Fbxo2(CreERT2): A new model for targeting cells in the neonatal and mature inner ear.

The mammalian inner ear contains six sensory patches that allow detection of auditory stimuli as well as movement and balance. Much research has focused on the organ of Corti, the sensory organ of the cochlea that detects sound. Unfortunately, these cells are difficult to access in vivo, especially in the mature animal, but the development of genetically modified mouse models, including Cre/Lox mice, has improved the ability to label, purify or manipulate these cells. Here, we describe a new tamoxifen-inducible CreER mouse line, the Fbxo2(CreERT2) mouse, that can be used to specifically manipulate cells throughout the cochlear duct of the neonatal and mature cochlear epithelium. In vestibular sensory epithelia, Fbxo2(CreERT2)-mediated recombination occurs in many hair cells and more rarely in supporting cells of neonatal and adult mice, with a higher rate of Fbxo2(CreERT2) induction in type 1 versus type 2 hair cells in adults. Fbxo2(CreERT2) mice, therefore, are a new tool for the specific manipulation of epithelial cells of the inner ear and targeted manipulation of vestibular type 1 hair cells.