Figure 2.

Timing of the acquisition of competence to undergo expansion in vitro. Complexes were cultured in control medium or medium supplemented with a low concentration of FSH (0.005 IU/ml) for 2, 4, 6, 8 and 10 days. Following the culture period, complexes were cultured in control medium or medium with EGF (10 ng/ml) for 15 hours during the test period to stimulate cumulus expansion. (+) indicate positive expansion, (−) negative expansion and (+/−) mixed response.