Figure 6

Functional testing of transcription factors implicated in sox10 regulation. A, B. Early zebrafish embryos (6 hpf), injected with plasmid constructs at the 1-cell stage, were divided and half subjected to a 60 minute 37°C heatshock. All were left to develop for a further 1 hour at 28.5°C before fixing. sox10 in situ hybridisation was performed to assess ectopic sox10 expression. A, A' embryos injected with Hs:notch^ΔEmv. B, B' embryos injected with Hs:Δβ catenin. C. Embryos of the transgenic line Tg(-4725sox10:GFP)^ba3 were injected with equivalent constructs lacking GFP-coding regions. C, C' embryos injected with hs:zsox9b. A-C no heatshock, A'-C' with heatshock. Ectopic sox10 or gfp expression is indicated by the coloured reaction product (arrows). Note that the low level expression in B reflects the known leakiness of this heatshock promoter [71].