Extended Data Fig. 5: Scanning electron microscopy of cello mice and auditory function of Ikzf2cello/del890 compound heterozygotes.
From: Helios is a key transcriptional regulator of outer hair cell maturation
a, Scanning electron micrographs of the organ of Corti of cello mice from P16 to 18 months of age. Representative images from the mid-region of the cochlear spiral are shown. Scale bars, 10 µm. n = 3 (P16 Ikzf2cello/+, P16 Ikzf2cello/cello, 1-m Ikzf2cello/cello, 9-m Ikzf2+/+, 18-m Ikzf2+/+, 18-m Ikzf2cello/+, 18-m Ikzf2cello/cello), n = 4 (P16 Ikzf2+/+, 1-m Ikzf2+/+, 3-m Ikzf2+/+, 3-m Ikzf2cello/cello, 6-m Ikzf2+/+, 6-m Ikzf2cello/cello, 9-m Ikzf2cello/+, 9-m Ikzf2cello/cello) and n = 5 (1-m Ikzf2cello/+, 3-m Ikzf2cello/+, 6-m Ikzf2cello/+) biologically independent samples. b–d, Scanning electron micrographs of OHC stereocilia bundles of cello mice at P16, showing that wild-type Ikzf2+/+ (b), Ikzf2cello+ (c) and mutant Ikzf2cello/cello (d) mice display overall expected bundle patterning. Images are from the mid-region of the cochlear spiral. Scale bars, 1 µm. n = 3 biologically independent samples for each genotype. e, The genomic and domain structure of Ikzf2del890. Black, 5′ untranslated region; light grey, N-terminal DNA-binding domain; dark grey, C-terminal dimerization domain. The Ikzf2cello mutation lies in ZnF6. The del890 mutation deletes exon 4 and the surrounding intronic sequence. f, Averaged ABR thresholds for Ikzf2cello/del890 compound heterozygotes at 1 month of age, showing increased thresholds (≥40 dB SPL) at all frequencies tested compared to Ikzf2+/+, Ikzf2cello/+ and Ikzf2del890/+ control colony mates. Data are mean ± s.e.m. n = 4 (Ikzf2+/+, Ikzf2+/del890), n = 2 (Ikzf2cello/+) and n = 5 (Ikzf2cello/del890) biologically independent samples. Ikzf2cello/del890 vs Ikzf2+/+: *P = 0.011 (8 kHz), **P = 0.002 (16 kHz), ****P < 0.0001 (32 kHz), ***P = 0.0001 (click); Ikzf2cello/del890 vs Ikzf2cello/+: P = 0.078 (8 kHz), *P = 0.034 (16 kHz), **P = 0.001 (32 kHz), **P = 0.001 (click); Ikzf2cello/del890 vs Ikzf2+/del890: *P = 0.025 (8 kHz), **P = 0.009 (16 kHz), ***P = 0.0002 (32 kHz), ***P = 0.0002 (click) (one-way ANOVA with Tukey post hoc test).
