Figure 8. Proposed model for the epigenetic regulation of prophase I chromosome activity.

The histone demethylase dKDM5 programs the oocyte chromatin state during early oogenesis, through its actions on H3K4me3 and other epigenetic modifications such as H3K9ac. Once programmed, the dKDM5-dependent oocyte epigenome temporally controls, several hours afterwards in late prophase I, the onset of transcription and meiotic chromosome remodeling. Ultimately, the germ line-specific activity of dKDM5 is required for successful completion of meiosis and female fertility. Development time in relation to the start of oogenesis is expressed in hours post-germ line stem cell division (h.p.d.).