A;In the four haplotypes and seven haplotype combinations,CG,TA haplotypes and the combinations CG/CG,TA/CG,TA/TA were the dominant types.The CC genotype of C62T,GG genotype of G426A and haplotype combination CG/CG could significantly decrease the number of visits per day (NVD),prolong the time spent on eating per visit (TPV) and increase the feed intake per visit (FIV)(P < 0.05),which the NVD,TPV and FIV of combination CG/CG were 1.22 times fewer,0.79 min longer and 32.18 g greater than those of combination TA/CG (P < 0.05),but there were no significant difference from combination TA/TA (P > 0.05).The TT genotype of C62T,AA genotype of G426A and haplotype combination TA/TA could significantly or extremely significantly shorten the days to 100 kg body weight (D100) and increase the average daily gain (ADG) (P < 0.05 or P < 0.01),which the D100 and ADG of the combination TA/TA were 6.23 d and 47.91 g/d shorter than those of combination CG/CG (P < 0.05;P < 0.01),6.69 d and 50.04 g/d higher than those of combination TA/CG (P < 0.05;P < 0.01).In Landrace pigs,the influences of C62T and G426A sites of prepro-orexin gene on the feeding and growth traits had obvious synergistic effects.