Figure 5. Ultrastructural analysis of cochlear outer hair cell stereocilia in gelsolin/whirler double mutant mice.

a. Outer hair cell morphology from apical turns in double mutant mice. Analysis of outer hair cell morphology from apical turns in double mutant homozygotes for gelsolin and whirlin (Gsn^tm1Djk/Gsn^tm1Djk Whrn^wi/Whrn^wi) compared to whirlin homozygotes (Whrn^wi/Whrn^wi) at 3 months of age. Note that the double mutants show the typical short stereocilia phenotype of the whirler mutant observed particularly towards the outer edges of the stereocilia bundle [17], and do not show the long and straggly stereocilia typical of the gelsolin mutant. (Scale bar, 10 µm). b. Outer hair cell morphology from apical turns in double heterozygous mice. Analysis of outer hair cell morphology from the apex and the middle of the cochlear turn of double heterozygous (Gsn^tm1Djk/+ Whrn^wi/+) and Gsn^tm1Djk/Gsn^tm1Djk Whrn^wi/+ mice at 3 months of age. Double heterozygous mice demonstrate a wild type morphology, whereas Gsn^tm1Djk/Gsn^tm1Djk Whrn^wi/+ mice show the typical long and straggly stereocilia seen in Gsn^tm1Djk/Gsn^tm1Djk mice (Scale bar, 10 µm).