FIG. 6.

Functional conservation of the D. virilis sim early regulatory region. The stretch of the D. virilis sim gene corresponding to the 2.8-kb D. melanogaster sim early regulatory region was sequenced and functionally assayed. At the top is a representation of the D. virilis sim gene showing the location of exon 2 (box with coding sequence filled and 5′ UTR unfilled) and the approximate location of PE. Below are the locations of the D. virilis smvs and the region sequenced. The D. virilis 4.6-kb NsiI-NcoI fragment was fused to lacZ in the CaSpeR-AUG-βgal P-element vector, introduced into D. melanogaster germline DNA, and assayed for mesectodermal transcription by hybridization to a lacZ RNA probe. The stage 7 embryo shows strong mesectodermal lacZ stripes. Ventral view is shown; anterior is to the left.