title: Dynamical analysis of regulatory interactions in the gap gene system of Drosophila melanogaster.
abstract: Genetic studies have revealed that segment determination in Drosophila melanogaster is based on hierarchical regulatory interactions among maternal coordinate and zygotic segmentation genes. The gap gene system constitutes the most upstream zygotic layer of this regulatory hierarchy, responsible for the initial interpretation of positional information encoded by maternal gradients. We present a detailed analysis of regulatory interactions involved in gap gene regulation based on gap gene circuits, which are mathematical gene network models used to infer regulatory interactions from quantitative gene expression data. Our models reproduce gap gene expression at high accuracy and temporal resolution. Regulatory interactions found in gap gene circuits provide consistent and sufficient mechanisms for gap gene expression, which largely agree with mechanisms previously inferred from qualitative studies of mutant gene expression patterns. Our models predict activation of Kr by Cad and clarify several other regulatory interactions. Our analysis suggests a central role for repressive feedback loops between complementary gap genes. We observe that repressive interactions among overlapping gap genes show anteroposterior asymmetry with posterior dominance. Finally, our models suggest a correlation between timing of gap domain boundary formation and regulatory contributions from the terminal maternal system.
authors.affiliation: Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794-3600, USA.
authors.forename: Johannes
authors.initials: J
authors.lastname: Jaeger
authors.forename: Maxim
authors.initials: M
authors.lastname: Blagov
authors.forename: David
authors.initials: D
authors.lastname: Kosman
authors.forename: Konstantin N
authors.initials: KN
authors.lastname: Kozlov
authors.lastname: Manu
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Myasnikova
authors.forename: Svetlana
authors.initials: S
authors.lastname: Surkova
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Vanario-Alonso
authors.forename: Maria
authors.initials: M
authors.lastname: Samsonova
authors.forename: David H
authors.initials: DH
authors.lastname: Sharp
authors.forename: John
authors.initials: J
authors.lastname: Reinitz
mesh_terms: D000818:Animals; D001756:Blastoderm / Q000502:physiology; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D005260:Female; D020690:GTPase-Activating Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology*; D008957:Models, Genetic; D015053:Zygote / Q000502:physiology
chemical_list: D020690:GTPase-Activating Proteins