Fig. 4-S1

Fgfr signaling blockade, expression and persistence after Wnt/β-catenin signaling inhibition.

(A) Scales added over the course of a five day treatment with 0.1% DMSO or 1 µM BGJ398. DMSO-treated fish added more scales then BGJ398-treated fish (p=0.0001). (B) Scale surface area increased more in DMSO-treated controls than BGJ398-treated fish (p<0.0001). (C) Standard length increased similarly in DMSO treated fish and BGJ398-treated fish (p=0.15); n = 8 for all measurements. Plots indicate means ± SD. (D) fgfr1a was expressed broadly in epidermis prior to scale formation (pre-scale). Expression shifted to scale forming cells in the dermal papilla (papilla), and was maintained in scale forming cells at the posterior margin (extension). (E) Wnt repression following scale formation did not affect fgfr1a expression (late hs:dkk1), however, repression prior to scale formation prevented localized expression (early hs:dkk1). Eda mutants (nkt/nkt) did not show patterned fgfr1a expression. Expression was maintained in neuromasts (nm) of early hs:dkk1 and nkt/nkt. (F) fgfr2 was also detected broadly in the epidermis prior to scale formation (pre-scale), before become restricted to the epidermal posterior margin (papilla), where it was maintained throughout scale development (extension). (G) Similar to fgfr1a, fgfr2 expression was not affected by Wnt repression after scale formation (late hs:dkk1), although patterned expression was blocked by Wnt repression prior to scale formation (early hs:dkk1) and also by loss of Eda (nkt/nkt). n = 6 for all in situ hybridizations. ep = epidermis; d = dermis. Scale bars, 250 µm (D,F upper); (50 µm, D,F lower).