Pik3ca^tm1Gne

A loxP site was in upstream of the wild-type exon 20, which was followed by a polyadenylation sequence, an FRT-flanked neo cassette, 4x transcriptional STOP, a loxP site and a modified exon 20. The modified exon 20 contained an A to G transition results in the amino acid substitution of arginine for histidine at position 1047 (H1047R). Flp-mediated recombination removed the FRT-flanked neo cassette. Cre-mediated recombination is required to remove the wild-type exon 20 and allow for expression of the modified exon 20. (J:193377)