Exon 3 was replaced with one with a nucleotide substitution resulting in the amino acid substitutions of arginine with aspartic acid at position 114 (R114D). Flp-mediated recombination removed the selection cassette inserted into intron 5 and a puromycin cassette inserted into intron 9. Cre-mediated recombination removed exons 6 through 9. (J:288980)