Time-lapse confocal imaging of gastrula-stage Xenopus embryo illustrates the increased frequency of Rho flares (mCherry-2xrGBD, grayscale) in embryos treated with 12.5 µM GsMTx4 (green arrowheads) compared with vehicle control (yellow arrows). Dividing cells are marked by cyan asterisks. Time interval, 21 s; video frame rate, 20 fps. Related to Fig. 7 C.