PARENT SESSION
SLIDE SESSION 2: FACTORS REGULATING EARLY FOLLICULAR DEVELOPMENT
Chairs: Evelyn Telfer, Robert Koos, Leanne Sleer (Trainee)
Univ Ottawa-UCU Auditorium
2:30 PM-4:30 PM

A ROLE FOR PLATELET DERIVED GROWTH FACTOR RECEPTOR IN THE DEVELOPMENTAL ORGANIZATION OF THE MOUSE OVARY.

Sleer, Leanne¹, Taylor, Christopher¹, ¹

ABSTRACT- We have previously identified the presence of platelet derived growth factor receptor beta (PDGFR-) throughout thecal and stromal compartments of the adult porcine ovary as well as in oocytes of perinatal rat ovaries. This study was conducted to further elucidate the developmental expression pattern of PDGFR- and to identify a function of the receptor in the developing mouse ovary. Immunohistochemical studies show the receptor to be present in thecal and interstitial cells in ovaries from mice from day 8 to day 28. In ovaries from mice at day 0 (birth) to day 4, PDGFR- is present in somatic cells surrounding oocytes. Surprisingly, at all ages studied (day 0 - 28), PDGFR- is also present in the nucleus of oocytes of primordial, primary and secondary follicles. To determine a role for the receptor in the developing ovary, we have utilized mice with a targeted disruption of the PDGFR-. These mice die perinatally due to abnormal kidney development and fatal hemorrhages. Ovaries from PDGFR- null mice at day 0 lack an organized structure and have a slightly elevated level of apoptosis in comparison to ovaries from day 0 wild type mice. Culture of day 0 wild type ovaries for several days results in some follicular development. In contrast, culture of PDGFR- null ovaries results in impaired follicular development and a significant increase in apoptosis. These data reveal a novel and critical role for PDGFR- in the development and structural organization of the ovary, as well as in maintaining cell survival.

KEY WORDS: platelet derived growth factor receptor, ovary, theca, oocyte