Supplementary Figure 4: Immuno-gold labeling of actin and MyoII.

Electron micrographs of immuno-gold labelled 70 nm sections of high-pressure frozen and freeze-substituted embryos. (A) Anti-actin labeling of actin bundles in LE cell protrusions. The bundle in the lamellipodium is cut obliquely, while in the overlaying filopodium (red arrows) it is cut across. Arrows point out gold particles. The insert shows a magnification of the lamellipodial actin bundle boxed in white. (B) Anti-actin (C) and anti-MyoII labeling of the actin/MyoII purse string and the respective magnification of the boxed areas in the insert. The characteristic texture of the actin/Myo2 cable cannot be seen in the projection images. However, it can be distinguished due to its higher electron density.