Changes to cortical localizations of Rac-GTP and SCAR from metaphase to telophase of cycle 11. (A) Single sections of coexpressed probes for Rac-GTP and PIP₂ at metaphase 11, anaphase 11, and telophase 11. Arrows indicate pseudocleavage furrow surrounding the compartment. Corner brackets indicate a nascent cap at telophase. The overall signal decreases from metaphase to telophase due to photobleaching. Enrichment of Rac-GTP at apical PM folds of the nascent cap can be seen by comparing levels at apical folds to levels at pseudocleavage furrows at each stage. Seen in 7/7 embryos. (B) Signal ratios of probes for Rac-GTP and PIP₂ at apical PM folds versus surrounding pseudocleavage furrows at metaphase 11, anaphase 11, and telophase 11. Both probes were measured at the same sites. (C) Single sections of co-expressed probes for SCAR and PIP₂ at metaphase 11, anaphase 11, and telophase 11. Arrows indicate pseudocleavage furrow surrounding the compartment. Corner brackets indicate nascent cap at telophase. The overall signal decreases from metaphase to telophase due to photobleaching. Enrichment of SCAR at apical PM folds of the nascent cap can be seen by comparing levels at apical folds to levels at pseudocleavage furrows at each stage. Seen in 6/6 embryos.