Hbb^{tm2(HBG1,HBD,HBB*)Ryan}

A 4.7 kb human A gamma globin (HBG1) gene fragment (GenBank id: U01317: 38,066-43,728), a 2.9 kb human delta globulin gene fragment (HBD, U01317: 54,336-57,279), a 4.1 kb human beta globin (HBB, U01317:61,320-65,426) gene fragment, and a floxed pgk-hygromycin cassette replaced the Hbb-b1 and Hbb-b2. The HBB gene fragment contained a single G to A mutation in the first base of intron 1 destroying the normal splice donor site and creating a null allele. The switch from expression of HBG1 to expression of HBB is also delayed until after birth by this point mutation. (J:148521)