Fig. 5-S1

HH signaling during scale development.

(A) Epidermis (cldnb:EGFP, green) was folded around the bony scale plates (ARS, magenta) in larvae treated with 1% EtOH throughout squamation; n = 8. 40 µM cyclopamine treatment completely blocked epidermal folding, even when scale plates overlapped (arrow); n = 8. (B,C) Heatshock induction of dominant repressor Gli2 (hs:gli2-DR) strongly attenuated expression of the HH reporter transgene (gli2-D:mCherry; b) and the conserved HH target gene hhip (arrowheads in C). (D) shha expression was only detectable in the epidermis following formation of the scale papilla (papilla). Expression persisted in two to three rows of cells at the epidermal posterior margin in growing scales (extension). (E) The HH target gene, hhip, also initiated expression following papilla appearance (papilla) and persisted in a population of cells deep to the dermal scale forming cells (SFC). (F,G) shha and hhip expression was not detected in scales (arrowheads) following induction of hs:dkk1 (n = 8). Eda mutants (nkt/nkt) also lacked shha and hhip expression (n = 6). (H) hs:dkk1 induction attenuated expression of the HH reporter gli2-D:mCherry; n = 6. Scale bars, 100 µm (A, B, C, F, G); 50 µm (D, E, H).