不同鸡种DMA基因序列比较分析  

Comparative analysis of DMA gene sequences in different chicken breeds

作　　者：孔令琳[1] 郑圣晗 陈颖[1] 朱鹏飞[1] 吴允[1] 郭其新[1] 陈国宏[1] 常国斌[1] 

机构地区：[1]扬州大学动物科学与技术学院,江苏扬州225009

出　　处：《浙江农业学报》2017年第4期560-565,共6页Acta Agriculturae Zhejiangensis

基　　金：国家科技支撑计划(2015BAD03B03);江苏高校优势学科建设工程资助项目

摘　　要：DMA(major histocompatibility complex,classⅡ,DM alpha)基因是鸡MHCⅡ类典型基因座,与免疫反应和抗病性密切相关。试验对25个不同鸡种的DMA基因序列进行目标捕获测序,以NCBI上Gallus gallus的DMA基因序列作为参考序列,通过MEGA6软件进行序列比对分析,筛选出不同鸡种DMA基因序列上的SNPs和Indels(insertion-deletion)位点以及氨基酸的变化,并根据基因序列的差异构建系统进化树,探究不同鸡种间的同源性。结果表明,DMA基因呈现出丰富的多态性,突变和缺失位点集中于外显子上,且多个鸡种在第2外显子发生多位碱基缺失,导致其氨基酸序列发生极大改变,可能是不同鸡种产生抗性差异的主要因素;同时进化树也显示,斗鸡、藏鸡等抗性较好的鸡种间有相近的亲缘关系,同源性较高。以上结果表明,DMA基因有丰富的遗传多样性,且与不同鸡种的先天免疫与抗病特性差异相关,第2外显子中94 496~94552的Indels可以作为鸡免疫特性的候选标记。DMA （major histocompatibility complex, class Ⅱ , DM alpha） is a typical gene of chicken MHC class Ⅱ , which is closely related to the host immune response and disease resistance. In this study, we detected DMA gene of 25 different chicken breeds by target capture sequencing and used DMA gene sequence of Gallus gallus in NCBI as the reference. Then we analyzed gene sequence by MEGA6, screened SNPs （ single nucleotide polymor-phism） and Indels （insertion-deletion） of DMA gene sequences in different chicken breeds. Finally, we constructed the phylogenetic tree according to the differences in gene sequences. The results revealed that the DMA gene ap-peared rich polymorphism. SNPs and Indels were concentrated on exons mostly. Meanwhile, base deletions on exon2 caused the great changes in its translated products. In addition, the phylogenetic tree showed the chickens with better disease resistance such as Tibetan chicken and game chicken had high homology. The above results demonstrated that the DMA gene is rich in genetic diversity which is related to the differences in innate immunity and disease re-sistance in chicken breeds. The Indels in exon 2 94 496-94 552 can be used as a candidate marker of chicken im-mune characteristics.

关 键 词：鸡 DMA基因 MHC SNPS INDELS 进化树 

分 类 号：S831[农业科学—畜牧学]