Progress in roles of epigenetic modifications in regulating embryonic development

Epigenetic modifications,a class of ubiquitous gene regulation patterns e.g.gametogenesis and embryonic development,are crucial for activities of living mammals.DNA methylation,histone acetylation and histone methylation are three main forms of epigenetic modifications.Generally,they coordinately regulate gene expression and are readily affected by multiple environmental factors,such as nutrition and xenobiotics.Moreover,they play important roles in embryonic development.Many embryonic even adult diseases may be due to abnormal epigenetic modifications during embryogenesis.The potential clinical significance of DNA methylation,histone acetylation and histone methylation on gene expression and embryonic development is reviewed.