猪Dlx5基因多态性及其与猪体尺和胸椎数的关系

Polymorphisms of Distal-less Homeobox 5(Dlx5) Gene in Pigs and Its Association with Body Sizes and Thoracic Spine Numbers

为探讨猪远端缺失基因5(distal-less homeobox 5,Dlx5)的多态性、群体分布特性及其与体尺和胸椎数的关系,采用PCR-RFLP方法检测了猪Dlx5基因g.394C>T位点在6个中外猪品种中的多态性分布,并分析了该位点与猪体尺和胸椎数的关系。检测结果表明,经HhaⅠ酶切后在6个猪品种群体均发现了CC、CT和TT 3种基因型,其中C等位基因在莱芜黑猪中为优势等位基因,而T等位基因在里岔黑猪、鲁莱黑猪、杜洛克猪、大约克猪和长白猪中占优势。在该多态性位点,莱芜黑猪、里岔黑猪、鲁莱黑猪、杜洛克和长白猪群体均处于哈代—温伯格平衡(P>0.05),而大约克猪群体偏离平衡状态(P<0.05);基因型在群体间的分布差异极显著(P<0.01)。群体遗传特性分析表明,有效等位基因数在1.254～1.991之间;杜洛克猪的多态信息含量为0.182,属于低度多态,其余品种均在0.254～0.374之间,属于中度多态。关联分析结果表明,该多态性位点对莱芜黑猪体长、体高、屠前活重、腹围、胸围、腿臀围和胸椎数以及里岔黑猪胸椎数的影响均不显著(P>0.05)。Dlx5基因g.394C>T位点在猪群中存在多态,基因型分布在莱芜黑猪与其他猪种间不同,与猪体尺和胸椎数无显著关联。

This study was conducted to investigate the polymorphism,genetic distribution of distal-less homeobox 5 gene（Dlx5） in pigs and its associations with body sizes and thoracic spine numbers.The polymorphism distribution of g.394CT loci.in Dlx5 gene of 6 breeds of pigs were detected by PCR-RFLP and the relationship between the Dlx5 genotypes and body sizes and thoracic spine numbers were analyzed.The results showed that there were three genotypes such as CC,TC and TT in the 6 pig populations found by enzyme digestion of HhaⅠ.Allele C was dominant in Laiwu black pigs,and allele T was dominant in Licha black pigs,Lulai pigs,Duroc pigs,Yorkshire pigs and Landrace pigs,respectively.A chisquare analysis showed that the genotype distribution in this polymorphism loci.in Laiwu black pigs,Licha black pigs,Lulai Black pigs,Duroc pigs and Landrace pigs populations were in Hardy-Weinberg equilibrium（P0.05）,whereas was not in Yorkshire pigs（P0.05）.The distribution of CC,TC and TT genotypes was significantly different（P0.01） among six populations.Population genetics analysis showed that effective number of alleles were ranged from 1.254 to 1.991.The polymorphism information content（PIC）in Duroc pigs was 0.182 which was in low polymorphic,while it was ranged from 0.254～ 0.374 in other pigs which was in moderate polymorphic.The association analysis showed that the Dlx5 g.394CT mutation was not significantly associated with body length,height at withers,live weight,abdominal circumference,chest circumference,hip circumference and numbers of thoracic spine of Laiwu black pigs and numbers of thoracic spine of Licha black pigs（P0.05）.It indicated that there the g.394CT loci in Dlx5 gene were polymorphism in the six pig populations and the genotype distribution in Laiwu black pigs were different with other breeds.And no significant association was detected between the loci.and body sizes and thoracic spine numbers in pigs.