Gt(ROSA)26Sor^{tm13.1(CAG-HRP)Luo}

A cassette incorporating CAG-FRT-stop-FRT(FSF)-loxP-stop-loxP(LSL)-SP-hemagglutinin (HA)-HRPtm-WPRE-bGHpolyA flanked by attB sites is introduced to the first intron of Gt(ROSA)26Sor by integrase-mediated transgenesis. The CAG promoter, FSF, and LSL cassettes (incorporating poly(A) transcriptional terminal signals and translational stop codons in all three reading frames from the Ai65 targeting vector) enable high levels of HRP expression gated by Flp and Cre recombinases. The HRP coding DNA sequence was preceded by an IgK signal peptide (SP) and a hemagglutinin (HA) tag and followed by a PDGFRbeta transmembrane (tm) domain and a short intracellular domain with Kir2.1 (Kcnj2) trafficking and endoplasmic reticulum (ER) transport signals separated by Gly-Ser-Gly (GSG) linkers. The whole coding sequence was codon optimized and followed by a woodchuck hepatitis virus posttranscriptional regulatory element (WPRE) and a bovine growth hormone polyadenylation signal (bGHpolyA). Flp-mediated recombination removed the FRT-flanked stop cassette. (J:329532)