Chromatin conformation of the Shh locus in limbs.. Chromatin conformation of the Shh locus in limbs.

Expression of Shh in the limb is dependent on a distant enhancer located 850kb away from the gene promoter. We performed chromatin conformation capture (4C-Seq) analysis of the Shh locus in E11.5 mouse limbs so as to better understand the relationship between this regulatory interaction and the structural organisation of the locus. The experiments were performed on wild-type animals as well as on animals carrying an engineered chromosomal inversion (INV(6-C2) (INV6)) . The different viewpoints used (Shh, ZRS, Nom1, Rbm33, Rnf32) enable to characterize the 3D organisation of the locus in the different contexts. The inversion INV6 disrupts the normal topological organisation of the Shh locus in a compact 3D-domain and prevents the physical and regulatory interaction between Shh and its limb enhancer, even though the genomic distance separating the two elements is reduced compared to WT.