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

The targeting vector containa, from 5' to 3', a partial intron 2 through intron 3 sequence containing an FRT3 site in intron 3, a partial exon 4 sequence up to and including the endogenous stop codon, an internal ribosome entry site 2 sequence (IRES2; allows translation initiation in the middle of an mRNA sequence) that is in-frame with the coding sequence, a dgCre fusion gene (described below) that is in-frame with the coding sequence, a bovine growth hormone polyA signal, an AttB site, a PGK-Neo-polyA cassette, an FRT5 site, an mRNA splice acceptor, the 3' portion of the hygromycin gene with SV40 polyA signal, and an AttP site. The dgCre fusion gene is an enhanced green fluorescent protein/Cre recombinase fusion gene with an N terminal fusion of 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 integrase-mediated recombination removed the AttB/AttP-flanked sequences. Although designed to be trimethoprim-inducible, the donating investigator reports the cre expression/activity pattern looks the same before and after TMP induction. No EGFP is detected with or without induction. (J:227758)