The targeted construct inserted into the locus a splice acceptor, CAG promoter, floxed stop cassette, mouse cDNA encoding an amino acid substitution of alanine for serine at position 112 (S112A), FRT-flanked IRES and EGFP reporter gene and a polyadenylation sequence. Flp-mediated recombination removed the neomycin resistance cassette. (J:220179)