Effects of gonadotrophins, growth hormone, and activin A on enzymatically isolated follicle growth, oocyte chromatin organization, and steroid secretion.
So far, standard follicle culture systems can produce blastocyst from less than 40% of the in vitro matured oocytes compared to over 70% in the in vivo counterpart. Because the capacity for embryonic development is strictly associated with the terminal stage of oocyte growth, the nuclear maturity status of the in vitro grown oocyte was the subject of this study. Mouse early preantral follicles (100-130 microm) and early antral follicles (170-200 microm) isolated enzymatically were cultured for 12 and 4 days, respectively, in a collagen-free dish. The serum-based media were supplemented with either 100 mIU/ml FSH (FSH only); 100 mIU/ml FSH + 10 mIU/ml LH (FSH-LH); 100 mIU/ml FSH + 1 mIU/ml GH (FSH-GH) or 100 mIU/ml FSH + 100 ng/ml activin A (FSH-AA). Follicle survival was highest in follicle stimulating hormone (FSH)-AA group in both cultured preantral (91.8%) and antral follicles (82.7%). Survival rates in the other groups ranged between 48% (FSH only, preantral follicle culture) and 78.7% (FSH only, antral follicle culture). Estradiol and progesterone were undetectable in medium lacking gonadotrophins while AA supplementation in synergy with FSH caused increased estradiol secretion and a simultaneously lowered progesterone secretion. Chromatin configuration of oocytes from surviving follicles at the end of culture revealed that there were twice more developmentally incompetent non-surrounded nucleolus (NSN) oocytes (>65%) than the competent surrounded nucleolus (SN) oocytes (<34%). We conclude that the present standard follicle culture system does not produce optimum proportion of developmentally competent oocytes.
Ola
Safiriyu Idowu
SI
State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Ai
Jun-Shu
JS
Liu
Jing-He
JH
Wang
Qiang
Q
Wang
Zhen-Bo
ZB
Chen
Da-Yuan
DY
Sun
Qing-Yuan
QY
D028341:Activins / Q000494:pharmacology; D000818:Animals; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D002843:Chromatin / Q000648:ultrastructure; D003470:Culture Media / Q000378:metabolism / Q000494:pharmacology; D004798:Enzymes / Q000737:chemistry; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006062:Gonadotropins / Q000494:pharmacology*; D013006:Growth Hormone / Q000494:pharmacology; D051379:Mice; D009865:Oocytes / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D006080:Ovarian Follicle / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure
D002843:Chromatin; D003470:Culture Media; D004798:Enzymes; D012739:Gonadal Steroid Hormones; D006062:Gonadotropins; C422405:activin A; D028341:Activins; D005640:Follicle Stimulating Hormone; D013006:Growth Hormone