The transgene targeted to the locus contains a splice acceptor flanked puro cassette, CAG promoter, floxed stop cassette, FRT-flanked stop cassette, the halorhodopsin from the halophilic bacterium Natronomas pharaonis modified with an N-terminal signal peptide and a C-terminal endoplasmic reticulum export sequence fused in-frame with an enhanced yellow fluorescent protein (eNpHR3-EYFP), and a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE; to enhance the mRNA transcript stability). Flp-mediated recombination removed the FRT-flanked stop cassette. (J:104881)