Figure 2.

Fragments from yellow 5′ intergenic and intronic regions tested in yeast-one-hybrid (Y1H) assay. The yellow locus, including the 5′ intergenic and intronic regions from D. melanogaster, D. pseudoobscura, and D. willistoni are shown. Each locus was divided into the fragments indicated by the white boxes, plus the preceding and following gray shaded boxes (if applicable), which show the overlapping regions between neighboring fragments. The broken arrow represents transcription start site (TSS). Checkered boxes represent 5′ untranslated region (UTR) if they come before exon 1, 3′ UTR if they come after exon 2. Yellow boxes indicate yellow coding sequences. Green vertical lines indicate the start, and red vertical lines represent the end, of 5′ intergenic or intronic regions of yellow from each species. The numbers next to green and red vertical lines indicate the start and end position of 5′ intergenic and intronic regions relative to TSS. Each fragment was cloned in front of a HIS3 reporter gene, which is represented by the orange boxes. The name of each fragment is written under each schematic. * indicates fragments that were not tested with Y1H for technical reasons, as described in Materials and Methods. † indicates that the fragment was tested with only half of the available transcription factors in Y1H, again for technical reasons. mel, D. melanogaster; pse, D. pseudoobscura; will, D. willistoni.