Fig. 8. (A) Live imaging of cell membrane of the cystic bulge with FM1-43. Some open mouths of the membrane tunnels (arrowheads) are indicated. However, around the neck of individualizing sperm tail (arrows), no membrane invaginations or up-take of membrane vesicles was observed. (B-E) Double labeling of membrane with FM 1-43 (B) and F-actin cones with GFP-actin (C). Merged image (D) and higher magnification image (E) demonstrate that F-actin occupied the space of the sperm tail neck that is directly adjacent to the cystic bulge membrane. Scale bars: 6 µm in A,E; in B, 12 µm for B-D.