Pitfalls of PCR-Based Strategy for Genotyping <i>Cre-Loxp</i> Mice

The study addressed the difficulties of using PCR-based methods for genotyping cre-loxP mice, particularly in distinguishing between wild-type, lox, and deletion alleles. It focused on mice with a conditional knockout of the igf1r gene in the CNS, using a nestin-cre transgenic line, and found that cre-mediated recombination could occur in non-target tissues like tails, potentially causing misgenotyping. A three-primer PCR approach was suggested to improve accuracy by detecting all alleles and assessing recombination efficiency. The research emphasized the need to consider cre expression in non-target tissues, which could lead to unintended gene deletions and impact the interpretation of gene function.