A potential role of fibrillin-1 (FBN1) mRNA and asprosin in follicular development in water buffalo.

Fibrillin-1 (FBN1) functions as a structural protein in the ovary, while the role of its protein product asprosin remains unknown. Both proteins are encoded by the FBN1 gene and when it is cleaved at the C-terminal end, asprosin is produced. Asprosin is associated with various metabolic parameters and sex-related hormones in women. One goal of this research was to quantify FBN1 and the presumed asprosin receptor, olfactory receptor family 4 subfamily M member 1 (OR4M1) mRNA in water buffalo granulosa cells and correlate them to aromatase (CYP19A1) gene expression. A second goal was to determine the effect of asprosin on follicular growth in vivo. In Exp. 1, ovaries were collected from a local slaughterhouse, follicular fluid and granulosa cells from small (  0.10) between the two sizes of follicles. Abundance of FBN1 mRNA was positively correlated with CYP19A1 (r = 0.55, P < 0.05) and OR4M1 mRNA (r = 0.50, P < 0.06) across follicle sizes. In Exp. 2, cows treated with asprosin revealed a greater follicle growth rate from day 0-2 (63.4% increase in diameter) than placebo cows (36.8% increase in diameter) post-injection, and more follicles from asprosin treatment vs. control group (100% vs. 20%; P < 0.05) ovulated within 2 days. These findings suggest that FBN1 may be developmentally regulated in follicular cells, and that asprosin may induce follicular growth in buffaloes, but further studies will be required to determine if asprosin directly regulates estradiol production during follicle development.