chromatin regulation in different cell types using a mouse with an indicator and an array of regulatory sites knocked into the Oct4 gene (113). This system allows one to study the dynamic behavior of the locus, the rate of heterochromatin propagation, the dissolution and assembly of heterochromatin, and the in vivo synergy with other chromatin modifiers (114) in any tissue of the developing or adult animal. Understanding the dynamics and mechanisms underlying BAF-polycomb opposition might also be fruitfully approached with this system (Kadoch et al., unpublished results).
