Fig. 5. Transgene deletions demonstrate that a functional GAP domain is required for Tum cytokinetic function. Tum transgenes with GAP domain deletions UAS-tum^EIE (A-E) and UAS-tum^YRL (F-L), were expressed in prd stripes in tum^DH15 embryos. In all panels, anti-myc antibody shows the transgene localisation in red, tubulin (or F-actin, panel F) localisation is shown in green and DNA in blue. (A-E) When UAS-tum^EIE is expressed in tum^DH15 embryos, it fails to localise correctly or rescue cytokinesis. Binucleate cells (asterisks, A) are readily detected in stripes of UAS-tum^EIE-expressing cells, whereas midbody remnants are rarely found. Cells in the mitotic cycle in these stripes have diffuse Tum^EIE protein at metaphase (arrow, C), anaphase (arrowhead, C) and telophase (arrow, E). (F-J) When UAS-tum^YRL is expressed in tum^DH15 embryos, it localises to the cortex equator, but also fails to rescue cytokinesis. Binucleate cells (asterisks, F) are readily detected in stripes of UAS-tum^YRL-expressing cells, whereas midbody remnants are rarely found. Tum^YRL localises to the ends of microtubules at the cell equator at anaphase (arrowhead, F) and this localisation does not change throughout telophase or the subsequent interphase (arrowheads, G,H,I,J). Bar, 5 µm. Grayscale images for all color channels can be viewed in supplementary material Fig. S4.