Anti-Müllerian hormone concentration in sheep and its dependence of age and independence of BMP15 genotype: An endocrine predictor to select the best donors for embryo biotechnologies

Abstract Embryo biotechnologies contribute significantly to the genetic enhancement of livestock, although their efficiency remains limited in sheep, mainly owing to variable ovarian responses to gonadotropins. At present, anti-Mullerian hormone (AMH), which is produced by the granulosa cells of the small antral follicles, is a reliable endocrine marker of the ovarian follicle reserve in many species. The expression of AMH in granulosa cells was shown to be stimulated by bone morphogenetic proteins (BMPs) in vitro , so a mutation affecting the BMP15 gene might modulate AMH production in vivo . The present study aimed to assess plasma AMH concentrations before puberty in two groups of Rasa Aragonesa ewes that were carrying (R+) or not carrying (++) the prolific FecX R allele and to relate them with their AMH concentrations at adulthood. Additionally, we sought to establish in both genotypes whether AMH measurements during a laparoscopic ovum pick-up (LOPU) program could be predictive of the number of ovarian follicles (≥3 mm) and recovered cumulus-oocyte complexes (COCs). No differences in AMH were found between the R+ and ++ ewes before puberty or during the adult age. Before puberty, the AMH concentration tended to increase from 3 to 4.5 months and to decline at 6 months to levels similar to those observed later in adults (333.8 ± 73.3, 483.2 ± 135.5, and 184.1 ± 38.2 pg/mL, respectively; P FecX R allele did not affect plasma AMH levels. During adulthood, AMH proved to be a good predictor of the ovarian response to FSH stimulation. Such an indicator could therefore be used to improve the performance of embryo biotechnologies in sheep.