Disruption of Rag2 gene in rat SSCs. (A) The XTN pair targets early in the single coding exon of Rag2 gene. XTN binding sites are capitalized, the Rag2 start codon is shown in boldface font and underlined, the MseI site utilized for genotyping is marked. (B) Alignment of clones to the wild type reference sequence. Reference sequence is underlined, the XTN binding sites are shown in uppercase, mutations are shown in bold font and Rag2 start codon is in bold font and underlined. Clone E10 contains a single nucleotide deletion, clone A05 contains a two nucleotide deletion.