Fig. 7

Fig. 7 Disruption of actin microfilaments leads to loss of scl expression in the RBI. Dechorinated embryos at tailbud stage were exposed to cytochalasin B (4 μg/ml) or latrunculin B (0.25 μg/ml) and fixed at 5–6 somite stage for whole-mount in situ hybridization using the ,scl gene probe. 30–40% Mortality was observed in all drug exposures due to rupture of the enveloping layer at variable times. Dead embryos were not analyzed further. Flat mounts of representative embryos from cytochalasin B exposure (A–C; normal, posterior expression only, no expression) and DMSO control (D) were prepared to show the anterior and posterior expression of scl. (E) Data were summarized from four independent experiments which show that the majority of embryos specifically lost the anterior scl expression after drug treatments. Posterior-specific loss of expression was never observed.