Transcription factors and the control of inner ear development

The development of the cells and tissues of the inner ear is controlled in part by the sequential expression of transcription factors, and recent studies have begun to define the roles played by such factors in morphogenesis of the labyrinth. A number of transcription factors have been shown to be expressed during inner ear development. Moreover, several genetic disorders of inner ear development in human and mouse have recently been identified as being caused by mutations of genes controlling transcription factors. In addition, the targeted mutation of several transcription factor genes influence the development of specific inner ear cell types, and suggest a critical role for these factors in controlling inner ear cell lineages. In particular, the POU-domain transcription factors are widely expressed in the developing ear. Gene deletion studies suggest that the Class IV POU-domain transcription factor Brn-3.1 is required for the development of auditory and vestibular hair cells, while Brn-3.0 is necessary for appropriate migration and numbers of spiral ganglion neurons.