<p>(a) PCR identification of sgRNA:Cas9-mediated site-specific cleavage of the endogenous <i>ApoE</i>, <i>B2m</i>, <i>Prf1</i>, and <i>Prkdc</i> loci. The genetic modification analysis was performed by PCR amplification of the targeted fragment in the <i>ApoE</i>, <i>B2m</i>, <i>Prf1</i>, and <i>Prkdc</i> in 25 founder rats (#16∼40) derived from co-microinjection of a mixture of dual sgRNAs for each genes as described in Table S2 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089413#pone.0089413.s001" target="_blank">File S1</a>. Primer used for PCR amplication was described in Table S3 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089413#pone.0089413.s001" target="_blank">File S1</a>. Additionally, founder #36, #38 had a larger deletion in the <i>ApoE</i>, the primer <i>ApoE</i>-NS2 and <i>ApoE</i>-NAS2 used for amplification. Founder #38 had a larger deletion in the <i>B2m</i>, the primer <i>B2m</i>-S2 and <i>B2m</i>-AS2 used for amplification. (b) Detection of Cas9:sgRNA-mediated site-specific cleavage of the endogenous <i>ApoE</i>, <i>B2m</i>, <i>Prf1</i>, and <i>Prkdc</i> by T7EN1 cleavage assay. PCR products from (a) were subjected to T7EN1 cleavage assay as described in material and methods.</p
