Observed number of nuclei in M. abdita.

Number counts based on DAPI-stained embryos (Figure 4 and File S2) are compared to those expected considering preceding mitotic divisions. Note that expected numbers are overestimates from C9 onward, as nuclei migrate out of the plane of focus and some remain behind in the yolk (also outside the focal plane). C14 embryos have nuclei, which are too densely packed to be reliably counted. Density refers to the number of full nuclei falling into a 45×45 mm square placed in the middle of a scaled embryo (see text for details).