Fig. 5

VAMP-2-EGFP labeling and actin remodeling during furrow deepening and apposition. (A to C) Embryos were fixed during (A) early and (B) late deepening, as well as during (C) apposition of the 1st cell division to monitor the redistribution of VAMP-2-EGFP labeling (green; panels i and v), F-actin remodeling (red; panels ii and vi), and any potential co-localization between the two (panels iii and vii). Panels Ai to Aiii and Bi to Biii are stacks of confocal sections that have been projected as a single image, while panels Ci to Ciii are single optical sections taken from image stacks as these showed the labeling more clearly. Panels Av to Avii, Bv to Bvii and Cv to Cvii represent side projections in the x–z plane of the corresponding x–y plane stack projections. Red, white and yellow arrowheads indicate VAMP-2-EGFP labeling of the furrow membrane, the PAEs and the overlap between the two, respectively, while the white arrows indicate the contractile band. Panels Aiv, Biv and Civ illustrate schematics of embryos to show where the optical stacks (used to construct the images shown in panels A and B) or single sections (used for the top projection images shown in panels Ci to Ciii) were obtained from within the dividing embryo. (D) Time-series of single confocal sections showing the dynamics of actin remodeling in a representative embryo undergoing 1st cleavage, imaged from a facial view. Images are of live embryos injected with low concentrations of rhodamine–phalloidin. The contractile band and PAEs are indicated by white arrows and arrowheads, respectively, while the finger-like projections that extend from the PAEs are indicated by blue arrowheads.