Gt(ROSA)26Sor^{em1(CAG-Tbx2,-Atoh1,-tdTomato)Zyliu}

CRISPR/cas9 genome editing is used to insert the following from 5' to 3': a CAG promoter, a lox-stop-lox (LSL), a long cistronic DNA element containing Tbx2 fused with three V5 fragments, a P2A sequence, an Atoh1 fused with 3 hemaglutinin tags (HA) flanked by 5' and 3' DHFR (E. Coli dihydrofolate reductase) destabilizing domains, a T2A site and a Tdtomato reporter followed by a WPRE polyA sequence inserted in downstream of exon 1. The DHFR domains flanking Atoh1 create an unstable protein that undergoes rapid degradation in the absence of trimethoprin (TMP). (J:337553)