TYK2基因与家兔肠炎的易感性研究

目的]研究TYK2基因在家兔肠炎发生中的遗传效应,探讨其是否可以作为家兔抗病育种的辅助选择标记。方法]通过构建病例组-对照组肠炎兔群和低纤维诱导的肠炎兔群,PCR产物纯化后直接测序,以及qRT-PCR法检测TYK2基因在回肠和结肠组织中的mRNA表达水平。结果]发现TYK2基因外显子区域有5个c SNP,只有c.1477(c.1477,CT)位点发生非同义突变,导致氨基酸p.Leu 404 Phe(LF)的改变,C等位基因增加了肠炎的易感性(OR:1.36;95%CI 1.269~2.151;P=0.019),而等位基因T对肠炎的发生起到了一定的保护作用(OR:0.81,95%CI 0.352~0.960;P=0.018)。TYK2基因不同基因型和不同肠炎程度的mRNA水平均呈现差异表达(P0.05)。结论]TYK2(c.1477,CT)是家兔肠炎易感风险基因,为家兔的抗病育种提供了一个可靠的辅助选择标记。

Investigation of Genetic Susceptibility of TYK2 Gene in Rabbit Enteritis

Objective] To study the genetic effects of TYK2 gene in rabbit enteritis and to explore whether it could be used as a Marker-Assisted Selection (MAS) for resistance breeding in rabbits.Method] To construct case-control rabbit enteritis groups and low fiber induced rabbit enteritis groups, the PCR products were purified and sequenced directly, and the TYK2 gene mRNA levels in ileum and colon tissues were detected by qRT-PCR.Result] Five cSNPs were detected in exon region of TYK2 gene, and only c.1477 (c.1477, C>T) loci was non synonymous mutation, which caused to the change of amino acid p.Leu 404 Phe (L>F).The C allele increased the susceptibility of enteritis (OR: 1.36;95% CI 1.269~2.151;P=0.019), and the T allele was a protective effect on the occurrence of the enteritis (OR: 0.81, 95% CI 0.352~0.960;P=0.018).The TYK2 mRNA levels in different genotypes and in different degree of enteritis both presented significant difference (P<0.05).Conclusion] TYK2 (c.1477, C>T) is a susceptible risk gene of rabbit enteritis, and provides a MAS for the resistance breeding.