In vitro culture of rat pre-antral follicles with emphasis on follicular interactions.
The present study was designed to determine whether rat pre-antral follicles can grow under in-vitro conditions. Emphasis is on whether follicular interaction is involved in in-vitro follicle culture, and furthermore its role in follicular development has been assessed. Pre-antral follicles were isolated mechanically from 10-day old rat ovaries. They were divided into small (50 microm < diameter < 100 microm) and large (120 microm < diameter < 200 microm) pre-antral follicles and cultured individually or in groups for 6 days in medium with or without fetal calf serum (FCS). Based on morphological criteria, large pre-antral follicles cultured in groups in serum-free medium had significantly higher survival rates than those cultured individually. In the presence of FCS, no significant difference was detected with respect to the survival. However, the large pre-antral follicles cultured in groups had a significantly greater increase in diameter than those cultured individually. Furthermore, follicles cultured in groups in FCS-containing medium exhibited significantly more follicular cell proliferation than those in serum-free medium, based on DNA measurement. The present culture system (with or without FCS) proved to be insufficient for small pre-antral follicles to stimulate growth comparable to that of large pre-antral follicles. The transmission electron microscopical (TEM) study revealed the ultrastructural differences between follicles cultured in FCS-containing and serum-free media. Taken together, the results suggest that interfollicular factors are involved in follicle development in vitro, which especially at the early folliculogenesis stage plays a positive role in terms of follicular growth as well as survival. The present culture model allows further investigation of factors that regulate early folliculogenesis.
Zhao
J
J
Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Dorland
M
M
Taverne
M A
MA
Van Der Weijden
G C
GC
Bevers
M M
MM
Van Den Hurk
R
R
D000818:Animals; D002450:Cell Communication; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division; D002470:Cell Survival; D016895:Culture Media, Serum-Free / Q000378:metabolism; D005260:Female; D006107:Granulosa Cells / Q000502:physiology / Q000648:ultrastructure; D008854:Microscopy, Electron; D009865:Oocytes / Q000502:physiology / Q000648:ultrastructure; D009924:Organ Culture Techniques; D006080:Ovarian Follicle / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D013799:Theca Cells / Q000502:physiology / Q000648:ultrastructure; D013997:Time Factors
D016895:Culture Media, Serum-Free