AbstractPatterns ofdecapentaplegic (dpp)transcripts derived from the intact gene were compared to the patterns of transcripts generated by partialdpptransgenes in Drosophila embryos. Sequences closest to thedppcoding regions, thedpphin region, were sufficient to expresslacZ‐tagged mRNA in patterns indistinguishable from the patterns of endogenousdppexpression in the dorsal and terminal cells at the blastoderm stage, in the dorsal ectoderm during germ band elongation, and in narrow stripes of ectodermal cells along the dorsal edge of the ectoderm and at the boundary between the lateral and ventral neurogenic regions during germ band shortening. The latter pattern of expression responded to the segment polarity genesnakedandwingless. However, thesedppsequences were not sufficient to drivelacZ‐tagged mRNA expression in other cells normally expressingdpp, including cells in the gnathal segments, the clypeolabrum, the foregut, the midgut visceral mesoderm, and the hindgut. Two separate regulatory regions were found in thedpphin region. A 479 bp region upstream of the promoter was necessary for the segmented pattern of expression in the lateral ectoderm and for expression in the midgut endoderm. Cis‐acting elements in the 2 kbp second intron directed expression in the dorsal and terminal regions of the blastoderm, acted on a heterologous promoter, the P‐element promoter, and responded to pattern information derived from the maternal effect dorsal/ventral patterning genes. © 1994 Wiley