Single-cell transcriptomic analysis reveals the landscapes of key metabolic tissues in lactating dairy cows

The complicated biological process of how dairy cows convert indigestible nutrients for humans into nutritious milk is orchestrated by various tissues. Here, we deciphered the single-cell landscapes of 10 bovine tissue types covering 88,013 cells. We characterized the metabolic features of epithelial cell subtypes that exert unique functions to the tissues of residence. We also identified the cell subtypes that are essential for the transport of certain nutrients. Th17 cells were specifically enriched in the rumen, reticulum, and omasum tissues and predominantly interacted with the epithelial cell subtypes with high potential uptake capacities of short-chain fatty acids through IL-17 signaling. The comparison between IL17RAhighIL17RChigh cells and other cell types explained the important role of Th17 cells in regulating the epithelial cellular transcriptional response to nutrients transport in these three tissues. The findings enhance our understanding of ruminants biology and open new avenues for an improved animal production in dairy cows. Overall design: Single-cell RNA sequencing for 88,013 cells from 9 tissues types of dairy cow.