This transgene contains the coding sequence for enhanced green fluorescent protein (EGFP), followed by a polyadenylation signal, inserted into the mouse genomic bacterial artificial chromosome (BAC) RP23-34I18 at the ATG transcription initiation codon of the Iroquois related homeobox 3 (Drosophila) (Irx3) gene so that expression of the reporter mRNA/protein is driven by the regulatory sequences of the mouse gene. (J:100296, J:100256)