Project description:A healthy rumen is crucial for normal growth and improved production performance of ruminant animals. Rumen microbes participate in and regulate rumen epithelial function, and the diverse metabolites produced by rumen microbes are important participants in rumen microbe-host interactions. SCFAs, as metabolites of rumen microbes, have been widely studied, and propionate and butyrate have been proven to promote rumen epithelial cell proliferation. Succinate, as an intermediate metabolite in the citric acid cycle, is a final product in the metabolism of certain rumen microbes, and is also an intermediate product in the microbial synthesis pathway of propionate. However, its effect on rumen microbes and rumen epithelial function has not been studied. It is unclear whether succinate can stimulate rumen epithelial development. Therefore, in this experiment, Chinese Tan sheep were used as experimental animals to conduct a comprehensive analysis of the rumen microbiota community structure and rumen epithelial transcriptome, to explore the role of adding succinate to the diet in the interaction between the rumen microbiota and host.
Project description:As the unique organ, rumen plays vital roles in providing products for humans, however, the underlying cell composition and interactions with epithelium-attached microbes remain largely unknown. Herein, we performed an integrated analysis in single-cell transcriptome, epithelial microbiome, and metabolome of rumen tissues to explore the differences of microbiota-host crosstalk between newborn and adult cattle models. We found that fewer epithelial cell subtypes and more abundant immune cells (e.g., Th17 cells) in the rumen tissue of adult cattle. Metabolism-related functions and oxidation-reduction process were significantly upregulated in the adult rumen epithelial cell subtypes. The epithelial Desulfovibrio was significantly enriched in the adult cattle. To further clarify the role of Desulfovibrio in host’s oxidation-reduction process, we performed metabolomics analysis of rumen tissues and found that Desulfovibrio showed a high co-occurrence probability with the pyridoxal in the adult cattle compared with newborn ones. The adult rumen epithelial cell subtypes also showed stronger ability of pyridoxal binding. These indicates that Desulfovibrio and pyridoxal likely play important roles in maintaining redox balance in adult rumen. The integrated analysis provides novel insights into the understanding of rumen function and facilitate the future precision improvement of rumen function and milk/meat production in cattle.
Project description:Ruminant livestock are one of the major contributors to carbon emission contributing the global warming issue. Methane (CH4) produced from enteric microbial fermentation of feed in the reticulo-rumen are known to differ between sheep with different digestive function and fermentation products such as metabolites. However, the molecular mechanism underpinning differences in methane emission remains to be fully elucidated. We extracted a membrane and cytosolic protein fraction of rumen epithelium proteins from both high (H) and low (L) CH4 emitting sheep. Protein abundance differences between the phenotypes were quantified using SWATH-mass spectrometry. We identified 92 proteins annotated as cell surface transporters, of which only solute carrier family (SLC) 40A1 had a greater fold change of protein expression in the high methane emission phenotype. The main difference in protein abundance we found were related to the metabolism of glucose, lactate and processes of cell defence against microbes in the epithelium of sheep in each group. To best of our knowledge, this represents one of the most comprehensive proteomes of ovine rumen epithelium to date.