Genetic variation and selection in the major histocompatibility complex Class II gene in the Guizhou pony

PeerJ

article

Chang Liu¹  Hongmei Lei¹  Xueqin Ran¹  Jiafu Wang¹ 

[1] College of Animal Sciences, Guizhou University;College of Pharmacy, Guizhou University of Traditional Chinese Medicine;Tongren University

关键词: Guizhou pony;    MHC;    Antigen binding sites;    Evolution process;    Adaptation;   

DOI  :  10.7717/peerj.9889

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The Guizhou pony (GZP) is an indigenous species of equid found in the mountains of the Guizhou province in southwest China. We selected four regions of the equine leukocyte antigen (ELA), including DQA, DRA, DQB, and DRB, and used them to assess the diversity of the major histocompatibility complex (MHC) class II gene using direct sequencing technology. DRA had the lowest dN/dS ratio (0.560) compared with the other three loci, indicating that DRA was conserved and could be conserved after undergoing selective processes. Nine DQA, five DQB, nine DRA, and seven DRB codons were under significant positive selection at the antigen binding sites (ABS), suggesting that the selected residues in ABS may play a significant role in the innate immune system of the GZP. Two GZP alleles were shared with Przewalski’s horse, and six older GZP haplotypes had a better relationship with other horse species by one or two mutational steps, indicating that the GZP may be a natural ancient variety of equid. The specific diversity of ABS and the numbers of unique haplotypes in the evolutionary process affords this species a better genetic fitness and ability to adapt to the native environment.

【 授权许可】

CC BY