Identification of the Chromatin Regions Coated by Non-coding Xist RNA

Xist non-coding RNA (ncRNA) is essential for X chromosome inactivation (XCI). Some genes can escape from XCI, but how this occurs is unknown. We developed a modified RNA tagging and recovery of associated proteins ( TRAP) method to study the association between Xist RNA and its target genes. In mouse cells, Xist RNA was detected on the Uba1 gene, but not on Jarid1c and Utx genes, which escape from XCI. Using this technique we were able to show that the Xist RNA molecule is not present on active genes that escape from XCI, but is present on genes inactivated by XCI, suggesting that this method is a powerful tool for functional analysis of ncRNA. Copyright (C) 2009 S. Karger AG, Basel