Two loxP sequences flanking conserved non-coding sequence 2 (CNS2 (Rr124)) in intron 1, as well as an FRT site flanked neomycin resistance gene cassette were inserted by homologous recombination. In addition, an EGFP cassette was inserted in-frame into the first coding exon. The selection cassette was removed by flp-mediated recombination. (J:156942)