林麝MHC-DRA基因分析及与反刍亚目DRA基因比较  

Analysis of Forest Musk Deer(Moschus berezovskii) MHC-DRA Gene Exon 2 and Compared with Other Ruminantia

作　　者：夏珊[1,2] 岳碧松[1] 

机构地区：[1]四川大学生命科学学院,四川省濒危野生动物保护生物学重点实验室,成都610064 [2]成都师范学院化学与生命科学学院,成都611130

出　　处：《四川动物》2014年第4期481-486,共6页Sichuan Journal of Zoology

摘　　要：MHC-DRA基因仅在少部分物种如马、斑马、驴等具有多态性,DRA基因在其他哺乳动物中多为低多态性。由于MHC-DRA的低多态性,较少受到研究者重视,我们选取近缘物种牛的DRA基因引物,对四川养麝研究所的217只林麝进行DRA基因exon 2的序列扩增,得到2个林麝DRA基因,片段长度为260 bp,这2个基因仅有一个核苷酸同义突变,没有氨基酸突变。我们将所获得的林麝DRA基因与反刍亚目其他物种DRA基因进行氨基酸比对发现,我们扩增的序列为林麝DRA基因exon 2,编码MHCⅡ类分子的α1区域,而这段区域主要参与形成MHCⅡ类分子的多肽结合槽,根据Brown确定人类的抗原肽结合区位点,在参与比对的反刍亚目物种DRA基因中,抗原位点11、22、72、76存在氨基酸变异,而在这些位点上林麝的DRA基因没有变异,和大部分反刍亚目相同。同时我们发现大部分反刍亚目物种之间氨基酸突变的位点大都在非抗原结合位点。The major histocompatibility complex （MHC） is one of the most important elements in immune system in almost all vertebrates. Mammals usually show low MHC-DRA polymorphism with the exception of horse, zebra and donkey. Cattle-specific primers DRA-F and DRA-R were used to amplify a 260 bp fragment of exon 2 of the DRA locus from genmonic DNA of 217 individuals of Chinese forest musk deer. We found 2 alleles on locus DRA and named them as Mobe-DRA^＊1 and Mobe-DRA^＊2. There was only one nucleotide differences （no amino acid differences） between the two DRA alleles. We downloaded 31 DRA sequences of Ruminantia from GenBank, and reconstructured the molecular phylogenetic relationship within Pecora using the Bayes Inference （BI）. The phylogenetic relationships between these alleles supported the monophyly of Cervidae, Bovidae and Cetancodonta, and placed Moschidae as a sister group to Cervidae/Bovidae. The difference in 33 DRA sequences shows that changes in amino acid sequence fall outside the antigen binding site （ABS）.

关 键 词：林麝 MHC DRA 反刍亚目 

分 类 号：Q78[生物学—分子生物学]