长毛兔Hoxa4基因多态性及其与产毛量关联性分析

Polymorphism of Hoxa4 Gene and Its Influence on Performance Traits in Cangxi Angora Rabbits

【目的】分析苍溪长毛兔Hoxa4基因第2外显子遗传多态性及其与产毛量的相关性,发现与产毛量相关的分子标记,为加快毛兔选育提供参考。【方法】采用PCR产物直接测序法对208只苍溪长毛兔Hoxa4基因第2外显子进行遗传变异检测,并运用SAS 8.1软件对苍溪长毛兔Hoxa4基因遗传变异与产毛量进行关联性分析。【结果】苍溪长毛兔Hoxa4基因第2外显子存在1个SNP位点(c.294T>C),该突变导致氨基酸由Ser-Pro(TCC-CCC)转变,共检测到TT、TC、CC三种基因型。其中TC基因型为优势基因(0.596 2),T为优势等位基因(0.562 9)。对突变位点的群体遗传参数分析发现:杂合度为0.494 4,有效等位基因数为1.977 9,多态信息含量(0.372 2)处于中度多态,说明Hoxa4基因在苍溪长毛兔中具有较高遗传变异能力,有持续选育的潜力实现兔群遗传改良。关联性分析发现携带CC基因型的个体73日龄产毛量显著高于TC型(P<0.05),且146日龄阶段产毛量显著高于TT型(P<0.05),极显著高于TC型(P<0.01)。【结论】Hoxa4基因第2外显子突变可作为评定苍溪长毛兔产毛量的遗传标记。

[Objective] This study was to investigate the polymorphisms of homeobox A4 （Itoxa4）gene and its association with economic traits in Cangxi Angora rabbit. And to evaluate it as a candidate molecular marker association with performance traits which provides the reference for selective breeding. [Method] The single nucleotide polymorphisms in exon 2 of Hoxa4 were detected by direct sequencing in 208 Cangxi Angora rabbit, the association between SNP locus and performance traits were analyzed by software SAS 8.1. [Result] Only one SNP （c.298 T〉C） was detected in exon 2 of HoxoA gene, which caused an amino acid change from Ser to Pro （TCC-CCC）, which formed three genotypes （TF, TC, CC） with genotype TC was the dominate one （0.596 2） and allele T was the dominate one （0.562 9）. The genetic diversity analysis indicated the heterozygosity was 0.494 4, effective number of alleles was 1.977 9, and polymorphic information content （0.372 2）was in moderate polymorphism, indicating Hoxa4gene has a high genetic variability and has a potential to achieve on the genetic improvement of the rabbit group. The association analysis showed individuals with genotype CC have a significantly higher performance than TC （P〈0.05）at 73 days and significantly higher （P〈0.05）than CC and significantly higher （P〈0.01）than TC at 146 days. [Couclusion] SNP on exon 2 of Hoxa4 gene could be used as a molecular genetic markers to improve performance traits in Cangxi Angora rabbits.