Effect of Fibroblast Co-culture on In Vitro Maturation and Fertilization of Mouse Preantral Follicles

BACKGROUND: The aim of this study was to evaluate fibroblast co-culture on in vitro maturation and fertilization of prepubertal mouse preantral follicles. MATERIALS AND METHODS: The ovaries of 12-14 day old mice were dissected and 120-150 μm intact preantral follicles with one or two layers of granulosa cells, and round oocytes were cultured individually in α-minimal essential medium (α-MEM) supplemented with 5% fetal bovine serum (FBS), 100 mIU/ml recombinant follicle stimulating hormone, 1% insulin, transferrin, selenium mix, 100 μg/ml penicillin and 50 μg/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. RESULTS: 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. CONCLUSION: Fibroblast co-culture increased survival rate and steroid production of preantral follicles by promoting granulosa cell proliferation.