Fig. 3.

Peptide-PAINT imaging in Drosophila egg chambers. (A) Basal F-actin in a stage 5 Drosophila egg chamber. (B) Detailed view from A showing that smaller filaments are well-resolved. (C) A single filament from the boxed region in B is shown on the upper right. The graph shows the distribution of localizations perpendicular to the straight filament boxed in yellow after summing along its long axis (see Materials and Methods for details). The filament diameter was measured as 27 nm FWHM by fitting with a Gaussian. (D) Apical F-actin in a stage 5 Drosophila egg chamber. (E) Detailed view from B showing small filaments are visible. (F) The box region in E is shown at the upper right. The graph shows the distribution of localizations perpendicular to the straight filament boxed in yellow after summing along its long axis. The filament diameter was measured as 24 nm FWHM by fitting with a Gaussian. (G) Apical F-actin in a stage 8 Drosophila egg chamber. (H) Detailed view from G showing the clear separation between the cortical F-actin on adjacent cell membranes. (I) The boxed region in H is shown on the upper right. The graph shows the distribution of blinks perpendicular to the regions of the cell cortices boxed in yellow after summing the localizations along each cell cortex. Fitting with two Gaussians gives the distance between the membranes as 111 nm. Data shown are representative of 8 images. Scale bars: 2 µm s (A,D,G); 1 µm (B,E,H).