Modeling segmental patterning in Drosophila: Maternal and gap genes.
We propose a new mathematical model describing the establishment of maternal and gap proteins segmental patterning along the antero-posterior axis of the Drosophila early embryo. This model is based on experimental data and, without recurring to pre-defined activation thresholds, predicts qualitatively and quantitatively the expression patterns of the maternal and gap proteins, as well as the expression patterns of proteins resulting from mRNA ectopic expression and from some loss-of-function mutations. We conclude that the gap genes segmental patterning and consequent spatial organization of the embryo is determined by three main factors: (1) the initial positioning of the maternal bicoid and torso mRNA inside the egg, and subsequent diffusion of the corresponding proteins; (2) the structure of the genetic regulatory network; (3) the role of conservation laws in the establishment of steady and non-uniform spatial distributions of non-diffusing proteins.
Alves
Filipa
F
Non-Linear Dynamics Group, Instituto Superior Técnico, Department of Physics, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. filipa@sd.ist.utl.pt
Dilão
Rui
R
D000818:Animals; D019521:Body Patterning / Q000235:genetics*; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins; D004527:Egg Proteins / Q000096:biosynthesis / Q000235:genetics; D020690:GTPase-Activating Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics; D008957:Models, Genetic; D009154:Mutation; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics
D029721:Drosophila Proteins; D004527:Egg Proteins; D020690:GTPase-Activating Proteins; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; C056478:bcd protein, Drosophila