These RosaGli3TFlag c/c mice contain a floxed-neomycin resistance (neo) cassette and polyadenylation signal, cDNA encoding a FLAG-tagged GLI-Kruppel family member (Gli3) repressor gene, an internal ribosome entry site (IRES), and a Venus yellow fluorescent protein (YFP) under control of the ubiquitous Gt(ROSA)26Sor locus. Breeding these mutant mice to mice that express Cre-recombinase will also result in Floxed-neo-stop excision. When these mice are crossed to mice containing Cre-recombinase under direction of a paired related homeobox 1 (Prrx1) promoter (see Stock No. 005584), active in early limb mesenchyme, the mice produce Gli3TFlag at levels that are comparable with the endogenous protein. Mice exhibited a variety of limb defects including a variable preaxial forelimb polydactyly, limb truncation, and reduced mineralization. These mice may be useful for understanding Sonic hedgehog signaling and identifying targets of Gli3 action in developing mouse limbs. The Jackson Laboratory 2024, used with permission.