Fig. S2

Antibody 10C9.1 specifically labels the outer segments of a class of short single cones in the adult zebrafish retina, as seen in Figure 5. A. Localization of 10C9.1 labelling to single cone outer segments as clarified by Bodipy counterstain of lipid-rich photoreceptor cell bodies and outer segments. B–D. 10C9.1 specificity is supported by localized labeling in the adult retina (B), a lack of labeling when adjacent retinal cryosections are treated identically except for omission of primary antibody (C), and by a dramatic decrease in number of cells labeled when 10C9.1 is applied to retinas from adult zebrafish mutants (tbx2b^lor/lor) that have a paucity of UV cones (D). Other negative controls included applying other rat IgGs as primary antibody, and these produced equivalent results to panel C. Retinas in panels B and D were treated identically including equivalent application of 10C9.1 antibody, and simultaneous processing of tissue by inclusion in the same tissue block prior to cryosectioning. The specificity of 10C9.1 is supported by the paucity of labeling in tbx2b^lor/lor retinas (D), which are known to have few UV cones. Scale bars 30 μm. “rods” indicates rod outer segments; dc, double cones; ipl; inner plexiform layer; onl, outer nuclear layer; inl, inner nuclear layer; rgc, retinal ganglion cell layer. E. An alignment of the antigen used to raise 10C9.1 in rats, which represents the 20 N-terminal amino acids from rainbow trout UV opsin plus a C-terminal cysteine to enable linkage of the peptide to the carrier protein keyhole limpet hemocyanin.