DNA methylation dynamics of oocyte in follicular maturation (ChIP-Seq data set)

Folliculogenesis in mammals is a cyclic and hierarchical process that the ovarian follicles undergo dramatic changes in the shape and number of granulosa cells accompanied by gradually enlarged immature oocyte. Here we show a thorough and high-resolution view of DNA methylation maps in oocyte free of somatic cells present at each distinct follicular development stages. We found that global DNA establishment occurs in Type5b follicles, the final stage of pre-antral follicles, and that the acquisition of DNA methylation at different trans-regulatory elements couples with different chromatin modifiers. Besides, we showed that Dnmt1 as well as Uhrf1 also play critical roles in requiring and retaining of de novo methylation statue, typically at LINE and LTR elements, in these immature oocytes, which successfully escape DNA replication. Our study thus refined the current knowledge on the establishment of unique DNA methylation profile in mammalian oocytes, and provide a valuable resource for further studies on female gametogenesis. We collected oocytes from detailed 9 stages of folliculogenesis stages and conduct NChIP-seq , each stage contains 1-2 replicates.