Fig. 6.

The role of actomyosin contractility in tissue stiffness.(A) A transverse confocal section of F-actin labeled with bodipy-FL phalloidin shows that latrunculin B (latB) significantly reduces the amount of F-actin in the whole embryo. (B) Treatment of explants for 20 minutes with latB reduced tissue stiffness by up to 70% in a dose-dependent manner. The entire tissue dissociates at higher concentrations with treatments lasting more than 60 minutes. (C) Incubation of explants for 40 to 60 minutes in Y27632 reduced tissue stiffness up to 50% in a dose-dependent manner. (D) Combined treatment of explants cultured 40 to 60 minutes in Y27632 and 20 minutes in latB showed that explants cultured in Y27632 dropped in stiffness to the level of explants incubated in latB. Dose dependence of latB and Y27632 was carried out with embryos from three different clutches. Results from three clutches were scaled to the control stiffness and combined in the single chart shown. Whisker box bounds in B and C indicate 1st quartile, median and 3rd quartile. Error bars indicate standard deviations. ¹Control dorsal isolates treated with DMSO carrier were pooled in B and C. ^**P<0.05.