Fig. 1
From: In vivo Hox binding specificity revealed by systematic changes to a single cis regulatory module
Hox regulatory inputs in vvl1+2 CRM. a–c Spatial relation of vvl1+2 expression pattern (red) with respect to various Hox expression domains. a Labial (purple) is expressed in the intercalary segment, (b) Dfd (blue) is expressed in the mandible and maxilla, (c) Ubx and Abd-A (green) protein expression extends from T3 to A7. d–i In silico predicted relative affinity and localisation of Hox binding sites for Lab-Exd (d), Dfd-Exd (e), Ubx IVa-Exd (f), Lab monomer (g), Dfd monomer (h) or Ubx IVa isoform monomer (i) in vvl1+2. (j) Scheme of vvl1+2 and the S1, S2 and S3 sub-fragments showing the localisation of the main (blue) and overlapping (red) Hox-Exd sites. (k) Scheme of a canonical Hox-Exd binding site showing the central core bound by both proteins (grey), the Exd (pink) or Hox (yellow) bound flanking sites, and the core sequences bound preferentially by class 1, 2 and 3 complexes. Expression of vvl1+2 in wild type (l) or hthP2 embryos effectively behaving as Exd mutants (m). Expression of the S1+S2 fragment (n) or S2 (o) in wild type embryos. p Scheme showing the S1 and S1+55 constructs. a–c highlight the segments where each Hox protein is expressed: Lab in the intercalary (ic); Dfd in the mandible (md) and maxilla (mx); Scr in the labium (lb) and the first thoracic (T1). Antp, Ubx, Abd-A and Abd-B are expressed in the (T1-A9) thoracic (T) and abdominal (A) trunk segments (only Ubx and Abd-A expression are shown in c). Embryos in a–c were expressing UAS-lacZ with the arm-Gal4 line to label all cells in grey. In panels d-i the coloured horizontal bar represents the extension of the S1 (grey), S2 (green), and S3 (orange) sequences. Scale bar 50 μm
