In the mammalian inner ear, endolymph is produced and resorbed by a complex series of epithelia. We show here that estrogen-related receptor β (ERR-β; NR3B2), an orphan nuclear receptor, is specifically expressed in and controls the development of the endolymph-producing cells of the inner ear: the strial marginal cells in the cochlea and the vestibular dark cells in the ampulla and utricle. Nr3b2-/- strial marginal cells fail to express multiple ion channel and transporter genes, and they show a partial transformation toward the fate of the immediately adjacent Pendrin-expressing epithelial cells. In genetically mosaic mice, Nr3b2-/- strial marginal cells produce secondary alterations in gene expression in the underlying intermediate cells and a local loss of strial capillaries. A systematic comparison of transcripts in the WT versus Nr3b2-/- stria vascularis has identified a set of genes that is likely to play a role in the development and/or function of endolymph-producing epithelia.
ASJC Scopus subject areas
- Molecular Biology
- Biochemistry, Genetics and Molecular Biology(all)
- Developmental Biology
- Cell Biology