Hcrt^{tm1.1(flpo)Ksak}

A targeting construct in which the MC1 promoter-driven diphtheria toxin gene, a 5.44 kb fragment at the 5' site, codon-optimized for mammalian expression Flp recombinase, including a nuclear localization signal cDNA fused to EGFP with the T2A peptide sequence, a Pgk-1 promoter-driven neomycin phosphotransferase gene (neo) flanked by two Dre recognition target (rox) sites was used for homologous recombination in ES cells to insert EGFP-2A-Flp just behind the translational initiation site of the hypocretin gene (Hcrt) in-frame. The neo cassette was removed in the ES cells by Dre recombination. This allele is a null allele confirmed by immunohistochemical studies. (J:277436)