W151Interactions Between Diet and Rumen Transcriptomic Pathways and Association with Methane Emissions
Time: 8:20 AM
A gene expression correlation network was constructed from rumen wall transcriptomes of 24 sheep fed two different amounts and qualities of feed and measured for a range of phenotypes, including CH4 production.
The network contained two major negatively correlated gene sub-networks representing the epithelial and muscular layers of the rumen wall. Few genes from the muscle sub-network responded to diet. In contrast, the expression of cell cycle genes (including BRCA1) and a number of metabolic processes, was positively correlated with dry matter intake (DMI), ruminal short chain fatty acid concentrations and CH4 production. The majority of gene expression and phenotypic variation was explained by feed consumption level. Conversely, feed quality explained the majority of the variation in expression of the epithelium-innate immunity genes (including epithelial regulatory factors GRHL3 and OVOL1). The expression of this gene set had the strongest, but still weak and negative, relationship with CH4 corrected for DMI (CH4 yield).
The rumen epithelium appears to be more responsive to diet than the muscular layers. Transcriptomics shows promise for the identification of pathways underlying the interaction between the host and the methane production systems in the rumen, which will contribute to the future reduction of methane per unit of livestock production.