Fig. 2. The a1 isoform of the V-ATPase a subunit does not co-localize with the c subunit in neuron cell bodies. A rabbit antiserum was generated by immunization with a synthetic peptide (13 C-terminal amino acids of the a1 isoform of T. marmorata V-ATPase subunit a) linked to BSA. Specific anti-a1-isoform antibodies were affinity purified on beads coated with the immunopeptide (purified antibody), whereas the serum fraction that did not bound to the beads corresponds to the adsorbed antiserum. (A) Binding of the anti-a1 antiserum (left), adsorbed antiserum (middle) and purified antibodies (right) on T. marmorata cerebellum frozen sections, indirectly visualized with FITC-conjugated anti-rabbit IgG antibodies. Scale bar, 200 µm. (B) Binding of the anti-a1 antiserum (1), adsorbed antiserum (2) and purified antibodies (3) on an immunoblot of synaptosomal proteins (40 µg protein per slot). (C) Distribution of the SV2 synaptic vesicle antigen in a parasagital section of T. marmorata brain (indirect immunolabelling by an anti-SV2 antibody, a peroxidase-conjugated anti-mouse Ig antibody and di-amino-benzidine staining). Scale bar, 5 mm. (D) Double staining of the c subunit (green) and a1 isoform of the a subunit (red) of V-ATPase in T. marmorata electric lobe frozen sections. Binding of mouse anti-subunit-c and rabbit anti-a1-isoform antibodies was indirectly visualized by anti-mouse or anti-rabbit Ig antibodies conjugated to FITC or Alexa 633, respectively. Right-hand panels (merge) correspond to the superimposed stainings. Scale bars, 400 µm (top row) and 200 µm (bottom row). EL, electric lobe; Rh, rhombencephalum.