Sox2^{em1.1(Snrpn-tdTomato)Jae}

CRISPR/cas9 endonuclease-mediated genome editing is used to target the super enhancer (SE) sequences ~100 kb distal of the SRY (sex determining region Y)-box 2 locus (Sox2) on chromosome 3, as well as Snrpn::tdTomato::WPRE::BHGpA::loxP-PGK-Puro-loxP sequences (encoding the minimal Snrpn promoter, the tdTomato fluorescent protein, a WPRE sequence, a BGH polyadenylation sequence and a loxP-flanked PGK-Puro selection cassette). Junction PCR-SNP analyses identified ES cells with the S2T sequences (Snrpn::tdTomato::WPRE::BHGpA) inserted into the Sox2 SE on the 129 chromosome. Those ES cells were transfected with a Cre recombinase-expressing plasmid to remove the PGK-Puro, (J:282716)