藏酋猴Mhc-DPB1基因exon2的多态性  

Polymorphic analysis of Mhc-DPB1 gene exon 2 in Tibetan macaques(Macaca thibetana)

作　　者：李佳薏[1] 姚永芳[1] 周亮[2] 徐怀亮[1] 

机构地区：[1]四川农业大学动物科技学院,雅安625014 [2]四川省医学科学院四川人民医院实验动物研究所,成都610212

出　　处：《遗传》2012年第11期1417-1426,共10页Hereditas（Beijing)

基　　金：国家自然科学基金资助项目(编号:30970383);教育部"长江学者和创新团队发展计划"创新团队项目(编号:IRT0848);四川省教育厅自然科学基金重点项目(编号:08ZA076)

摘　　要：主要组织相容性复合体(Major histocompatibility complex,MHC)对许多疾病的易感性和抵抗力起着重要的作用。为了解藏酋猴(Macaca thibetana)的MHC基因遗传背景,以促进藏酋猴遗传资源的保护及其在生物医学研究中的应用,文章采用PCR扩增和克隆测序等方法对来自四川地区的70个藏酋猴样品的Mhc-DPB1基因exon 2进行了检测和分析。首次在藏酋猴中获得了18个DPB1等位基因(Math-DPB1),其中1个为假基因(Math-DPB1*01:06N)。18个等位基因中,Math-DPB1*06:01:01(67.14%)的阳性检出率最高,其次为Math-DPB1*01:03:01(37.14%)、Math-DPB1*09:02(25.71%)和Math-DPB1*22:01(15.71%)。氨基酸序列比对发现,藏酋猴Math-DPB1等位基因编码的氨基酸序列中,有5个氨基酸残基变异位点表现出物种特异性。不同物种来源的DPB1等位基因系统发生树表明,藏酋猴、猕猴(Macaca mulatta)和食蟹猴(Macaca fascicularis)的DPB1等位基因不是以物种特异性方式聚类,而是种间混聚在一起,并显示出明显的跨物种多态性(Trans-species polymorphism)。选择性检验表明,平衡选择(Balancing selection)在维持Math-DPB1基因的多态性中起着重要的作用。Major histocompatibility complex （MHC） molecules play an important role in the susceptibility and/or resis- tance to many diseases. To gain an insight into the MHC background of the Tibetan macaques （Macaca thibetana）, and thereby facilitate their protection and application in biomedical research, the second exon of the Mhc-DPB1 genes from 70 Tibetan macaques in Sichuan Province were characterized by PCR, cloning, sequencing, and statistical analysis. A total of 18 Mhc-DPB1 alleles were identified from Tibetan macaques, of which one （Math-DPB1＊01：06N） was a pseudogene. Math-DPB1＊06：01：01 （67.14%） was the most frequent allele in all the 18 alleles detected, followed by Math-DPB1＊ 01：03：01 （37.14%）, Math-DPB1＊09：02 （25.71%）, and Math-DPB1＊22：01 （15.71%）. The alignment of putative amino acid sequences of the 18 Math-DPB1 alleles showed that 5 variable sites were species-specific to Tibetan macaques. A phyloge- netic tree constructed using DPB1 alleles in difference species demonstrated that the alleles for Math-DPB1, Mamu-DPB1, and Mafa-DPB1 tended to mix together, rather than cluster into a separate branch in a species-specific fashion, and the Trans-species polymorphism was also observed in the phylogenetic tree. Selection analysis revealed that balancing selection may play an important role in maintaining the polymorphism of Math-DPB1 genes.

关 键 词：藏酋猴 主要组织相容性复合体Ⅱ类 DPB1基因 遗传多态性 跨物种多态 

分 类 号：Q95-331[生物学—动物学] Q75