A Versatile Transgenic Allele for Mouse Overexpression Studies

Mamm Genome. 2015 Dec;26(11-12):598-608. doi: 10.1007/s00335-015-9602-y. Epub 2015 Sep 14.


For the analysis of gene function in vivo, gene overexpression in the mouse provides an alternative to loss-of-function knock-out approaches and can help reveal phenotypes where compensatory mechanisms are at play. Furthermore, when multiple lines overexpressing a gene-of-interest at varying levels are studied, the consequences of differences in gene dosage can be explored. Despite these advantages, inherent shortcomings in the methodologies used for the generation of gain-of-function transgenic mouse models have limited their application to functional gene analysis, and the necessity for multiple lines comes at a significant animal and financial cost. The targeting of transgenic overexpression constructs at single copy into neutral genomic loci is the preferred method for the generation of such models, which avoids the unpredictable outcomes associated with conventional random integration. However, despite the increased reliability that targeted transgenic methodologies provide, only one expression level results, as defined by the promoter used. Here, we report a new versatile overexpression allele, the promoter-switch allele, which couples PhiC31 integrase-targeted transgenesis with Flp recombinase promoter switching and Cre recombinase activation. These recombination switches allow the conversion of different overexpression alleles, combining the advantages of transgenic targeting with tunable transgene expression. With this approach, phenotype severity can be correlated with transgene expression in a single mouse model, providing a cost-effective solution amenable to systematic gain-of-function studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Gene Expression*
  • Genes, Reporter
  • Green Fluorescent Proteins / biosynthesis
  • Green Fluorescent Proteins / genetics
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Organ Specificity
  • Promoter Regions, Genetic
  • Transgenes*


  • enhanced green fluorescent protein
  • Green Fluorescent Proteins