The chromatin accessibility landscape of mouse oocytes during configuration transition

The transition of chromatin configuration in mammalian oocytes from a non-surrounded nucleolus (NSN) to a surrounded nucleolus (SN) is critical for acquiring the developmental competence. However, the genomic and epigenomic features underlying this process remain poorly understood. In the present study, we first establish the chromatin accessibility landscape of mouse oocyte from NSN to SN stage. Through the integrative analysis of multi-omics, we find that establishment of DNA methylation in oocytes is independent on the dynamics of chromatin accessibility. In contrast, histone H3K4me3 status is closely associated with the dynamics of accessible-regions during configuration transition. Furthermore, by focusing on the actively transcribed genes in NSN and SN oocytes, we discover that chromatin accessibility coupled with histone methylation (H3K4me3 and H3K27me3) participates in the transcriptional control during phase transition. In sum, our data serve as a broad resource for probing configuration transition in oocytes, and provide the potential evidence to elucidate the mechanism determining chromatin dynamics and oocyte quality. Overall design: chromatin accessibility by high throughput sequencing