Initiation of growth of baboon primordial follicles in vitro

Abstract

Factors that cause some primordial follicles to enter the growth phase while the others remain quiescent are unknown. The hypothesis was tested that primate primordial follicles can survive and initiate growth in vitro in serum-free medium. Superficial pieces of ovarian cortex, containing mostly primordial follicles, were obtained from baboon fetuses during late gestation and cultured for 0, 2, 4, 7, 10 or 20 days in Waymouth MB 752/1 medium supplemented with insulin, transferrin, selenium, linoleic acid, and bovine serum albumin (ITS +). Histological examination of cortical pieces revealed that after 2 and 4 days in culture, the total number of primordial follicles had decreased by 55 and 76% (P < 0.01) respectively, relative to day 0 of culture. This was associated with a sustained, 5- to 8-fold increase in total primary follicles (P < 0.01) beginning on day 2 of culture. There was also a gradual increase in the total number of early secondary and secondary follicles. The average diameter of follicles and oocytes increased gradually throughout culture for all follicular categories (P < 0.01), except secondary follicles and oocytes. Immunohistochemical localization of proliferating cell nuclear antigen (PCNA), a marker for cell proliferation and growth, showed that PCNA was generally absent in primordial follicles on day 0, but was observed after 2 or 4 days in culture in both granulosa cells and oocytes of most growing follicles. Comparison of cortical pieces cultured for 10 or 20 days with ITS + versus 10% fetal bovine serum (FBS) showed a more pronounced decrease in the numbers of primordial follicles and more primary, early secondary and secondary follicles in ITS + compared to FBS-treated cortical pieces (P < 0.01 at 20 days). These results show that primordial follicles from non-human primates can survive and develop to the secondary stage in vitro in serum-free conditions.

Disordered follicle development in ovaries of prenatally androgenized ewes

“…We found no major differences between androgenized and control ovaries when cortical tissue was cultured for up to 15 days. The proportion of growing follicles increased with time in culture in both types of ovary, a finding similar to our observations of cultured cortical biopsies from normal (Wright et al 1999) and polycystic human ovaries (Webber et al 2003) as well as reported studies in baboon (Wandji et al 1997) and cow (Wandji et al 1996). It was of interest that both progesterone and androstenedione were detected in conditioned medium from cultured biopsies of both types of ovary in these sheep studies (although there were no significant differences between the groups).…”

Blocking the PI3K pathway or the presence of high concentrations of EGF inhibits the spontaneous activation of ovine primordial follicles in vitro

“…When cortical pieces were placed in culture, primordial follicles would be released from the influence of inhibitor(s) of medullary origin (Cushman et al, 2002), or the stimulatory factor(s) would override the effect of inhibitor(s) (Braw-Tal, 2002), allowing follicle activation to be initiated spontaneously even in the control medium (Wandji et al, 1996b;Braw-Tal and Yossefi, 1997). Other possible explanation for the spontaneous activation is that the fragmentation step, i.e.…”

Light microscopical and ultrastructural characterization of goat preantral follicles

“…During the past few years the possible exploitation of preantral follicles from domestic animals, by isolation and culture, has received much attention , Jewgenow and Goritz, 1995, Nuttinck et al, 1996, Wandji et al, 1996, Lucci et al, 1999and Cecconi et al, 1999. However, in some studies, the results were not promising possibly due to follicle damage induced by the isolation procedures (Van den Hurk et al, 1997 and Katska and Rynska, 1998).…”