Figure 6

Three types of mud splicing isoforms differently regulate morphologies of binucleating cells. (A–J) Rescue of mud mutant phenotypes by each mud isoform. Cross-sectional views of main cells in metaphase (A, D and G), late anaphase (B, E and H) and telophase (C, F, I and J) during the binucleation stage in mutants hemizygous for mud ⁴ with overexpression of FLAG::mud ^PBD(A–C), FLAG::mud ^L(D–F) or FLAG::mud ^S(G–J). Cells are labeled with phalloidin (magenta), anti-α-Tub antibody (green) and anti-P-H3 antibody (blue). The cell in (I) shows neither a central spindle assembly nor furrow progression. The cell in (J) shows furrow progression but no central spindle assembly. Arrowheads in (C, F, I and J) indicate equatorial planes. Scale bar in (A), 5 μm, is applicable to (A–J). (A’–J’) Schematic diagrams of (A–J). Cross-sectional views of mud ^S- knockdown main cells in metaphase (K), late anaphase (L) and telophase (M) during the binucleation stage. Cells are labeled with phalloidin (magenta), anti-α-Tub antibody (green) and anti-P-H3 antibody (blue). Arrowhead in (M) indicates an equatorial plane. Scale bar in (A), 5 μm, is applicable to (K–M). (K’–M’) Schematic diagrams of (K–M). Effects on cell morphologies in each of the three rescued genotypes ((A–C): mud ⁴ hemizygotes rescued by mud ^PBD, (D–F): mud ⁴ hemizygotes rescued by mud ^L, (G–J): mud ⁴ hemizygote rescued by mud ^S) and in mud ^S-knockdown cells (K–M) are listed under each set of diagrams.