Inner ear of a mouse
One of the most common genetic defects in human deafness is the disappearance of an important family of proteins: the claudins. Claudins are the most critical component of tight junctions (shown here in blue), the place where two adjacent cells meet. Imagine a tight circle of people linking arms to protect what’s inside; tight junctions are what protect a tissue from unwanted molecules or cells trying to pass through. When mice cannot make claudin, the tight junctions in the cochlea (the spiral-shaped portion of the inner ear) are disrupted, robbing them of their hearing sensitivity.
Image by Dr. Alexander Gow and Cherie Southwood, Wayne State University.