Fig. 2. Anti-acetylated tubulin immunoreactivity is distributed within varicosities of intact Rohon-Beard peripheral processes. (A) In a 60 hpf wild-type embryo, zn-12 immunoreactivity reveals the peripheral processes of RB cells are intact and form a mesh of fine fibers. (B) By contrast, aat immunoreactivity appears as discrete varicosities within a subset of the peripheral processes, referred to here as the major peripheral processes. (C) In double-antibody experiments, the peripheral processes of a 60 hpf embryo were co-labeled for aat (FITC, yellow) and zn-12 (Rhodamine, red) immunoreactivities. The former recognizes a mature form of tubulin, whereas the latter binds to an extracellular sugar epitope on the plasma membrane. Even though the peripheral processes appear intact at the level of the plasma membrane (red, arrows), aat immunoreactivity is found in only discrete subregions (yellow) of the peripheral processes, indicating that redistribution of aat immunoreactivity occurs before process fragmentation. Scale bars: 10 µm.
