Kras^em3Ldow

CRISPR/Cas9 genome editing is used to alter embryonic stem (ES) cells from Krastm4Tyj mutant mice. The original Kras mice have a G12D point mutation in exon 2 of the gene and a loxP ite flanked STOP element in intron 1. Guide RNAs targeting the KrasG12D site and codon 13, an ssODN template and the Cas9 nuclease are used to restore codon 12 to wildtype glycine and introduce a p.G13D mutation associated with coloretal cancer. (J:299292)