Fig.4.

Histone modifications of the promoters of StAR and Cyp19a1 in granulosa cells undergoing luteinization during ovulation. Granulosa cells were obtained from rats treated with equine chorionic gonadotropin before (0 hours) and 4 hours, and 12 hours after human chorionic gonadotropin injection. For histone modifications, histone-H4 acetylation (AcH4), trimethyl histone H3K4 (H3K4me3), trimethyl histone H3K9 (H3K9me3) and trimethyl histone H3K27 (H3K27me3) were analyzed by chromatin immunoprecipitation assay in each region of the StAR promoter (proximal region 1, proximal region 2, and distal region) and the Cyp19a1 promoter (Fig. 3). The data of the proximal region-1 of the StAR promoter are shown. AcH4 and H3K4me3 activate transcription while H3K9me3 and H3K27me3 inactivate transcription. Data were expressed as a ratio of the value of 0 hours. Values are mean±SEM of more than three independent experiments. ^a)P<0.05 versus 0 hours. The data were reported in the reference no. 15.