The role of Xist in X-inactivation.

The past year has seen important progress in our understanding of the role of the X inactive specific transcript gene (Xist) in the initiation and propagation of X-inactivation. A 35 kb Xist transgene had been shown to recapitulate the functions of the X-inactivation centre, progress has been made towards indentifying factors controlling the randomness of X-inactivation, and RNA stabilisation has been shown to play a role in Xist regulation at the onset of X-inactivation.