Absence of Embigin accelerates hearing loss and causes sub-viability, brain and heart defects in C57BL/6N mice due to interaction with Cdh23(ahl)

Mouse studies continue to help elaborate upon the genetic landscape of mammalian disease and the underlying molecular mechanisms. Here, we have investigated an Embigin(tm1b) allele maintained on a standard C57BL/6N background and on a co-isogenic C57BL/6N background in which the Cdh23(ahl) allele has been “repaired.” The hypomorphic Cdh23(ahl) allele is present in several commonly used inbred mouse strains, predisposing them to progressive hearing loss, starting in high-frequency regions. Absence of the neural cell adhesion molecule Embigin on the standard C57BL/6N background leads to accelerated hearing loss and causes sub-viability, brain and cardiac defects. Contrastingly, Embigin(tm1b/tm1b) mice maintained on the co-isogenic “repaired” C57BL/6N background exhibit normal hearing and viability. Thus Embigin genetically interacts with Cdh23. Importantly, our study is the first to demonstrate an effect of the common Cdh23(ahl) allele outside of the auditory system, which has important ramifications for genetic studies involving inbred strains carrying this allele.