Fig. 7. The GATA sequence is necessary for intestinal gene expression. The GATA sequence in the promoters of elo-6, gst-42 and D2030.5 was mutated and used to generate transgenic GFP reporter strains. (+) indicates the wild-type promoter for each gene and (GATA) indicates that one copy of the GATA motif in the promoter was mutated. Mean pixel intensity was calculated by averaging the image pixel intensity of 20 young adult hermaphrodite animals. (A) Bright-field and GFP images of wild-type and mutant strains. (B) Quantification of GFP expression indicates that the variation between lines is less than the variation between wild-type and mutant strains (P<0.001), indicating that the difference between wild-type and GATA mutant expression levels is not due to variability in the transformation procedure. There is little difference in expression between different lines formed from the same DNA construct, not only in the five lines shown here, but also for three other lines used in a different study (Y.L., unpublished).