Figure 7: Fate tracing of multipotent progenitors in the cochlea during development.

(a) Co-immunostaining for Neurod1 (green) and Myo7a (blue) of Eya1^CreER;Rainbow cochlea (2 mg tamoxifen given at E13.5). Arrows point to partial overlap of Neurod1 labelling with RFP in Eya1-lineage marked spiral ganglion cells, which is most likely due to different cells either closely intertwined or at different focal planes. (b) Co-immunostaining with anti-β-Gal (green) and -Neurod1 (red) on section of wild-type spiral ganglion region (SPG) at E13.5. (c) LacZ staining of Eya1^LacZ cochlea at E14.5 showing Neurod1⁻ high LacZ (Eya1)⁺ cells in the SPG (arrows). (d) Co-immunostaining for Neurod1 (red) and β-Gal (green) on section from Eya1^CreER;R26R^LacZ cochleae at P0 (3 mg tamoxifen at E12.5). Arrows point to a few Neurod1⁺ Eya1-lineage marked cells in the SPG. (e) Co-immunostaining for NF (red) and β-Gal (green) on section from Eya1^CreER;R26R^LacZ cochleae at P0 (3 mg tamoxifen at E12.5). Open arrowhead points to Eya1-lineage marked cells on the nerve fibres projecting to the OC. (f) Co-immunostaining for Neurod1 (green) and Myo7a (blue) of Rosa^CreER;Rainbow cochlea (∼2 mg tamoxifen given at E12.5). Scale bars: 50 μm.