Ectopic germline recombination activity of the widely used Foxp3‐YFP‐Cre mouse: a case report

• DOI: 10.1111/imm.13153
• Publication Date: 2019-11-12T04:29:53Z
• Authors: Dan Wu; Qing Huang; Paul C. Orban; Megan K. Levings
• Keywords: Mice, Knockout; Recombination, Genetic; Genotype; Integrases; Forkhead Transcription Factors; Mice, Transgenic; Polymerase Chain Reaction; T-Lymphocytes, Regulatory; Receptor, Insulin; Luminescent Proteins; Phenotype; Bacterial Proteins; Genes, Reporter; Animals; Cell Lineage; Promoter Regions, Genetic; Crosses, Genetic

Regulatory T (Treg) cell-specific deletion of a gene interest is procedure widely used to study mechanisms controlling Treg development, homeostasis and function. Accordingly, several transgenic mouse lines have been generated that bear the Cre recombinase under control Foxp3 promoter either as random transgene insertion or knocked into endogenous locus, with Foxp3YFP-Cre strain mice being one most used. In an attempt generate cells lacked expression insulin receptor (Insr), we crossed Insrfl/fl mice. Using conventional two-band PCR genotyping method found offspring genotypes did not correspond expected Mendelian ratios. We therefore developed quantitative PCR-based investigate possible ectopic recombination outside lineage. With this ~50% F1 -generation showed evidence ~10% F2 had germline activity leading high frequency global Insr deletion. Use enabled accurate selection without only desired Our data highlight need use methods allow for assessment driven by allele, particularly when studying genes are systemically expressed.