Fig. 3. Chromatin decondensation in E7.5 transgenic embryos. (A) 3D DNA-FISH of: (left panel) Lnp and Hoxd, (middle panel) Hoxb1 and Hoxb9 probes on nuclei from the PS of E7.5 wild-type embryos, and of (right panel) Hoxb1-LacZ and Hoxd probes on nuclei from the PS of an E7.5 Hoxb1-LacZ embryo. Nuclei were counterstained with DAPI. Images are maximal projections of 3D stacks after deconvolution. (B) Distributions of mean-squared interphase distances (d² in µm²) normalised to genomic separation (in Mb) measured between the Hoxb1 and Hoxb9 probes (dark-grey bars) at endogenous Hoxb and between Lnp and Hoxd probes (white bars) at endogenous Hoxd in EEM and PS nuclei from E7.5 wild-type embryos, or between the Lnp and Hoxb1-LacZ probes (light-grey bars) and between the Hoxb1-LacZ and Hoxd probes (black bars) in EEM and PS nuclei from E7.5 Hoxb1-LacZ embryos.