The Role of Bone Morphogenetic Protein Receptor 1B (BMPR-1B) in Mouse Ovarian Follicular Development (#270)
Ovarian follicles development is regulated by a combination of endocrine and paracrine factors. Bone morphogenetic proteins and their receptors have been shown to be important in many aspects of this process. However, the mechanism by which BMPs regulate individual processes of ovarian function is poorly understood. A point mutation in BMPR-1B results in superovulation in the Booroola merino strain of sheep. We and others have reported that despite the increased ovulation rate and the reduced number of primordial follicles at birth, primordial follicle numbers by 2 years of age are higher in Booroola ewes than the non-Booroola merino ewe. This study aims to further elucidate the role of BMPR-IB in the female reproductive system by investigating passive immune neutralization of BMPR-1B in the mouse.
Prepubertal female Swiss mice were divided into 4 groups (n =5), each group was treated with (0.1ml) a subcutaneous injection of anti BMPR-IB alone, PMSG with and without anti BMPR-IB and the last group received non immune serum. The mice were injected daily for 7 days and then killed by CO2 asphyxiation. The ovaries were harvested and weighed before being immersion fixed in Bouin’s solution for histological study.
The ovaries from the anti BMPR-IB treated mice had a higher number of primordial follicles than the other groups. The number of Primary follicles was significantly (P≤0.05) reduced in ovaries from the anti BMPR-IB treated mice compared with the control and PMSG alone treated groups. Antral follicles numbers were significantly (P≤0.05) increased in ovaries from mice treated with a combination of PMSG and anti BMPIB compared with anti BMPR-IB alone groups.
In conclusion, anti BMPR-IB treatment lead to a reduction in the primordial to primary follicle recruitment rate which suggests signalling through this receptor has a pivotal role the regulation of the transition to primary follicles.