Fig. 5

Misexpression of Hes1 at the neural crest (NC) stage inhibits G1/S transition and NC emigration. a–b’ Co-electroporation of the dorsal neural tube (NT) at the NC (17 ss) or RP (40 ss) stages, respectively, with control RFP (red) and a Hes1 reporter-GFP. Ten hours later, Hes activity is apparent in RFP+ cells only at the roof plate (RP) stage (b, b’). c–j Hemi-NT electroporations of control GFP or Hes1 at the NC stage, analyzed 16 h (i, j), 24 h (c–f), or 48 h (g, h) after transfection. Dorsal views of whole embryos (c, d) and sections stained for the migrating NC marker HNK-1 (e–h) showing the absence of migrating Hes1+ cells in d, f, and h compared to GFP+ controls in c, e, and g. i, j A BrdU incorporation assay (1-h incubation) showing reduced incorporation in the dorsal NT of embryos electroporated with Hes1 compared to GFP controls. Nuclei are visualized with Hoechst (blue). Dashed lines delimit the analyzed dorsal NT domain. k Quantification of the mean percentages ± standard error of the mean of BrdU+ cells in the dorsal NT (*P < 0.01). Bar in b, e, f = 50 μM; g, h =70 μM; a, i–j” = 40 μM