Based on the Co-Evolution of lncRNAs-Microbiota and Metabolites in Rumen Epithelium to Analyze the Adaptation Characteristics of Tibetan Sheep to Nutrient Stress in the Cold Season

Abstract

Based on the serious phenomenon of Tibetan sheep “growing strong in warm seasons and losing weight in cold seasons”, this study explores the regulation of lncRNAs, microbiota, and metabolites in the cold season adaptation of Tibetan sheep from the perspective of the co-evolution of the host genome (first genome) and microbiome (second genome). RNA-seq results showed that 172 DE lncRNAs were identified in the rumen epithelium of Tibetan sheep in warm and cold seasons, of which 87 DE lncRNAs were significantly up-regulated in cold seasons. KEGG enrichment showed that target genes of up-regulated lncRNAs were significantly enriched in TNF signaling and oxidative phosphorylation pathways. LncRNA-mRNA regulatory network indicated that DE lncRNAs were involved in nutrient stress in the cold season by targeting ATP1B2, CADPS, TLR5, and UGT1A6. Correlation analysis showed some lncRNAs were significantly correlated with acetic acid, propionic acid, butyric acid, and rumen epithelial histomorphology and had a negative correlation with Butyrivibrio-2 and Succiniclasticum (p < 0.05). In addition, differential metabolites bilirubin and lncRNAs were co-enriched in the bile secretion pathway. lncRNAs played an important role in the adaptation process of Tibetan sheep in the cold season, and mediate the host to participate in nutrient absorption, energy utilization, and immune response, indicating that the host genome and microbial genome promote Tibetan sheep to adapt to nutrient stress in the cold season through co-evolution.