Fig 6. Flagellum-to-flagellum connections were mediated by a small membrane bound bridge structure.

A, B) Conventional scanning electron micrographs of parental (A) and FAZ2 null mutant (B) cells through the cell cycle. The connection is formed between the flagella (white arrow) as soon as the new flagellum exits the cell body. Scale bar is 5 μm. C) High-resolution scanning electron micrographs showing the bridge that mediates flagellum-to-flagellum connection (the white box indicates the position of the area enlarged beneath). Scale bar, 5 μm (A, B, C image on the left) and 500 nm (C, lower panel). D) Slices through the tomogram showing the connections (white arrow) between the flagellum and the connecting bridge structure. The asterisks indicate the electron density within the connecting structure. Scale bar, 200 nm. E) Model of the connection generated from tomogram of connected flagella in the FAZ2 null mutant.