Supporting information for Haydar et al. (2003) Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0437969100
Movie 3.
This movie from an E14 slice shows the divergent behavior of daughter cells after division in the VZ. The mother and daughter cells were pseudo-colored green (for the asymmetric division) and red (for the symmetric division). The first cell (green) approximates the VZ and undergoes significant rotation of the metaphase plate before dividing at a 47° plane of cleavage. The resulting daughter cells rapidly separate, with the basal cell migrating away and out of the plane of focus leaving the apical daughter behind at the ventricular surface. In contrast, the subsequently dividing red cell undergoes very little spindle rotation and divides quickly at a 27° plane of cleavage. The red daughters then remain closely opposed at the VZ surface for the remainder of the imaging. Thus, based on resulting behavior of daughter cells, cleavage planes above 45° result in asymmetric behavior whereas shallower cleavages yield symmetrical daughters. It is interesting to note that the two cleavages occur side-by-side, suggesting that signals in the macroenvironment are likely not the cause of the different division behavior.