Inner-ear malformation and sensory defects in Eya1 hypomorphic mutant mice. (A–G) Paintfilled inner ears at E18.5 from wild-type, Eya1+/− heterozygotes, Eya1bor/bor homozygotes and Eya1bor/− compound heterozygotes. Asterisks indicate truncated semicircular canals and missing ampullae in mutants. Arrow in (B) points to truncated endolymphatic duct (ed). Arrow in (D) points to the shortened cochlea (co). (H–M) E18.5 inner-ear sections stained with an anti-MYO7A antibody showing sensory epithelium of the semicircular canal, utricle and saccule in Eya1bor/+ heterozygotes and malformation of these structures in Eya1bor/bor and Eya1bor/− mutants. aa, anterior ampulla; ac, anterior crista; asc, anterior semicircular canal; la, lateral ampulla; lc, lateral crista; lsc, lateral semicircular canal; pa, posterior ampulla; psc, posterior semicircular canal; s, saccule; u, utricle. Scale bars: 50 µm.