Colinearity loops out

Modulation of chromatin structure has long been proposed to underlie the colinear regulation of Hox genes during animal development. In a recent paper, Chambeyron and Bickmore explore this possibility in retinoic acid-induced ES cells. They show that, while chromatin remodeling confers transcriptional competence to the gene cluster, subsequent sequential extrusion of genes from their chromosome territory may determine their coordinated expression in time