The targeting vector contains, from 5' to 3', a partial Slc32a1 sequence spanning exon 1 (with an FRT3 site in intron 1) through part of exon 2 up to (but not including) the endogenous stop codon, a T2A sequence, a flpO recombinase gene (a codon-optimized FLPe gene), a BHG polyA sequence, an AttB site, a PGK-neomycin cassette, an FRT5 site, an mRNA splice acceptor sequence, the 3' portion of the hygromycin gene (Hygro2) with SV40 polyA signal, and an AttP site. PhiC31-mediated recombination removed the AttB/AttP-flanked sequence and replaced it with the recombined AttB/AttP site (AttL). (J:101977)