Fusion of nuclei during mitosis of nuclear cycles in maternal haploid (mh) embryos leads changes in ploidy. Embryonic nuclei labeled with histone-GFP were imaged by confocal microscopy from NC12 until gastrulation at 55 second intervals. During anaphase of NC14, the haploid daughter nuclei of 3 haploid nuclei (white circles mark the centroids, while blue circles indicate position of previous time point) collide to give rise to 1 haploid, diploid and triploid progenitor. Tracking confirmed that the 3 nuclei resumed mitotic division at gastrulation. Another group of 3 haploid nuclei (arrow further right) merged during metaphase of NC to give rise to two triploid daughter nuclei. Time is indicated in min:sec.