Drosophila hairy pair-rule gene regulates embryonic patterning outside its apparent stripe domains.
The hairy (h) segmentation gene of Drosophila regulates segmental patterning of the early embryo, and is expressed in a set of anteroposterior stripes during the blastoderm stage. We have used a set of h gene deletions to study the h promoter and the developmental requirements for individual h stripes. The results confirm upstream regulation of h striping but indicate that expression in the anterodorsal head domain depends on sequences downstream of the two transcription initiation sites. Surprisingly, the two anterior-most h domains appear to be dispensable for head development and embryonic viability. One partial promoter deletion expresses ectopic h, leading to misexpression of other segmentation genes and embryonic pattern defects. We demonstrate that h affects patterning outside its apparent stripe domains, supporting a model in which primary pair-rule genes act as concentration-dependent transcriptional regulators, i.e. as local morphogens.
Zoology Department, University of Oxford, England.
M
M
Lardelli
D
D
Ish-Horowicz
D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D005786:Gene Expression Regulation / Q000235:genetics; D017344:Genes, Insect / Q000235:genetics*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007301:Insect Hormones / Q000235:genetics*; D019476:Insect Proteins; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D012097:Repressor Proteins; D017385:Sequence Homology; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics
D051792:Basic Helix-Loop-Helix Proteins; D029721:Drosophila Proteins; D007301:Insect Hormones; D019476:Insect Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C489235:hairy protein, Drosophila; C061841:hairy protein, insect