Segregation of long chromatids is associated with a slight increase in spindle length and a shift of the spindle toward the GMC. (a) Still images from time-lapse movies of control and I-CreI neuroblasts expressing H2Av::RFP and GFP::Jupiter during cytokinesis. Top panels are inverted images of GFP::Jupiter signal. Bottom panels are DIC images merged with H2Av::RFP signal (red). Asterisks designate the position of the centrosomes. The arrows point to the prominent asters in elongated cells. Broken lines outline the cells. Bar, 8 µm. (b) Scheme of an elongated cell showing how the spindle length is measured (see Materials and methods). (c) Scatter dot plot with mean ± SD showing the normalized spindle length for control and elongated I-CreI cells. (d) Scheme of control and I-CreI cells indicating how the GMC, neuroblast spindle length, and centrosome–to–polar cortex distances were measured for the graphs in e and f. (e) Scatter dot plot with mean ± SD showing the ratio of the GMC spindle length to the neuroblast spindle length. This ratio reflects the displacement of the spindle toward the GMC in I-CreI cells. (f) Scatter dot plot with mean ± SD showing the detachment of the centrosome from the polar cortex in both neuroblast and GMC I-CreI cells compared with control cells. n = number of cells.