Dendra2 (a green to red irreversibly photoswitchable monomeric fluorescent protein derived from octocoral Dendronephthya sp.) fused to the mitochondrial targeting signal of subunit VIII of cytochrome c oxidase (mito-Dendra2), bovine growth hormone (bGH) polyadenylation signal, and an FRT-flanked neomycin cassette were introduced to Gt(ROSA)26Sor downstream of a CAG (CMV-beta-actin) promoter and loxP-flanked termination signal. Flp-mediated recombination removed the neo cassette and cre-mediated recombination excised the floxed termination cassette. (J:183306, J:189358)