Zebrafish ush1c is expressed in retina and the inner ear. (A) The predominant splice form of ush1c corresponds to mammalian isoform A, with 21 exons that produce a 1.6 kb mRNA. A hydrophobicity plot of zebrafish (red) and human (blue) isoform A protein sequence shows conserved residue polarity. % amino acid identity with human protein is indicated below the plot. The positions of the ush1cfh293 nonsense mutation (red arrowhead), the MO target (green arrowhead) and the region recognized by the zebrafish harmonin antibody (red bar) are indicated. (B) At 5 dpf, ush1c transcripts are abundant in the inner retina (black arrow), the sensory patches of the ear (white arrows), the intestinal tract (i) and the swim bladder (sb). Fainter expression in the brain (b) and trunk muscles (m) is also observed. (C) High-magnification view of a 5 dpf whole-mount zebrafish ear showing ush1c expression in all sensory patches (ac, lc, pc: anterior, lateral and posterior cristae, respectively; am: anterior macula) and an adjacent head neuromast (n). (D) ush1c transcripts are restricted to cells in the inner nuclear layer in 5 dpf sectioned retina. (E) Central section of an adult zebrafish retina showing continued strong expression in the inner retina; expression is detected in the outer nuclear layer as well. onl, outer nuclear layer; inl, inner nuclear layer; gcl, ganglion cell layer. Scale bars: 100 μm (B); 20 μm (C); 50 μm (D,E).