Fig. 4.

Inner hair cell stereocilia morphology at position 80% (near apex; A, C, E and G) and 30% (near base; B, D, F and H) along the length of the cochlear duct (P4) by scanning electron microscopy showed developmentally immature morphology of hair bundles in the mutants. (G and H) Diminuendo homozygote hair bundles show very little thickening of stereocilia rows. Like the outer hair cells, (C and D) diminuendo heterozygotes and (E and F) Ptprq-CAT-KO homozygotes show a less extreme phenotype but are still distinct from (A and B) the wildtype hair bundles, with an abundance of microvilli. Scale bar, 1.5 μm.