Deciphering the human genome sequence has provided critical insight in genome function in relation to biological processes in health and diseases. Recent technological improvements have opened up the analysis of the epigenetic regulation of the information embedded in the genome. Epigenetic regulation takes place at many levels including histone modifications, positioning of histone variants, nucleosome remodeling and DNA accessibility. Together with DNA modifications, transcription factors and other DNA-binding proteins this information provides an epigenetic blueprint. The epigenetic features of each cell type in the body (>250) are distinct and once established during development and differentiation need to be maintained. Hence, the study of epigenetic processes go beyond DNA-stored information and provide essential insight in the manual of the genome, in deciphering derailed processes in disease.
I will discuss the mechanism involved in DNA deposition and removal during the transition of 2i to serum states of embryonic stem cells (ESCs). Collectively, our epigenome, transcriptome and DNA methylomes data show that 2i cells reflect preimplantation ICM cells (stage E3.5) whereas serum ESCs that of post-implantation stage E6.5.