Southern blot analysis of tail DNA from wild-type mice and mice homozygous (H/H), hemizygous (H/Y), heterozygous (H/+) for the R333Q-hFIX mutation. Tail DNA was digested with EcoRV and hybridized to the 730-bp probe. Lanes 1 and 7 show a 17.2-kb band from a wild-type female (WT nonhemophilic) and male (WT nonhemophilic) mouse, respectively. Lanes 3 to 5 show a 4.7-kb band from female R333Q-hFIX mice (H/H, homozygous hemophilic females) and lanes 6 and 8 also show the 4.7-kb band from male mice that are hemizygous for the mutation (H/Y, hemizygous hemophilic males). Lane 2 shows 4.7-kb and 17.2-kb bands from the heterozygous mouse (H/+ nonhemophilic carrier female).