Mutations of the GJB4 gene; encoding connexin 30.3 (CX30.3); are associated with skin disorders. Recently; this gene was also detected in deaf individuals without skin disorders. However; the functional roles of CX30.3 in the cochlea remain unclear. A primary step toward understanding the role of CX30.3 in hearing and its dysfunction is the documentation of its cellular and sub-cellular locations within the cochlea. In the present study; we located and determined the cellular expression of Cx30.3 within the rat cochlea by using a polyclonal anti-Cx30.3 antibody. Expression of the Cx30.3 protein was detected in the spiral limbus; spiral ligament; spiral ganglion; and stria vascularis by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analyses. Our results indicate the presence and localization of Cx30.3 in the rat cochlea. Knowledge of the spatial distribution of Cx30.3 will provide important insights into its role in the cochleae and normal auditory function.
