Co-expression and evolution of Mafa-B alleles in Macaca fascicularis based on third-generation sequencing

Abstract:

[Background] Major histocompatibility complex (MHC) is highly polymorphic, thus influencing the outcome of biomedical experiments. Particularly, specific MHC-B alleles are closely related to the development of various diseases. Macaca fascicularis (Mafa) is an important animal model for conducting biomedical research. Currently, Mafa-B alleles in Mafa have not been comprehensively characterized. [Objective] To explore the comprehensive information on Mafa-B alleles in Mafa and to identify co-expression and evolution of Mafa-B alleles. [Methods] Through third-generation sequencing, the genomic information of MHC-B of Mafa was obtained. Then, we designed specific primers to amplify Mafa-B alleles in a cohort of 33 Vietnamese Mafa individuals and characterized Mafa-B alleles with multiple bioinformatics methods. [Results] On the basis of information of 92 Mafa-B alleles, we identified 65 novel Mafa-B alleles. Among them, 8 alleles were identical to sequences previously reported in Mafa of other geographical origins and 32 were also found in macaque populations. In addition, we identified 7 high-frequency Mafa-B lineages and 7 pairs of co-expressed Mafa-B alleles, and detected one potential recombination event. Evolutionary analysis revealed the high similarity of Mafa-B sequences in Mafa from different geographical origins.[Conclusion] These co-expressed Mafa-B alleles in Vietnamese populations have undergone selection pressure by certain antigens, and Mafa populations of different geographical origins may fine-tune the Mafa-B sequences in response to pathogens. This study lays a foundation for elucidating the genetic background of MHC in Mafa.