Fig. 4. Expression of various limb patterning genes in chelerythrine chloride-treated wing buds. Embryos treated with chelerythrine chloride were analyzed for gene expression at the stage indicated. Green asterisks mark the slow release beads and yellow arrows point to the normal expression in untreated buds. (A,B) Shh transcripts were never detected in the treated bud. (C) Fgf4 expression in the AER of the treated wing bud (red arrow) has lost its posterior bias. (D) At stage 18, Fgf10 expression was not markedly different between the treated (red arrow) and the contralateral wing bud. (E) At stage 19, Fgf10 expression in the treated wing (red arrow) was downregulated. (F) By stage 24, Fgf10 mRNA was not detectable in the treated bud. In the embryo shown in G, the level of Fgf8 expression in the AER of the treated wing bud is reduced. By contrast in H, Fgf8 expression in the AER was not affected. (I) Msx-1 expression (red arrow). (J) The size of Rel/NF-
B expression domain (red arrow) was reduced in the treated wing bud.
