Metaphase spindle formation and metaphase-anaphase transition are normal during binucleation. (A and C) Localization of polo to kinetochores in main cells in metaphase during cell division in early pupa (A) and during binucleation in mid-pupa (C). Cells are labeled as indicated at the bottom of (A). En face views (A) and cross-sectional views (C). Scale bar, 5 μm, is applicable to (A and C). (B, B’, D and D’) Levels of cyclin B. En face images of the wing disc epithelium in third-instar larva as an example of proliferating tissue (B and B’) and the accessory gland epithelium in mid-pupa as an example of binucleating tissue (D and D’). Cells in (B and D) are labeled as indicated at the bottom right of (B). Intensities of cyclin B::GFP in (B) and (D) are represented by a rainbow-color scale, with red meaning high intensity and blue meaning low intensity. Magenta dashed lines indicate outlines of mitotic cells in various M-phase subphases. Scale bar in (B), 10 μm, is applicable to (B, B’, D and D’).