The targeting vector was designed to insert (from 5' to 3') an internal ribosomal entry site (IRES) fused to an enhanced green fluorescent protein (EGFP) and a self-excising loxP-flanked ACN cassette into exon 11 of the X-linked forkhead box P3 (Foxp3) gene. The ACN cassette contained a neomycin resistance (Neo) gene and a testes-specific angiotensin-converting enzyme promoter-driven Cre recombinase gene (tACE-Cre). The construct was electroporated into C57BL/6-derived Bruce-4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into FVB/N blastocysts and chimeric males were bred to C57BL/6J females. The resulting Foxp3GFP mice were maintained on a C57BL/6J background.
This reporter mouse model is deposited at The Jackson Laboratory (Jax stock#018628).