Morphological analysis of photoreceptors indicates that metronidazole does not damage neighbouring cells.

<p>UV cones expressing nitroreductase (NTR) were ablated after the addition of prodrug metronidazole (MTZ) (A–D), while <i>nfsB</i>-mCherry persisted in transgenic fish treated with DMSO vehicle control (E–H). 24 hours after ablation, UV cones lacking NTR-expression appeared morphologically normal (C) based on their GFP expression compared to controls (G). Red-green double cone pairs were detected with the antibody zpr1. Zpr1 labelling was consistent following MTZ ablation (B) showing normal cell morphology compared to the controls (F). Scale bar = 25 µm. A magnified view of remaining UV cones (I) with normal morphology comparable to controls is presented from a separate sample (J, Scale bar = 5 µm).