Polymorphisms Of MHC-DPB1 Gene Exon 2 In Rhesus Macaques (Macaca Mulatta)

MHC gene diversities are widely existence in rhesus macaque (Macaca mulatta) population from different geographical origin; it can influence the stability, reliability and reproducibility of the results of the experiments using macaques as models.Therefore, in order to evaluate the results of research and facilitate the use of rhesus macaques from these populations in biomedical research and their protection, it's very important to understanding the immnuogenetics background of these rhesus macaque populations. The exon 2 of Mamu-DPB1 alleles of 217 Sichuan wild rhesus macaques were analyzed by using denatured gradient gel electrophoresis (DGGE), cloning and sequencing, and following results were obtained:1) A total of 59 Mamu-DPB1 alleles were obtained,52 alleles of which were novel sequences that had not been documented in the previous publications. The most frequent alleles were Mamu-DPB1*30 in total population(allelic frequency;0.068),-DPB1*30 in Xiaojin(0.081), Mamu-DPB1*04 in Heishui (0.103),-DPB1*32 in Bazhong (0.107),-DPB1*23 in Hanyuan(0.071),-DPB1*04 in Jiulong(0.81),-DPB1*04 in Danba(0.071), DPB1*04 in Beichuan(0.107);2) 67 species-specific amino acid residues, located at 51 positions, were identified from the comparison between the Mamu-and Mafa-DPB1 alleles. Of these species-specific amino acid residues,39 were Mamu-DPBl-specific amino acid.residues, 33 of which were in the 52 novel Mamu-DPB1 alleles;3) A phylogenetic tree was constructed from a neighbor-joining analysis of the MHC-DPB1 exon 2 sequences from different species, and we can also observe trans-species polymorphism phenomenon of species in the phylogenetic tree, which indicated that the appearance of the new alleles may.be caused by convergent evolution under the same or similar natural selection press; 4) Results of the average genetic distance were calculated by MEGA4.0 with method of Nei-Gojibori-p (high to low):Hanyuan> Xiaojin> Jiulong> Beichuan> Danba> Heishui>Bazhong, which indicates that the average genetic distance influenced by amimo acid disparity is the highest in Hanyuan and the lowest in BaZhong. Results of the average genetic distance were calculated by MEGA4.0 with method of Kimular-2-parameters (high to low):Hanyuan> Xiaojin> Bazhong> Beichuan> Jiulong>Heishui>Danba, which indicates that genetic diversity is highest in Hanyuan and the lowest in Danba.All of the data show that the MHC-DPB1 of rhesus seemed to be provided with high polymorphism and also demonstrated that significant genetic different has occurred between Chinese and Indian rhesus macaque population. Accordingly, more and more rhesus macaques coming from different geographical groups should be used in the study about MHC in the future, then analyze the backgrounds of MHC between the different geographical groups, and we can reveal the backgrounds of MHC in China-origin rhesus macaques finally, which is significant for the use of Chinese rhesus macaques in future.