Fig. 1

Dynamics of actomyosin and Pard6 polarisation at the 8-cell stage. a Mouse embryos were fixed at early, mid and late 8-cell stage, and immunostained for F-actin and Pard6. Arrowheads indicate the magnified blastomeres. b Circumferential line profiles of F-actin and Pard6 fluorescence intensity in embryos from (a). Yellow indicates cell–cell contact regions and blue cell-contact-free domain. Smoothened data were displayed as coloured curves to show the pattern of the signal. c Cell-contact-free enrichment of F-actin and Pard6 plotted against the IEA in embryos from (a). Each dot represents an individual measurement. N = 25 embryos, three independent experiments. LOWESS plot were used to display the tendency of different datasets. The shadow indicates the 95% confidence interval. d Summary of the different phases of polarisation during the 8-cell stage. During the first phase, embryos start compacting and actomyosin becomes polarised to the apical domain. During the second phase, embryos are already compacted and apical domain components, including Pard6 polarise apically. All scale bars, 15 μm