Fig. 4

AAV-ie-K558R-Atoh1 can regenerate HC-like cells in neonatal mice. a Schematic of AAV-induced hair cell regeneration in WT C57BL/6 neonatal mice. b Immunofluorescence imaging of cochlea transduced with AAV-ie-Atoh1 and AAV-ie-K558R-Atoh1 at dose of 1 × 10¹⁰ GCs. Scale bar: 20 μm. c SEM images of a cochlea injected with AAV-ie-K558R-Atoh1 on P14 in the apical, middle and basal regions. Top row, three rows of OHCs are numbered. Bottom row, boxes show immature (white) and mature (yellow) HC-like cells regenerated by AAV-ie-K558R-Atoh1. Scale bar: 5 μm. d Magnified SEM images of the immature and mature regenerated HC-like cells shown in c as numbered. Stereocilium were observed in these regenerated cells, and kinocilium was artificially colored as red. Immature regenerative cells did not show kinocilia and obvious polarity, whereas those regenerative cells that grew kinocilium (yellow arrowhead) with certain polarity were considered more mature. Scale bar: 1 μm