Animal model and method for studying gene-gene interactions

A transgenic, non-human animal whose genome comprises:

• a first gene comprising an exon;
• a second gene comprising an exon;
• a first reporter gene and a second reporter gene integrated into the first gene, at positions flanking the exon of the first gene, wherein the first reporter gene and the second reporter gene are in opposite orientations, wherein the first reporter gene encodes a first fluorescent polypeptide label, and the second reporter gene encodes a second fluorescent polypeptide label;
• a first recombinase target site and a second recombinase target site, in opposite orientation, and integrated into the first gene at positions flanking the first reporter gene and the second reporter gene, respectively;
• a third reporter gene and a fourth reporter gene integrated into the second gene at positions flanking the exon of the second gene, wherein the third reporter gene and the fourth reporter gene are in opposite orientations, wherein the third reporter gene encodes a third fluorescent polypeptide label, and the fourth reporter gene encodes a fourth fluorescent polypeptide label, and wherein the first, second, third, and fourth fluorescent polypeptide labels are distinct from each other;
• and
• a third recombinase target site and a fourth recombinase target site, in opposite orientation, and integrated into the second gene at positions flanking the third reporter gene and the fourth reporter gene, respectively, and
• a nucleic acid sequence integrated at a separate locus, wherein the nucleic acid encodes an inducible recombinase.