Figure 3.

Knock-out of β-catenin in sensory progenitors inhibits hair cell development. A, The number of hair cells was decreased in the sensory region after deletion of β-catenin was induced at E12.5 in sensory progenitors (Sox2-positive) of Sox2-CreER;β-catenin^{flox(exon2–6)} mice. Low-magnification views are shown at E15.5. B, Two to three rows of Atoh1-positive outer hair cells were observed lateral to the myosin VIIa-positive inner hair cells in the midbasal region; some outer hair cells expressed myosin VIIa in a littermate lacking Cre. A single shortened row of hair cells had developed in β-catenin^{ΔΔexon2–6} mutants. No change in Sox2 expression was seen. C, The difference in hair cell number was significant (p < 0.01).