Li Jingjing, Yang Chaowu, Ran Jinshan, Jiang Xiaosong, Du Huarui, Li Zhiqiang, Liu Yiping, Zhang Long
1Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu Campus, Chengdu, 611130 China.
3Sichuan Animal Science Academy, Chengdu, 610066 China.
3 Biotech. 2018 Nov;8(11):483. doi: 10.1007/s13205-018-1504-8. Epub 2018 Nov 14.
Chicken Mx1 gene, as a positive antiviral gene, has been reported to provide resistance to several viruses especially avian influenza virus. In present research, the genotype frequency contributions of chicken Mx1 polymorphisms were characterized in five lowly selected as well as one moderately selected Sichuan native chicken populations and two highly selected commercial chicken breeds. Together with two newly-identified mutation sites (r.8A > G and r.1257T > C), a total of 13 single nucleotide polymorphisms (SNPs), including seven nonsynonymous mutation and six synonymous mutation, were found in the coding region of chicken Mx1 gene. Local Chinese chicken populations exhibited higher nucleotide diversity than commercial populations. Moreover, amino acid substitution sites as well as positive selection sites were located only in the domain not determined and GTPase domain, implying that amino acids mutations were likely needed in the modulatory and structural regions to better adapt the environment. Collectively, our results suggest that different selection pressures greatly influenced the genotype frequency contributions of chicken Mx1 gene. Understanding the interaction between genetic diversity and artificial selection may help us to better select and breed superior domestic chickens.
鸡Mx1基因作为一种阳性抗病毒基因，据报道能对多种病毒尤其是禽流感病毒产生抗性。在目前的研究中，对五个低选择度以及一个中等选择度的四川本地鸡群体和两个高选择度的商业鸡品种中鸡Mx1基因多态性的基因型频率贡献进行了表征。连同两个新鉴定的突变位点（r.8A＞G和r.1257T＞C），在鸡Mx1基因的编码区共发现了13个单核苷酸多态性（SNP），包括7个非同义突变和6个同义突变。中国本地鸡群体表现出比商业群体更高的核苷酸多样性。此外，氨基酸替换位点以及正选择位点仅位于未确定结构域和GTP酶结构域，这意味着在调节和结构区域可能需要氨基酸突变以更好地适应环境。总体而言，我们的结果表明不同的选择压力极大地影响了鸡Mx1基因的基因型频率贡献。了解遗传多样性与人工选择之间的相互作用可能有助于我们更好地选择和培育优良家鸡。
