Anti-Müllerian hormone in female dromedary camel and its association with super-ovulatory response in embryo donors

Abstract

Anti-Müllerian hormone (AMH) has a conserved role in regulating the reproductive cycle in several species. Its circulating concentration reflects the size of the growing primordial follicle reserve and is a reliable predictor of superovulation response in embryo/oocyte donors. This study investigated the possible application of AMH measurement in dromedary camels (Camelus dromedarius) multiple ovulation embryo transfer programs. In experiment 1, the follicular cycle of synchronized and naturally cycling camels (n = 12) was monitored. Blood was collected at 6 timepoints in 2 consecutive cycles corresponding to emergence, mid-cycle, and dominance in both group and hormonal fluctuations were evaluated for repeatability of measurements within and between cycles. In experiment 2, the correlation between circulating AMH concentrations prior to initiation of superovulation and the outcome of superovulation was evaluated. The results were compared between donors with higher (n = 7) and lower than median (n = 8) AMH values. Mean AMH concentrations in synchronized and non-synchronized camels were 1.46 ± 0.15 and 0.95 ± 0.09, respectively. Intercycle and intracycle values of AMH showed high repeatability in camels of both groups (>96.4% and >92.74%, respectively) with significant correlations between values at different stages of the ovarian cycle (Emergence and mid-cycle: R² = 0.82; emergence and. dominance: R² = 0.86; Mid-cycle and dominance: R² = 0.93, P < 0.05). Total follicles, CLs, and recovered embryos were highly correlated with AMH values prior to superovulation (R² = 0.64, R² = 0.77, and R² = 0.64, respectively, P < 0.05). A greater number of developed follicles prior to mating (17.00 ± 2.09 vs. 7.62 ± 1.06), CLs (12.58 ± 1.36 vs. 5.12 ± 0.93), transferable (10.85 ± 1,31 vs. 3.37 ± 0.82), and spherical embryos (8.14 ± 1.07 vs. 2.62 ± 0.7) were observed in camels with higher than median concentrations of AMH (P < 0.05). Fluctuations in estradiol and progesterone did not affect variations in mean AMH values (r² < 0.19 and r² < 0.24, respectively, P > 0.05). In conclusion, highly consistent AMH values in dromedary camels are a reliable predictor of superovulation response and outcome in dromedary camels.