Hoxd13 and regions XI and XII were deleted via trans-allelic meiotic recombination (TAMERE). The deletion was accomplished by recombination of a single loxP site in the intergenic region between Evx2 and Hoxd13 that had replaced region XII (Evx2/Hoxd13tm3.1Ddu) and a single loxP on the opposite chromosome in the intergenic region between Hoxd12 and Hoxd13 (Hoxdtm3Ddu). (J:80084)