Splenic comparative transcriptome analysis reveals the immunological mode of undomesticated Gayal (Bos frontalis) for...

The utilization of transcriptome technology in the identification of pivotal regulatory genes associated with immunity is of paramount importance. Previous studies have shown that undomesticated gayal (Bos frontalis) may have higher humoral responses which is comparable to yaks. However, research on immune function of gayal is limited, and comparisons with different breeds are rarely reported. The objective of this study was to inspect the immune status and compare splenic differential expression genes (DEGs) through comparative transcriptome analysis of gayal and domesticated local cattle (Yunan yellow cattle).

Serum immunological status investigation showed the better humoral immune status and lower levels of pro-inflammatory cytokines of gayal when compared to the local cattle. Spleen RNA-seq showed that 708 DEGs (365 up- and 343 down-regulated genes) were obtained between the gayal and local cattle. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis showed that immune system pathways, immune disease pathways, and chemotaxis-related molecular function of gayal were significantly enriched, whereas T cell-related cellular component and biological process were downregulated in the gayal. Correlation analysis shown that CD1, CD36, CD38, CD179a, CD179b, CXCL8, IGCGAMMA, IGH, IGHG1, IGLL1, IL1R2, SERPINB, and SERPINB4 had positive correlations with splenic IgA, IgD, IgE, IgG, and IgM, respectively (R > 0.5, P < 0.05). ANPEP, BVD1.23, CD1E, CD3D, CD3E, CD3G, CD5, CD8 A, HBB, IDO1, LCK, MGC126945, MHC1, TRAV, TRBV, and ZAP70 had negative correlations with splenic IgA, IgD, IgE, IgG, and IgM, respectively (R < -0.5, P < 0.05).

Our results reveal the immunological mode of gayal with high-level humoral immunity and enhanced splenic immunoglobulin gene expression and B cell differentiation, which may enable gayal to adapt to the harsh environments.