Tprn mRNA expression in WT and Tprn ^−/− mouse organ of Corti (OC) and stria vascularis (SV) using RNAscope probes. (A) Regions of Tprn cDNA sequence of two RNAscope probes used to detect mouse Tprn mRNA. Probe-Mm-Tprn-01 targets the sequence toward the N-terminus of Tprn mRNA. Probe-Mm-Tprn-02 targets sequence for the C-terminus of Tprn mRNA. (B) Expression of Tprn mRNA in hair cells of the OC and SV at P3 Tprn mutant mice (Tprn^−/−) and P3 WT littermates (Tprn^+/+) using Probe-Mm-Tprn-01 (red) and Probe-Mm-Tprn-02 (red). Hair cells were highlighted by Myo7a (Probe-Mm-Myo7a-C2, magenta). Three OHCs and one IHC are visible in sections and highlighted by Myo7a signal (magenta). Tprn mRNA signal (red) overlaps with Myo7a signal (magenta) in Tprn^+/+ but absent in Tprn^−/− OC. SV was highlighted by Cldn11 mRNA encoding tight junction claudin 11 (Probe-Mm-Cldn11-C3, green), a marker of SV basal cells. Tprn mRNA signal (red) overlaps with Cldn11 mRNA signal (green) and is also present in other SV cells in Tprn^+/+ but not in Tprn^−/− SV. Scale bars are 50 µm.