title: Regulative feedback in pattern formation: towards a general relativistic theory of positional information.
abstract: Positional specification by morphogen gradients is traditionally viewed as a two-step process. A gradient is formed and then interpreted, providing a spatial metric independent of the target tissue, similar to the concept of space in classical mechanics. However, the formation and interpretation of gradients are coupled, dynamic processes. We introduce a conceptual framework for positional specification in which cellular activity feeds back on positional information encoded by gradients, analogous to the feedback between mass-energy distribution and the geometry of space-time in Einstein's general theory of relativity. We discuss how such general relativistic positional information (GRPI) can guide systems-level approaches to pattern formation.
authors.affiliation: Laboratory for Development and Evolution, University Museum of Zoology, Department of Zoology, University of Cambridge, Cambridge, UK. jj231@cam.ac.uk
authors.forename: Johannes
authors.initials: J
authors.lastname: Jaeger
authors.forename: David
authors.initials: D
authors.lastname: Irons
authors.forename: Nick
authors.initials: N
authors.lastname: Monk
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics; D025461:Feedback, Physiological; D017344:Genes, Insect; D053823:Hedgehog Proteins / Q000235:genetics / Q000502:physiology; D008954:Models, Biological; D013598:Systems Theory; D014714:Vertebrates / Q000196:embryology / Q000235:genetics
chemical_list: D053823:Hedgehog Proteins