En1^{tm1.1(dreo)Pjen}

The mammalian codon-optimized bacteriophage D6 site-specific recombinase gene (dreo) with a 5' a viral 2A oligopeptide (T2A) that mediates ribosomal skipping replaced the stop codon and 41 bp of the 3' UTR in exon 2 without altering the coding sequence. phiC31-mediated recombination removed the neomycin resistance cassette inserted downstream of the recombinase gene. (J:232241)