Gene silencing, cell fate and nuclear organisation.

Although advances in molecular biology have allowed us to identify and describe many of the events associated with turning genes on, much less attention has generally been focussed on the related process of gene silencing. This is surprising as heritable gene inactivation plays an important role in determining cell lineage fates during development and defining their temporal order. Recent advances in the area of chromatin and chromosome organisation may have an impact on our understanding of cellular differentiation.