TitleDual regulation by the Hunchback gradient in the Drosophila embryo.
Publication TypeJournal Article
Year of Publication2008
AuthorsPapatsenko, D, Levine, MS
JournalProc Natl Acad Sci U S A
Date Published2008 Feb 26
KeywordsAnimals, Body Patterning, Computer Simulation, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Gene Expression Regulation, Developmental, Kruppel-Like Transcription Factors, Models, Biological, Transcription Factors

The regulation of segmentation gene expression is investigated by computational modeling using quantitative expression data. Previous tissue culture assays and transgene analyses raised the possibility that Hunchback (Hb) might function as both an activator and repressor of transcription. At low concentrations, Hb activates gene expression, whereas at high concentrations it mediates repression. Under the same experimental conditions, transcription factors encoded by other gap genes appear to function as dedicated repressors. Models based on dual regulation suggest that the Hb gradient can be sufficient for establishing the initial Kruppel (Kr) expression pattern in central regions of the precellular embryo. The subsequent refinement of the Kr pattern depends on the combination of Hb and the Giant (Gt) repressor. The dual-regulation models developed for Kr also explain some of the properties of the even-skipped (eve) stripe 3+7 enhancer. Computational simulations suggest that repression results from the dimerization of Hb monomers on the DNA template.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.