Mouse Strain Fate Mapping and Hair Cell Ablation

The following mouse strains were used: Atoh1-CreERTM, a gift from S. Baker, St. Jude’s Hospital, Memphis, TN (31 (link)), Rosa26-tdTomato (The Jackson Laboratory, stock 007908) (32 (link)), Pou4f3-DTR (The Jackson Laboratory, stock 028673) (7 (link)), and Plp1-CreERT (The Jackson Laboratory, stock 5975) (63 (link)). Mice of both sexes were used. To induce Cre-recombinase activity for fate mapping, Atoh1^CreERTM/+; Rosa26^tdTomato/+ mice were injected with tamoxifen (intraperitoneally, 0.075 mg/g dissolved in corn oil; Sigma) at P1. To selectively ablate hair cells, mice carrying the Pou4f3-DTR allele were treated with DT at P1 (intramuscularly, 4 ng/g) immediately prior to tamoxifen injection. For Pou4f3^DTR/+; Plp1^CreERT/+; Rosa26R^tdTomato/+, DT was administered at P1 (intramuscularly, 4 ng/g) to ablate hair cells followed by tamoxifen injection at P8 (intraperitoneally, 0.075 mg/g dissolved in corn oil) for Cre activation (11 (link)). Mice were housed in the Stanford University Veterinary Service Center that is fully accredited by the Association for Accreditation and Assessment of Laboratory Animal Care. Food and water were available ad libitum. The mouse room was maintained on a 12-h light/12-h dark cycle in a quiet room. All protocols were approved by the Animal Care and Use Committee of the Stanford University School of Medicine (18606).