This transgene contains the coding sequence for enhanced green fluorescent protein (EGFP), followed by a polyadenylation signal, inserted into a mouse genomic bacterial artificial chromosome (BAC) that contains the aldehyde dehydrogenase 1 family, member L1 (Aldh1l1, formerly Fthfd) gene at the ATG transcription initiation codon of that gene so that expression of the reporter mRNA/protein is driven by the regulatory sequences of the mouse gene. (J:100256)