Fig. 7. Mutation of GATA sites eliminates HCEK activity in transgenic mice. Left: each of the four GATA sites was mutated within IM-lacZ-XB. Mutated GATA sequences (Gm1–Gm4) are shown under the wild-type sequences. Middle: the incidence of β-gal-expressing embryos bearing each construct with a mutated GATA site is shown in the same way as described in the legend to Figure 4. Right: the structures of IM-lacZ-XB and its derivatives are depicted. Each mutated GATA site was marked with a small x within the XB region. The constructs that retain enhancer activity are marked with +, and those without activity are marked with –. For abbreviations, see legend to Figure 4.