Embryonic genome activation (EGA) is a highly complex phenomenon that is controlled at various levels. New studies have ascertained some molecular mechanisms that control EGA in several species; it is apparent that these same mechanisms regulate EGA in all species. Protein phosphorylation, DNA methylation and histone modification regulate transcriptional activities, and mechanisms such as ubiquitination, SUMOylation and microRNAs post-tran-scriptionally regulate development. Each of these regulations is highly dynamic in the early embryo. A better under-standing of these regulatory strategies can provide the possibility to improve the reproductive properties in mammals such as pigs, to develop methods of generating high-quality embryos in vitro, and to find markers for selecting de-velopmentally competent embryos.

• Reza K. Oqani(Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University)
• Jung Won Kang(Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University)
• Tao Lin(Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University)
• Jae Eun Lee(Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University)
• Dong-Il Jin(Department of Animal Science & Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University) Corresponding author