Sensory hair cells deep within the inner ear convert the mechanical force of sound waves into signals that travel along the auditory neurons to give rise to the sensation of hearing in the brain.
A microscopic formation called the mechano-electric transducer (MET) is located at the top of the sensory hair cells and is responsible for initiating the process that converts the energy of sound waves into neurological signals. A molecule called cadherin 23 (CDH23) is believed to be a major component of the MET.
Zheng and colleagues wanted to investigate the nature of CDH23 and discover if any other significant proteins are associated with it and what their function might be. They had already identified one protein related to the MET, called carcinoembryonic antigen-related cell-cell adhesion molecule (CEACAM), and are further investigating its interaction with CDH23 and how and where its gene is expressed in the inner ear.
Zheng discovered that the gene for CEACAM is expressed in outer hair cells but not inner hair cells.
Zheng and colleagues are now investigating when the gene for CEACAM is expressed in the inner ear during development.