Overexpression of mud Sis sufficient for converting dividing cells into binucleating ones. (A–F) Cross-sectional views of main cells in early pupal proliferating stage in which mud PBD(A and B), mud L(C and D) or mud S(E and F) are overexpressed. Cells in telophase (A, C and E) or interphase (B, D and F) are shown. Cells are labeled with phalloidin (magenta), anti-α-Tub antibody (green in A, C and E), anti-LamDm0 antibody (green in B, D and F) and anti-P-H3 antibody (blue). Arrowheads in (A, C and E) indicate equatorial planes. The arrowhead in (F) indicates a binucleate cell. Scale bar in (A), 5 μm, is applicable to (A, C and E). Scale bar in (B), 5 μm, is applicable to (B, D and F). (G, G’, I, I’, K and K’) Wing imaginal discs in which FLAG::mud PBD(G) , FLAG::mud L(I) or FLAG::mud S(K) is induced in their dorsal compartment (labeled with GFP). Cells are labeled with phalloidin (magenta), GFP (green) and anti-FLAG antibody (blue). Gray-scale images in (G’, I’ and K’) are of the blue channels in (G, I and K). Scale bar in (G), 100 μm, is applicable to (G, G’, I, I’, K and K’). (H, J and L) Magnified views of (G, I and K) around the dorso-ventral boundaries. Magenta and green channels are shown. Cells with expression of mud S were enlarged in volume (L), possibly as a result of cytokinesis defects. (H’, J’ and L’) Cross-sectional images reconstructed by using a stack of confocal sections at cyan lines in (H, I and L). The epithelium with expression of mud S has an abnormally folded or layered structure (arrowhead in L’). Scale bar in (H), 10 μm, is applicable to (H, H’, J, J’, L and L’).