Pvalb^{tm4.1(flpo)Hze}

ES cells already targeted with a T2A-Cre vector immediately downstream of the parvalbumin translational STOP codon, were re-targeted with a "T2A-Flpo" vector and a FLP-expressing plasmid to facilitate recombination. Correctly targeted ES cells had (from 5' to 3') a three amino acid linker sequence, an frt3 site within Pvalb intron 3, a partial Pvalb exon 4 sequence up to (but not including) the endogenous stop codon, a T2A sequence in-frame with the Pvalb coding sequence, a FlpO recombinase gene (a codon-optimized FLPe modified for translation in mammalian cells and higher recombination efficiency), the Pvalb 3' UTR sequence from exon 4, an attB site, a PGK-hygromycin-SV40polyA cassette (with a frt5 site in the hygromycin gene), and an attP site. Correctly targeted ES cells were injected into recipient blastocysts. The resulting chimeric animals were bred to PhiC31-expressing mice (C57BL/6J congenic background; see JAX Stock No. 007743) to delete the attB/attP-flanked PGK-hygromycin-polyA cassette. Heterozygous mice have an FlpO recombinase expression pattern in the brain similar to endogenous Pvalb expression. (J:197021, J:219930)