Fig. 8. Exposure of explant cultures to d-tubocurare prevents expression of sMyHC2 but not of other MyHC genes. Explants of somites with the neural tube taken from HH 14 embryos were cultured for 24 hours in the presence (A-D) or absence (E) of 16 µM d-tubocurare and assayed by in situ hybridization with probes specific for sMyHC1, 2 and 3, and efast MyHC. (A) efast MyHC, (B) sMyHC1 and (C) sMyHC3 are expressed in the presence of dtubocurare. (D) sMyHC2 was not expressed in explants cultured in the presence of dtubocurare but (E) was expressed when cultured in its absence.