Fig. 2: Targeted recombination of the II1 transgene into T-DOM.
From: Context-dependent enhancer function revealed by targeted inter-TAD relocation
a Scheme of the HoxD locus with the triangles indicating the extent of both the C-DOM (green) and T-DOM (orange) TADs. Enhancers are green (distal limbs) or orange (proximal limbs) rectangles and the HoxD cluster is boxed. The arcing arrow on top indicates the origin and new location of the island II enhancer transgene into T-DOM. Below is a map of the II1:HHB:LacZ construct containing left (L-HA) and right (R-HA) homology arms, the II1 enhancer element, and the HBB promoter with a LacZ reporter gene. b B-galactosidase staining time course and LacZ mRNA (right panel) of the single-copy II1 T-DOM 542 founder line. At E10.5 and 11.5, staining is strong in the proximal limb (white arrow) while absent in the distal portion (black arrow). By E12.5 weak staining appears in the digit mesenchyme of the distal limb. The WISH for LacZ mRNA confirms that distal limb staining comes from transcription in distal limb cells rather than from stable B-galactosidase activity. c B-galactosidase staining in the multi-copy II1 T-DOM 320 founder line is stronger and more distal, except at the earliest time point where it is more similar to line 542. Black scales bars are 0.5 mm.
