A chemical screen in zebrafish embryonic cells establishes that Akt activation is required for neural crest development [RNA-seq]

The neural crest is a dynamic progenitor cell population that arises at the border of neural and non-neural ectoderm. The inductive roles of FGF, Wnt, and BMP at the neural plate border are well established, but the signals required for subsequent neural crest development remain poorly characterized. Here, we conducted a screen in primary zebrafish embryo cultures for chemicals that decrease neural crest formation, as read out by crestin:EGFP expression. We found that the natural product caffeic acid phenethyl ester (CAPE) disrupts neural crest gene expression, migration, and melanocytic differentiation by reducing Sox10 activity. CAPE inhibits PI3K/Akt signaling specifically in FGF-stimulated cells, and neural crest defects in CAPE-treated embryos are suppressed by constitutively active Akt1. Inhibition of Akt activity by constitutively active PTEN similarly decreases crestin expression and Sox10 activity. Our study has identified Akt as a novel intracellular pathway required for neural crest development. Overall design: To evaluate the effect of CAPE on gene expression in zebrafish neural crest cells, we treated sox10:GFP transgenic embryos with 10 micromolar CAPE or DMSO control at 2 ss, then sorted GFP+ cells at 17 ss for analysis by RNA-seq.

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