The immunohistochemical analysis of pendrin in the mouse inner ear.

Pendred's syndrome (PS) is an autosomal recessive disorder characterized by deafness and goiter, which are caused by mutations in the Pendred's syndrome gene (PDS). PDS encodes a membrane protein named pendrin that is considered to act as an anion transporter. An expression pattern of the PDS ortholog (Pds) mRNA in the auditory and vestibular systems has been reported in mice, and the localization of pendrin has been reported recently. We generated antipeptide antibodies against human pendrin, and performed immunohistochemical analysis of mouse inner ears. We detected pendrin in the endolymphatic duct and sac, and the utricle, saccule, and external sulcus. In the endolymphatic duct and sac, the expression of pendrin was apparent at the apical membrane. In addition, we detected pendrin in the spiral ligament, Claudius cells, Deiter's cells, and the spiral ganglion of the cochlea. Our results are key to defining the role of pendrin in inner ear development and elucidating the pathogenic mechanisms underlying deafness in PS.