127. PUMA MEDIATES GERM CELL DEATH DURING OVARIAN DEVELOPMENT AND DETERMINES INITIAL PRIMORDIAL FOLLICLE NUMBER IN MICE
F. Morgan A B , K. J. Hutt A , C. L. Scott C D , M. Cook C , A. Strasser C D , J. K. Findlay A and J. B. Kerr BA Ovarian Biology Lab, Prince Henry’s Institute, Clayton, VIC, Australia.
B Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC, Australia.
C The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.
D Department of Medical Biology, Melbourne University, Parkville, VIC, Australia.
Reproduction, Fertility and Development 22(9) 45-45 https://doi.org/10.1071/SRB10Abs127
Published: 6 September 2010
Abstract
The proteins that control the number of primordial follicles initially established within the ovary are largely unknown. Here we investigated the hypothesis that PUMA, a pro-apoptotic protein belonging to the Bcl-2 family, regulates germ cell death during ovarian development and thereby determines the number of primordial follicles that make up the ovarian reserve. Ovaries were obtained from embryonic day 17.5 (E17.5) and post-natal day 10 (PN10) wild-type (wt) and puma–/– mice and subjected to morphological, molecular and stereological characterisation (n = 3-6 mice/genotype/age). At E17.5, ovaries were densely populated with germ cells and early meiotic oocytes. Immunostaining for MVH and PCNA confirmed the identity of germ cells and proliferating germ cells, respectively. Pyknotic nuclei and TUNEL positive germ cells were rarely detected, suggesting that cell death was uncommon at this age. At PN10, primordial follicle assembly was complete for both genotypes, as confirmed morphologically and by immunostaining for oocyte markers GCNA and MSY2. The number of germ cells in E17.5 wt and puma–/– ovaries was comparable (p=0.81, See Table 1). However, PN10 puma–/– ovaries contained significantly more primordial follicles than wt ovaries (P < 0.001, See Table 1), revealing an over-endowment of primordial follicles in the absence of PUMA. These data show that PUMA regulates the developmentally programmed death of germ cells between E17.5 and PN10 in the mouse and thereby determines the number of primordial follicles that make up the initial ovarian reserve.
This work was supported by the NHMRC (Program Grants #494802 and #257502, Fellowships JKF (#441101), KJH (#494836), CLS (#406675), AS (#461299)); the Leukemia and Lymphoma Society (New York; SCOR grant#7015), the National Cancer Institute (NIH, US; CA80188 and CA43540) and Victorian Government Infrastructure Funds.
