Nuclear asymmetry precedes lobe formation in binucleate PGCs. (a and a’) Time-lapse images of DIC and Mem^PGC in a zen-4 embryo (subjected to temperature-shift regimen IV) with a binucleate PGC. Nuclei (asterisks in first and last panel) are present on one side of the PGC before it extends in length and begins to form a lobe (L in last panel). (b–b’’’) NMY-2-YFP^PGC (arrowheads in b’’) at the lobe neck in a binucleate zen-4 PGC. Nuclei (asterisks) and the lobe (L) are indicated in the first panel, which shows Mem^PGC (b), and the cell membrane (white dashed line) and nuclei (blue dashed lines) are indicated in the DIC image (b’). Scale bar, 5 µm.