Fig. 1

Quantification of Germinal Vesicle Breakdown during In Vitro Maturation. Cumulus-oocyte-complexes (COCs) were aspirated from 2 to 4 mm follicles and allowed to undergo in vitro maturation (IVM). a Representative images indicating how oocytes were scored as containing an intact germinal vesicle (GV) or undergoing or have undergone germinal vesicle breakdown (GVBD). White scale bars represent 25 μm. b COCs were collected from IVM at 8-h intervals, denuded, fixed, and the chromatin was stained with DAPI. GVBD increased rapidly from 8 to 24 h of IVM, where by 24 h of IVM approximately 75% of the oocytes collected were scored as GVBD. c Vehicle control, 0.5 mM, 1.0 mM, or 2.0 mM IBMX was added to IVM media, and oocytes were collected at 0, 24, and 42 h of IVM to be scored at either GV-intact or having undergone GVBD. All three concentrations of IBMX inhibited GVBD. Asterisks denote significant difference (P < 0.05)