Oosp1 Gene Plays an Essential Role in the Maintenance of the Primordial Follicle Reserve in the Mouse Ovary, Poster 47

Follicles are oocytes surrounded by granulose (somatic) cells that develop through the process of folliculogenesis, starting as primordial follicles then growing into primary, secondary, and then antral follicles before... [ view full abstract ]

Follicles are oocytes surrounded by granulose (somatic) cells that develop through the process of folliculogenesis, starting as primordial follicles then growing into primary, secondary, and then antral follicles before ovulation. The follicle reserve is the number of primordial follicles in the ovary at any given age and is ultimately depleted by the degeneration and progression through folliculogenesis until exhausted. Over-activation of the primordial follicle pool or loss of primordial follicle reserve in an early age leads to premature ovarian failure (POF). In humans, POF is defined as a cessation of meses prior to age 40 and affects 1-4% of women. The gene oosp1 (Oocyte secreted protein 1) is any important player in maintaining the primordial follicle reserve in mouse ovaries. Oosp1 is preferentially expressed in mouse oocytes and is conserved in humans. However, in humans, oosp1 is a unitary pseudogene, meaning it is a species-specific, unprocessed pseudogene with an active orthologue in another species. Using the CRISPR/Cas9 system, we successfully knocked out oosp1 in mice, as indicated by a reduction in mRNA levels in Het mice. Our preliminary findings suggest Het mice have a significant reduction in primordial follicles indicating that oosp1 is essential for mouse primordial follicle reserve.