Fig 6. Production of excised Poldip2 mice.

New floxed Poldip2 mice were crossed with a transgenic Cre deleter to produce animals with a constitutively excised Poldip2 allele. These mice were then backcrossed with wild type C57BL/6J to remove the Cre transgene and eliminate mosaicism. A: Design of a genotyping method for the excised Poldip2 allele. The genomic maps show the annealing sites of three primers and corresponding amplicons from wild type (top, green) and excised alleles (bottom, red). The 641 bp region around exon 4 (E4) in wild type, highlighted in dark blue, is replaced in the excised allele by a 95 bp insert (red box) that includes the remaining 34 bp loxP site. The forward primer (p14) anneals to intron 3 and the reverse primers either to exon 4 (p15) or to the loxP insert (p16), ensuring allele specificity. B: Representative agarose gel, following PCR with the three primers above, revealing the presence of viable homozygous pups at weaning age.