The FLAG-T2A-tdTomato-SV40 poly(A)-LoxP-Neo-Lox cassette was inserted in frame after the last codon of Pou4f2 by homologous recombination in the ES cells. It is a null allele designed to express both zsGreen and CreERT2 from the Atoh7 promoter. It is designed as a functional wild-type allele expressing a FLAG-tagged version of Pou4f2 and tdTomato from the Pou4f2 promoter (J:297659)