Live Imaging of C. elegans Embryos

Live imaging of one- or four-cell C. elegans embryos was performed under no compression at 23°C. Adult hermaphrodites were dissected in M9 buffer (86 mM NaCl, 42 mM Na₂HPO₄, 22 mM KH₂PO₄, and 1 mM MgSO₄.7H₂O), and embryos were placed in the wells of imaging chambers as shown in Fig. 4 B (Carvalho et al., 2011 (link)). In the experiments with latrunculin A (Sigma-Aldrich) or propidium iodide, adult hermaphrodites were dissected in meiosis medium (25 mM Hepes, pH 7.4, 5 mg/ml insulin, 20% heat-inactivated FBS, and 60% Leibowitz-15 medium; see Acute drug treatment method section for details). Images were acquired with a spinning-disk confocal system with a CSU-X1 confocal spinning-disk head (Yokogawa Electric Corporation) mounted on an inverted microscope (TE2000U; Nikon) equipped with an electron-multiplying charge-coupled device camera (iXon 897+; Andor Technology), a 100× 1.4 NA oil-immersion Plan-Apochromat objective (Nikon), and 488-nm and 561-nm lasers (Coherent). Laser shuttering and microscope hardware were controlled using NIS-Elements software (Nikon) and a digital-to-analogue converter card (PCI 8733; National Instruments).