Fen1^tm3Klng

Site directed mutagenesis followed by homologous recombination was used to modify the coding sequence of exon 2 creating amino acid substitutions at positions 343 and 344 of glycine and alanine, respectively, for phenylalanine (F343G and F344A). This mutation alters two amino acids critical for protein protein interaction. A neo cassette was also inserted downstream of exon 2 for selection purposes. (J:138901)