Fig. 3.

PAR-2 and PAR-3 regulate myosin dynamics in ect-2(ax751) zygotes. (A) Time-lapse confocal images of cortical sections of ect-2(ax751) C. elegans zygotes expressing NMY-2::GFP and treated with the indicated RNAi. The same zygotes are shown at two stages: during pronuclear migration and at NEBD. During this time, NMY-2::GFP levels increase in the anterior cortex in the control and throughout the whole cortex in par-2(RNAi) zygotes and this increase is dependent on PAR-3 (see Movies 2 and 6-8 in the supplementary material). (B) Quantification of cortical NMY-2::GFP. The fold increase in cortical NMY-2::GFP was calculated by comparing fluorescence intensities in the cortex of live zygotes imaged during pronuclear migration and again during NEBD (see Materials and methods). (C) Immunostaining of phospho-MLC-4 (green) in wild-type and ect-2(ax751) zygotes that express no transgenes. DNA staining is with DAPI (blue). (D) Timing of the NMY-2::GFP wave in pri-1(RNAi) and control zygotes. Each line represents one embryo filmed from pronuclear meeting to NEBD. Red dots denote the timing of the NMY-2::GFP wave, and black dots denote the timing of NEBD relative to pronuclear formation.