CELL FATE SPECIFICATION IN THE INNER-EAR

From its origin as a single ectodermal patch, the inner ear becomes a labyrinth of chambers housing six to eight sensory organs. Along the w ay, specific cell fates are realized. The secrets underlying these cel l fate specifications are beginning to be revealed through the applica tion of several molecular-genetic approaches. Recent papers describing such approaches have included gene expression studies in the early ot ic epithelium and inner ear sensory epithelia, large-scale screens of zebrafish mutants to identify ear defects, and targeted gene perturbat ions of neurotrophins, of their receptors or of the Brn-3. I transcrip tion factor in mice.