Fig. 8. The A. gambiae sog enhancer directs restricted expression in transgenic D. melanogaster embryos. (C) The Cluster-Draw program (Zinzen et al., 2006) identified several potential Dorsal binding clusters in the A. gambiae sog locus. (D) The best cluster is located at the 3' end of intron 1 (top schematic). Different genomic DNA fragments (numbered pink bars) were attached to a lacZ reporter gene, inserted into the D. melanogaster genome (lower schematic) and expressed in transgenic embryos. Only fragments 1 and 2 exhibited any activity as measured by in situ hybridization with a lacZ antisense RNA probe. (A,B) Lateral and ventral views, respectively, of embryos after staining with the larger fragment (the fragment 1-lacZ fusion gene).