Time-course expression profile of genes involved in cumulus expansion. COCs were isolated from WT and RIP140 knockout (KO) mice primed with eCG for 48 h and cultured for 4, 8, and 16 h with either 100 ng/ml AREG (A) or 300 ng/ml AREG (B). RNA was isolated from the cultured COCs, and the expression of genes assessed using Q-PCR. Expression of all analyzed genes was induced in WT COCs by 100 ng/ml AREG in a time course. In contrast, 100 ng/ml AREG failed to induce the expression of these genes in the KO COCs. The expression of Ptgs2, Has2, Tnfαip6, and Ptx3 was remarkably induced in the KO COCs cultured with 300 ng/ml AREG with impaired induction of Areg and Ereg. Most treatment groups represent up to four independent experiments containing pools of eight to ten COCs.