A hygromycin selection cassette and DR-GFP reporter, were inserted into the locus via homologous recombination. The DR-GFP reporter consists of , consisting of two mutated GFP genes, SceGFP, which is disrupted at an LweI restriction site by the 18-bp recognition site for the I-SceI endonuclease, and iGFP, which is truncated at both the 5' and 3' ends. Following homology directed repair a functional GFP gene expressed under the control of a beta-actin promoter and CMV enhancer is generated.