Embryonic expression patterns of the drosophila decapentaplegic gene: Separate regulatory elements control blastoderm expression and lateral ectodermal expression

Abstract

Patterns of decapentaplegic (dpp) transcripts derived from the intact gene were compared to the patterns of transcripts generated by partial dpp transgenes in Drosophila embryos. Sequences closest to the dpp coding regions, the dpp hin region, were sufficient to express ZacZ-tagged mRNA in patterns indistinguishable from the patterns of endogenous dpp expression 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 genes naked and wingless. However, these dpp sequences were not sufficient to drive ZucZ-tagged mRNA expression in other cells normally expressing dpp, including cells in the gnathal segments, the clypeolabrum, the foregut, the midgut visceral mesoderm, and the hindgut. Two separate regulatory regions were found in the dpp hin 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. 0 1994 Wiley-Liss, Inc.

Drosophila Jun kinase regulates expression of decapentaplegic via the ETS-domain protein Aop and the AP-1 transcription factor DJun during dorsal closure.

“…An appraisal of the role of dpp in dorsal closure has been precluded by the fact that dpp plays a vital role earlier in dorsoventral patterning (Irish and Gelbart 1987;Padgett et al 1987;St. Johnson and Gelbart 1987;Ferguson and Anderson 1992;Jackson and Hoffmann 1994). However, we note that dpp is expressed in the leading edge cells during dorsal closure .…”

Drosophila Jun relays the Jun amino-terminal kinase signal transduction pathway to the Decapentaplegic signal transduction pathway in regulating epithelial cell sheet movement.

“…Because several members of the Dpp signal transduction pathway also exhibit this phenotype (Brummel et al 1994;Nellen et al 1994;Penton et al 1994;Arora et al 1995;Grieder et al 1995;Letsou et al 1995;Ruberte et al 1995;Staehlong-Hampton et al 1995), we tested whether dpp expression was affected in Djun mutant embryos. In wild-type embryos, dpp is expressed in a complex pattern that includes expression in the dorsal-most cells of the epidermis during germ-band retraction (St. Johnston and Gelbart 1987;Jackson and Hoffmann 1994;see Fig. 4A1,BI).…”

Hedgehog and Decapentaplegic instruct polarized growth of cell extensions in theDrosophilatrachea

“…Dpp expression at stage 14, as monitored with the dpp-lacZ reporter, manifested as a longitudinal stripe at the leading edge of the DE, mimicking the pattern of dpp mRNA expression (Fig. 3C) (see Jackson and Hoffmann, 1994). The tip of the DB was located two or three cells behind the region of dpp-lacZ expression (Fig.…”