The single-copy transgene comprises a chicken beta actin promoter followed by a loxP-flanked neomycin resistance cassette (neor) with a triple polyadenylation signal, a full-length cDNA encoding mouse T-box 1 protein (TBX1) with a Myc epitope tag, an internal ribosomal entry site (IRES) and a green fluorescent protein coding sequence. Upon cre recombinase-mediated recombination, neor is excised and the Tbx1 cDNA is expressed under control of the beta-actin promoter. (J:146886)