This time lapse series illustrates the early division up to the four-cell stage of a C. elegans embryo expressing YFP::CDC-48 by DIC and fluorescence microscopy. YFP::CDC-48, like YFP::UFD-1 and YFP::NPL-4, are cytosolic during mitosis, but accumulate in the nucleus after its reformation. The first C. elegans embryonic division of the P0 zygote is asymmetric and generates an anterior AB cell, and a smaller posterior P1 cell. These cells have different developmental fates and division timing, with AB dividing approximately 2 min before P1. Additionally, in early C. elegans embryonic cell cycles, S and M phases rapidly alternate without apparent gap phases. The movie corresponds to experiments shown in Fig. 1A and Fig. S1 and Movie 1 of Mouysset et al. Movie is CIL 25628 and original data file is CIL 35123.
The YFP translational fusion gene, YFP::cdc-48, was cloned into the pAZ-YFP(N-terminal) bombardement vector, which contains the pie-1 promoter for maternal expression and the unc-119(+) marker for selection of transgenic worms. The constructs were bombarded into unc-119(ed4) mutants. Eggs were extruded in M9 buffer from dissected adult worms and mounted on 2% agarose pads. Recordings were acquired in 20- or 10-second intervals (2 × 2 binning) with an Orca ER 12-bit digital camera (Hamamatsu) mounted on a wide-field microscope (Axioplan2, 40×/1.3 Plan-Apochromat objective; Carl Zeiss) or a spinning disk confocal microscope (Axioplan, 63×/1.4 Plan-Apochromat objective; Carl Zeiss; and Yokogawa disk head). Image processing was done with AxioVision (Carl Zeiss) or MetaMorph software (Universal Imaging).
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