Fig. 5: Lamin-A regulates fate by controlling actin nucleator localization.

a, Formin 2 shows a high nuclear:cytoplasmic ratio, which is increased in outer cells following cell internalization. n = 4 for all stages. *P = 0.0286, Mann-Whitney U test. b, Knockdown of Lamin-A by siRNA reduces nuclear:cytoplasmic Formin 2. siRNA was microinjected at the 1-cell stage. Insets show reduced levels of Lamin-A in siRNA. n = 14 for control, n = 10 for Lamin-siRNA. *P = 0.0470, Mann-Whitney U test. c, Treatment with SMIFH2 reduces inner cell F-actin and increases nuclear:cytoplasmic Yap. 16-cell embryos were either treated with DMSO (control) or 250 µM SMIFH2 and immunostained for Yap and with phalloidin. Insets highlight the differences between inner cell cytoplasmic phalloidin intensity and nuclear Yap intensity between control and treated embryos. *P = 0.0364, **P = 0.0024, Mann-Whitney U test. d, e, Emerald-Formin 2 overexpression. Emerald-Formin 2 RNA was microinjected into a single cell of the 2-cell embryo, fixed at the 16-cell stage and immunostained for either Yap or Amot. Injected cells can be identified by Emerald-Formin 2 expression (arrowheads). Injected outer cells show increases in cytoplasmic phalloidin, nuclear Yap and cytoplasmic Amot intensities compared to uninjected cells. For panel (d) n = 10 for Emerald-Formin 2 (injected cells), n = 9 for control (uninjected cells). ***P = 0.0006, *P = 0.0244, Mann-Whitney U test. For panel (e) n = 9 for control (uninjected cells), n = 10 for Emerald-Formin 2 (injected cells). **P = 0.0063, *P = 0.0414, Mann-Whitney U test. Fluorescence intensities represent results standardized to DAPI. Bars in dot plots represent median and interquartile range. All statistical tests are two-tailed. Scale bars, 10 µm. Source data are provided as a Source Data file.