Specific expression of Kcna10, Pxn and Odf2 in the organ of Corti.
Bottom Line: The development of the organ of Corti and the highly specialized cells required for hearing involves a multitude of genes, many of which remain unknown.Kcna10, a tetrameric Shaker-like potassium channel, is expressed strongly in the hair cells themselves.The roles of these genes are yet to be elucidated, but their specific expression patterns imply potential functional significance in the inner ear.
Affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK.Show MeSH
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Mentions: Expression of Odf2 showed a marked difference between sensory regions in the organ of Corti and in the vestibular system. In the organ of Corti, neural tissue showed clear Odf2 expression right from E14.5 (Fig. 2a). From E14.5 to E18.5, Odf2 expression marked the neural dendrites as they extended to innervate first the inner and then the outer hair cells, as can be followed in Fig. 2a–c. At E18.5 and subsequent ages, the strongest Odf2 expression was in the portions of dendrites directly underneath hair cells, presumably at synapses. Hair cells were faintly stained from E16.5 (Fig. 2b), and the cells of Claudius from E18.5 (Fig. 2c). At P0, root cells showed faint expression as well (data not shown). The root cells and the root cell processes showed strong expression at P3 (data not shown) and P5 (Fig. 2d). At P5, strong expression could also be seen in the apical region of Kölliker’s organ, and moderate expression in the interdental cells (Fig. 2d). The strongest expression was still in the dendrites, though (Fig. 2e). However, at all ages hair cells in the organ of Corti showed only very weak expression of Odf2 (Fig. 2). In contrast, vestibular hair cells in the cristae showed stronger Odf2 expression. This began at E16.5, but was strongest at P5 (Fig. 2g). Hair cells in the maculae did not show anywhere near the same strength of expression, as Fig. 2f demonstrates. As in the cochlea, neurons in the vestibular system showed strong expression of Odf2 (Fig. 2f and g). Like Pxn, Odf2 expression was cytoplasmic. In adult mice, Odf2 expression was marked in the interdental cells, Boettcher cells, the root cells and root cell processes. Fainter expression was also visible in the hair cells of the maculae and cristae (Fig. 2h–j).
Affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK.