Sunflower oil supplementation affects the expression of miR-20a-5p and miR-142-5p in the lactating bovine mammary gland. Bos taurus

Background : In lactating cow, a sunflower oil supplementation modulated the milk composition and the mammary genes expression whose mechanisms of regulations are unclear. Results : This lipid supplementation provoke, in mammary gland, the down regulation of microRNA miR-20a-5p and miR-142-5p, which are predicted to target genes previously determined as differentially expressed including those involved in lipid metabolism. Conclusion : Those two miRNA are good candidates to explain lipogenic genes regulations after sunflower oil supplementation. Significance : The current study clarified the nutriregulation of miRNA in the mammary gland. Overall design: MiRNomes obtained by NGS sequencing of mammary gland of Holstein cows at the peak of lactation received a low forage diet supplemented or not with 4% of sunflower oil were compared. MiRNA differentially expressed confirmed by RT-qPCR were related to differentially expressed genes list previously identified in the same samples.