Figure 2. FAZ restricts basal body migration.

A–C. Top panels, detergent-extracted cytoskeletons of DHC1b^RNAi cells induced for 41 h stained with MAb22 (basal body marker [BB], yellow), L3B2 (FAZ marker, red) and DAPI (blue). Bottom panels: 2-fold magnification of the basal body area of the above images. Diagrams show the position of the old (with a flagellum) and new (without a flagellum) basal bodies as well as positioning of the flagellum (black lines) and the FAZ filament (red lines). DAPI has been omitted from phase contrast images to facilitate visualisation of the flagellar structures. A–B. Presence of a short new FAZ contacting the old one (orange arrows) appears to refrain new basal body migration. C. Extensive basal body migration when the new FAZ is not in contact with the old one (green arrow). D–E. Detergent-extracted cytoskeletons of non-induced (D) or 48h-induced (E) DHC1b^RNAi cells stained with L3B2 (immunogold) showing interaction between new and old FAZ (orange arrows). Basal bodies (BB) are found at the proximal end of the flagella (when present) and are easily recognised by their thicker wall (due to the presence of triplet microtubules [12]).