Two forms of X-chromosome inactivation ensure the selective silencing of female sex chromosomes in mouse embryos. Imprinted silencing begins with the detection of Xist RNA expression on the paternal X chromosome at about the four-cell stage of development. Later, a random form of inactivation silences either the paternal or the maternal X chromosome. Here it is shown that maternal deposits of the ubiquitin ligase Rnf12/RLIM are required for the imprinted form of X-chromosome inactivation.
- JongDae Shin
- Michael Bossenz
- Ingolf Bach
