Th^{tm1.1(flpo)Awar}

KOMP targeted ES cell clone Th_C09 which has been genetically modified such that the Engrailed splice acceptor (SA) followed by ires-lacZ cassettes have been inserted in the intron following exon 6 of the Th gene was used for dual recombinase-mediated cassette exchange to reengineer the lacZ allele into the Th-2A-Flpo. A targeting vector that included exons 7 to 13 of Th coding sequence, the autocatalytic peptide P2A, Flpo, WPRE sequence, a bovine growth hormone polyadenylation signal (bGH pA) followed by a puromycin selection cassette flanked by rox sites. The targeting construct was electroporated into KOMP ES cells in combination with the plasmid pDIRE and selected for puromycin resistance. ES cell clone with correct integration at the Th locus and a successful RMCE was generate chimeric mice.The puromycin selection cassette was later removed by crossing to CAG-Dre transgenic mice (J:266806)