Fig. 8

Characterization of the CR2 region. (A) ATAC-seq tracks showing accessibility profiles in the CR2 region. CR2 includes two peaks, a and b. Phylogenetic conservation data (phyloP) [80] is shown in dark blue. (B) Hi-C data from 3D genome browser [83] highlighting CR2 location in the same TAD as Nr2f2. (C-D’’) Comparison of Nr2f2 expression pattern in wild type embryos by in situ hybridization (C–C’’) with β-gal reporter expression in CR2-β-gal transgenic embryos (n = 4/5) (D-D’’). Expression is present in the hindbrain (arrows in C’’ and D’’) but absent from the spinal cord (arrows in C’ and D’). (E-E’’) β-gal reporter expression in CR2a-β-gal transgenic embryos (n = 3/6). Reporter expression is restricted to the second branchial arch (arrow in E), rhombomere 5 (arrow in E’’) and somites from the forelimb level. (F-F’’) β-gal reporter expression in CR2b-β-gal transgenic embryos is extended to the anterior somites and neural tube (n = 3/3) (arrow in F’). (G) schematic representation of generated transgenic reporters for CR2a and CR2 regions lacking the specified TF binding sites. (H–H’’) β-gal reporter expression in CR2a^∆MSGN1-β-gal transgenic embryos is limited to the second branchial arch (arrow in H), rhombomere 5 (arrow in H’’) (n = 3/3). (I-I’’) β-gal reporter expression in CR2a^∆HOX-β-gal transgenic embryos expands up to rhombomere 3 (arrow in I’’) and along the neural tube (arrowhead in I’’) (n = 6/7). (J-J’’) β-gal reporter expression in CR2^∆HOX-β-gal transgenic embryos is extended into the neural tube (arrows) (n = 3/5). (K) Whole-mount in situ hybridization of wild type, CR2a^∆/∆, CR2b^∆/∆ and CR2^∆/.^∆ at E9.5 using a probe for Nr2f2