猕猴MHC-DPB1基因外显子2多态性研究

猕猴(Macaca mulatta)是最理想的医学实验灵长类动物, 且为国家二级保护动物。为了解中国猕猴主要组织相容复合体(Major histocompatibility complex, MHC)基因的遗传多态性背景, 为它们在生物医学研究中的应用及其遗传资源的保护提供一定的科学依据, 文章采用变性梯度凝胶电泳(Denaturing gradient gel electrophoresis, DGGE)和克隆测序技术分析了106个四川野生猕猴MHC-DPB1基因的exon 2, 共检测到21个Mamu-DPB1等位基因, 其中有15个为本研究中首次发现的新等位基因; 从整个大的猕猴群体(106个个体)来看, 等位基因频率最高的是Mamu-DPB1*30(0.1120); 单独从不同地理群体来看, 最高等位基因频率分别为: 小金-DPB1*30 (0.1120), 黑水-DPB1*04 (0.1702), 巴中-DPB1*32 (0.1613), 汉源-DPB1*30(0.1120), 九龙-DPB1*04(0.1139); 氨基酸序列比对发现, 猕猴Mamu-DPB1等位基因编码的氨基酸序列中, 有12个氨基酸残基变异位点表现出物种特异性, 其中有9个位于新发现的15个Mamu-DPB1等位基因氨基酸序列中; 不同物种来源的DPB1等位基因系统发生树表明, 猕猴与其近缘物种食蟹猴(Macaca fascicularis)的DPB1等位基因间存在着跨种多态(Trans-species polymorphism)现象。研究还表明, MHC-DPB1等位基因在中国猕猴群体和先前为主要研究对象的印度猕猴群体间具有较大的差异。

Polymorphism of MHC-DPB1 gene exon 2 in rhesus macaques (Macaca mulatta)

Rhesus macaque (Macaca mulatta) has long been used as an experimental model animal for biomedical research and was under the key state protection (class II) from Chinese government. In order to facilitate the use of Chinese rhesus macaques in biomedical research and their protection based on better understanding of the major mistocompability complex (MHC) genes in these macaques, the exon 2 of Mamu-DPB1 genes were determined in 106 wild rhesus macaques using DGGE, cloning and sequencing. A total of 21 Mamu-DPB1 alleles were obtained, of which 15 alleles were novel sequences that had not been documented previously. Mamu-DPB1*30 was the most frequent allele in the whole large population comprising all 106 rhesus macaque individuals (0.1120) and in Xiaojin population (0.1120), Mamu-DPB1*04 in Heishui (0.1702), -DPB1*32 in Bazhong (0.1613), -DPB1*30 in Hanyuan (0.1120), and -DPB1*04 in Jiulong (0.1139). The alignment of the amino acids sequences showed that 12 variable sites were species-specific, of which 9 sites occurred in the putative amino acids sequences of the 15 novel Mamu-DPB1 alleles. Trans-species polymorphism was observed on the phylogenetic tree based on the DPB1 alleles of rhesus macaques and cynomolgus (Macaca fascicularis). In addition, these results also demonstrated that significant genetic differentiation has occurred between Chinese and Indian rhesus macaque population.