Figure 3 .

Prophase/prometaphase arrest of endos^215-4 mutant neuroblasts. Brains were dissected from late larvae of either w¹¹¹⁸; P{H2AvD-RFP}/+ (controls expressing red fluorescent protein-labeled histone H2AvD) or w¹¹¹⁸; P{H2AvD-RFP}/+; endos^215-4/endos^215-4. Living neuroblasts chosen for filming had already begun chromosome condensation and were thus in prophase. Frames are shown at 2-min intervals. Wild-type cells (n = 8) all progressed through anaphase by 30 min. None of the endos mutant neuroblasts formed a clearcut metaphase plate or displayed anaphase chromosome separation after 60 min or more (n = 10).