The transgene was designed with (from 5' to 3') with a mouse NK2 homeobox 5 locus (Nkx2-5) promoter/enhancer sequence (2.1 kbp enhancer fragment from the regulatory region ~9.5 kbp upstream of the translation start site and the 0.5 kbp base promoter sequence), an enhanced green fluorescent protein sequence (eGFP) and an SV40 polyA sequence. (J:233946)