RESUMO
The aim of this study was to evaluate fibroblast co-culture in vitro maturation and fertilization of prepubertal mouse preantral follicles. The ovaries of 12-14 day old mice were dissected and 120-150 micro m intact preantral follicles with one or two layers of granulose cells, and round oocytes were cultured individually in alpha-minimal essential medium [alpha-MEM] supplemented with 5% fetal bovine serum [FBS], 100 mIU/ml recombinant follicle stimulating hormone, 1% insulin, transferring, selenium mix, 100 micro g/ml penicillin and 50 micro g/ml streptomycin as base medium for 12 days. A total number of 226 follicules were cultured under two conditions: i] base medium as control group [n=113]; ii] base medium co-cultured with mouse embryonic fibroblast [MEF] [n=113]. Follicular diameters, alone, in addition, to other factors were analyzed by student's t-test and chi-square test, respectively. The co-culture group showed significant differences [p<0.05] in growth rate [days 4, 6 and 8 of the culture period] and survival rate. However, there was no significant difference in antrum formation, ovulation rate and embryonic development of released oocytes. There were significant differences [p<0.05] in the estradiol and progesterone secretion at all days between the co-culture and control groups. Fibroblast co-culture increased survival rate and steroid production of preantral follicles by promoting granulose cell proliferation