Fezf1^{tm1.1(cre/folA)Hze}

ES cells previously targeted with a T2A-Cre vector immediately downstream of the Fez family zinc finger 1 translational STOP codon were re-targeted with a "T2A-hDHFR/Cre" vector and a FLP-expressing plasmid to facilitate recombination. Correctly re-targeted ES cells had (from 5' to 3') a partial Fezf1 intron 3 sequence containing an frt3 site, a partial Fezf1 exon 4 sequence up to (but not including) the endogenous stop codon, a T2A cleavage sequence that is in-frame with the Fezf1 coding sequence, a dCre fusion gene (described below) that is in-frame with the Fezf1 coding sequence, a bovine growth hormone polyA sequence, an AttB sequence, a PGK-hygromycin-SV40polyA cassette (with an mRNA spice donor-frt5 site-mRNA spice acceptor in the hygromycin gene), and an AttP sequence. The dCre fusion gene (also called destabilized Cre, DHFR/Cre or ecDHFR/Cre) is Cre recombinase fused at its N terminus to the first 159 amino acids of the Escherichia coli K-12 strain chromosomal dihydrofolate reductase gene (DHFR or folA) harboring the G67S mutation and modified to also include the R12Y/Y100I destabilizing domain mutations. PhiC31-mediation recombination removed the AttB/AttP-flanked sequence and replaced it with the recombined AttB/AttP site (AttL). (J:146821)