Transcriptional regulation by NR5A1 of theca cell marker genes in growing cultures. Bovine theca cells cultivated in the presence of 10 μg/ml insulin for maximal growth were infected with adenoviral vectors expressing bovine or murine wild-type NR5A1 (WT) or mutants lacking one of the two activating functions (ΔAF-2 or S203A, control: AdEasy adenoviral vector without insert). CYP11A1, STAR, and INSL3 transcripts were quantified by real time-PCR as described in Materials and Methods. The results of one representative out of three experiments are shown. Data are expressed as mean ± standard deviation. The groups designated by the letters above the bars differ significantly at the level of P < 0.05.