MTs, Rac-GTP, and Arp3 distributions in telophase 11 compartments following Ciliobrevin D and control injections. (A) Single sections of co-imaged PIP₂ probe and Jupiter-GFP at telophase 11 following injection of Ciliobrevin D or DMSO carrier control. Yellow corner brackets show astral centrosomal MTs at nascent caps. The white bracket shows the central mitotic spindle. Seen in six embryos each. (B) Single sections of co-imaged PIP₂ and Rac-GTP probes at telophase 11 following injection of Ciliobrevin D or DMSO carrier control. Corner brackets indicate nascent caps and arrows indicate surrounding pseudocleavage furrows. Graph plots nascent cap-to-furrow signal ratios versus nascent cap tubule numbers in embryos injected with Ciliobrevin D or DMSO carrier control. P value indicates significant differences both between the signal ratios and between the tubule numbers for the Ciliobrevin D and control injections. (C) 1.5-µm projections of coimaged probes for PIP₂ and Arp3 at telophase 11. Corner brackets indicate nascent caps and curly bracket indicates the center domain between caps. Graph plots nascent cap-to-compartment center signal ratios versus nascent cap tubule numbers in embryos injected with Ciliobrevin D or DMSO carrier control. P value indicates significant differences both between the signal ratios and between the tubule numbers for the Ciliobrevin D and control injections.