Screening,analysis And Functional Study Of Tibetan Sheep Disease Resistant Immune Genes

Tibetan sheep live in the plateau for a long time and have strong disease resistance and adaptability.Objective: This study aims to discover the immune genes of disease resistance in Tibetan sheep,with a view to provide a preliminary basis for the research on resistance of Tibetan sheep.Methods: In this study,the small-tailed Han sheep was used as a control.The RNA-Seq technology was used to analyze the differential expression of disease-resistant immune gene transcriptomics in high-prototype and Euler-type Tibetan sheep,Real-Time PCR was used for functional verification.Results:(1)Comparison of Euler-type Tibetan sheep with small-tailed Han sheep,RNA-Seq sequencing results showed that Euler-type Tibetan sheep had significant differences in expression of 253 genes relative to small-tailed Han sheep,of which 104 genes were significantly up-regulated and 149 genes Significantly down-regulated.The results of GO enrichment analysis showed that differential gene enrichment was in functional categories such as multicellular biological processes,and cell surface receptor signaling pathways.The results of KEGG enrichment analysis showed that genes with up-regulated expression were more enriched Significant pathways include graft-versus-host disease,TGF-bate signaling pathway,BCR signaling pathway and allogeneic rejection.Among them,the genes CD19 and CD79 B involved in the BCR signaling pathway,the genes TNFRSF13 B and TNFRSF13 C involved in the IgA intestinal immune network,and the gene EGLN3 in the HIF-1 signaling pathway were all up-regulated.(2)The RNA-Seq sequencing results of high-profile Tibetan sheep compared with small-tailed Han sheep showed that there were 280 gene expression differences between high-profile Tibetan sheep and small-tailed Han sheep,among which 104 genes were significantly up-regulated and 176 genes were significantly down-regulated.The results of GO enrichment showed that the differential genes of high-prototype Tibetan sheep and small-tailed Han sheep were enriched in 2945 GO functional categories,of which the up-regulated genes were mainly enriched in the immune response and immune system process.The results of KEGG enrichment showed that the up-regulated genes were enriched the more significant pathways which are the TCR signaling pathway,phagocytic vesicles,cell adhesion molecules,antigen processing and presentation,etc.Among the genes involved in the TCR signaling pathway are Vav1,GRAP2,CD3 D,CD3G and CD3 E,these genes are up-regulated encoding proto-oncogene,GRB2-related adaptor protein 2 and T cell surface glycoprotein CD3?,?,? chain,and chemokine-related genes Vav1,CCL3 and CCL16 are up-regulated,Encoding proto-oncogenes and CC motif chemokines 3 and 16,respectively.Compared with the small-tailed Han sheep,the 5 up-regulate and 5 down-regulate genes of high-prototype Tibetan sheep and Euler-type Tibetan sheep were randomly selected to test by Real-Time PCR respectively.The results showed that the differential expression trend was consistent with RNA-Seq results.Conclusion: Compared with small-tailed Han sheep,the expression of 253 genes in Euler-type Tibetan sheep is significantly different.Among them,genes such as CD19,CD79 B,TNFRSF13B,TNFRSF13 C and EGLN3 are up-regulated in the spleen tissue of Euler-type Tibetan sheep;A total of 280 genes in Han sheep are significantly different in expression.Among them,genes such as Vav1,GRAP2,CD3 D,CD3G,CD3 E,CCL3,and CCL16 are up-regulated in the immune system of high-prototype Tibetan sheep.The result will provide a preliminary basis for the research of Tibetan sheep's disease resistance deeply.