Prolongation of Ovarian Follicle Levels by Over-expression of Foxl2 or Foxo3

Tuesday, October 09, 2012 — Poster Session I
1:00 p.m. – 3:00 p.m	Natcher Conference Center, Building 45	NIA	AGING-7

Authors

• E Pelosi
• S Omari
• M Michel
• A Forabosco
• C Ottolenghi
• D Schlessinger

Abstract

Follicles, the basic functional units of the mammalian ovary comprise two functional populations, resting and growing. The resting follicle pool represents the "ovarian reserve" from which follicles will be recruited for maturation throughout life. The size of the ovarian reserve is a critical indicator of female fertility, and also the proximate determinant of reproductive lifespan. In women, most fetal germ cells are discarded until the number of primordial follicles reaches about 700,000 at the end of folliculogenesis (the major process of ovarian development); it then declines during reproductive life to about 1,000, when menopause ensues about the age of 51. In Premature Ovarian Failure (POF), which affects 1% of the female American population, follicles reach a low level prematurely because of the accelerated depletion of primordial follicle reserve (Fig. 1). However, the mechanisms involved in the balance between follicle formation, maintenance and maturation have remained elusive, and include the undetermined relation of follicle recruitment to aging of the ovary. Here we have studied transgenic mice over-expressing the forkhead transcription factors Foxl2 or Foxo3, to show how they function as key factors in formation and maintenance of the ovarian reserve, directly regulating follicle pool size, ovarian aging, and reproductive lifespan.

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