Duplicated genes with split functions: independent roles ofprotocadherin15orthologues in zebrafish hearing and vision

• DOI: 10.1242/dev.01591
• Publication Date: 2005-01-06T01:15:41Z
• Authors: Christoph Seiler; Karin C. Finger-B...; Oliver Rinner; Yuri V. Makhankov; Heinz Schwarz; Stephan C. F. Neu...; Teresa Nicolson
• Keywords: Usher syndrome; Morpholino

In the sensory receptors of both eye and ear, specialized apical structures have evolved to detect environmental stimuli such as light sound. Despite morphological divergence these differing transduction mechanisms, appear rely in part on a shared group genes for function. For example, mutations Usher (USH) cause syndrome visual acoustic-vestibular deficits humans. Several affected been identified, including USH1F gene, which encodes protocadherin 15 (PCDH15). Pcdh15 mutant mice also auditory vestibular defects, although defects are not evident. Here we show that zebrafish two closely related pcdh15 required receptor-cell function morphology or ear. Mutations pcdh15a deafness dysfunction, presumably because hair bundles inner-ear splayed. Vision, however, is mutants. By contrast, reduction pcdh15b activity using antisense morpholino oligonucleotides causes defect. Optokinetic electroretinogram responses reduced morpholino-injected larvae. electron micrographs, morphant photoreceptor outer segments improperly arranged, positioned perpendicular retinal pigment epithelium clumped together. Our results suggest cadherins act within their respective organelles: Pcdh15a necessary integrity stereociliary bundle, whereas Pcdh15b alignment interdigitation with epithelium. We conclude after duplication pcdh15, one gene retained an essential ear other eye.