Fig. 3

Myosin1 proteins regulate spaw expression independently of the LRO flow. a, b Quantification of spaw extension in the Left (green dots) and Right (red dots) LPM of 18 somites stage LRO flow-deficient dnaaf1 morphant (a) or dnaaf1 mutant (b) embryos. myo1d/g loss of function causes a significant reduction of the antero-posterior extension of spaw expression in both the Left and the Right LPM. To allow direct comparison, mutant animals in a, b are derived from the same genetic background. Box plots in a, b indicate mean values ± SD. c, c′ Double in situ hybridization for spaw and the cardiac marker cmlc2/myl7 (see Supplementary Fig. 5 for pictures) reveals that spaw expression reaches the cardiac primordium in most WT control and LRO flow-deficient dnaaf1 morphant (c) or dnaaf1 mutant (c′) embryos, but fails to do so upon inactivation of myo1g. All p values were obtained using non-directional statistical tests. Complete numerical and statistical information for all experiments are provided in the Source Data files.