Variable number and distribution of UV cones in adult <i>tbx2b</i> mutants.

<p>A, B) Flat-mounted retinas from <i>sws1:EGFP</i> wild-type fish; the optic disc is indicated by an asterisk; dorsal is up. C–H) Six examples of <i>tbx2b; sws1:EGFP</i> mutant retinas. Residual UV cones are typically at or near the dorsal margin (curved white arrows) and immediately dorsal to the optic disc (arrowhead). Scale bar: 500 µm (A–H).