X-chromosome inactivation is one of the most complex events observed in early embryo developments. The epigenetic changes occurred in female X-chromosome is essential to compensate dosages of X-linked genes between males and females. Because of the relevance of the epigenetic process to the normal embryo developments and stem cell studies, X-chromosome inactivation has been focused intensively for last 10 years. Initiation and regulation of the process is managed by diverse factors. Especially, proteins and non-coding RNAs encoded in X-chromosome inactivation center, and a couple of transcription factors have been reported to regulate the event. In this review, we introduce the reported factors, and how they regulate epigenetic inactivation of X-chromosomes.

• Jae Yeon Hwang(Department of Agricultural Biotechnology, Animal Biotechnology Major, Seoul National University,2Department of Cellular and Molecular Physiology, Yale School of Medicine)
• Chang-Kyu Lee(Department of Agricultural Biotechnology, Animal Biotechnology Major, Seoul National University) Corresponding author