title: Quantifying the Gurken morphogen gradient in Drosophila oogenesis.
abstract: Quantitative information about the distribution of morphogens is crucial for understanding their effects on cell-fate determination, yet it is difficult to obtain through direct measurements. We have developed a parameter estimation approach for quantifying the spatial distribution of Gurken, a TGFalpha-like EGFR ligand that acts as a morphogen in Drosophila oogenesis. Modeling of Gurken/EGFR system shows that the shape of the Gurken gradient is controlled by a single dimensionless parameter, the Thiele modulus, which reflects the relative importance of ligand diffusion and degradation. By combining the model with genetic alterations of EGFR levels, we have estimated the value of the Thiele modulus in the wild-type egg chamber. This provides a direct characterization of the shape of the Gurken gradient and demonstrates how parameter estimation techniques can be used to quantify morphogen gradients in development.
authors.affiliation: Department of Chemical Engineering and Lewis-Sigler Institute for Integrative Genomics, Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Lea A
authors.initials: LA
authors.lastname: Goentoro
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Reeves
authors.forename: Craig P
authors.initials: CP
authors.lastname: Kowal
authors.forename: Luigi
authors.initials: L
authors.lastname: Martinelli
authors.forename: Trudi
authors.initials: T
authors.lastname: Schüpbach
authors.forename: Stanislav Y
authors.initials: SY
authors.lastname: Shvartsman
mesh_terms: D000818:Animals; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D008024:Ligands; D008954:Models, Biological; D009866:Oogenesis / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D016211:Transforming Growth Factor alpha / Q000235:genetics / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins; D008024:Ligands; D016211:Transforming Growth Factor alpha; C083730:grk protein, Drosophila