Plasma extracellular vesicle miRNAs as potential biomarkers for superstimulatory response in cattle

The objective of this study was to analyze the extracellular vesicle microRNA (EV-miRNA) expression profiles in the blood plasma of heifers with variable response to superstimulation. Oestrous cycles of crossbred beef heifers were synchronized. On Day 10 after standing oestrus (=Day 0), superstimulation was induced by the administration of decreasing doses of follicle stimulating hormone twice a day for 4 d with PG administered with the 6th FSH injection followed by artificial insemination. Blood samples were collected on Day 7 of the unstimulated (U) and superstimulated (S) cycle from each heifer. All heifers were slaughtered on Day 7 of the S cycle. A subset of high (H, n=3) and low (L, n=3) responder heifers was selected depending on the ovarian response to superstimulation. Small RNA libraries were constructed and miRNA profiles were sequenced.