Fig. 2. A 650 bp enhancer is sufficient to drive the C15 dorsal-stripe pattern. (A) The C15 gene (yellow arrow) is located in the 93DE homeobox gene cluster (green arrows) (Jagla et al., 2001), which also contains predicted genes (pink boxes). Several overlapping DNA fragments comprising approximately 30 kb of 5', 3' and intronic (I) DNA of the C15 gene were tested in lacZ reporter assays, some of which were capable of activating lacZ expression in blastoderm embryos (blue lines). (B-E) Embryos hybridized with lacZ probes. (B) I-2-lacZ shows a lacZ pattern identical to the endogenous C15 pattern. (C) I-2-4-lacZ shows a broader pattern, suggesting that a negative element is missing. (D) 650-3 shows a lacZ pattern like that of I-2. (E) 350-2 shows weaker lacZ expression than the 650-3.