DV boundary formation of the Wing imaginal disc
Taxon: D. melanogaster
Process: Wing Imaginal disk | Development
Submitter: D. Thieffry
Supporting paper: González, Aitor and Chaouiya, Claudine and Thieffry, Denis (2006). Dynamical Analysis of the Regulatory Network Defining the Dorsal–Ventral Boundary of the Drosophila Wing Imaginal Disc. Genetics. 10.1534/genetics.106.061218
| Model file(s) | Description(s) |
|---|---|
| dv_boundary_wing_disk_model.zginml | Regulatory graph for the four cells |
| ap-1_else-0_wt.zginml | Apterous dependent network |
Summary:
The larval development of the Drosophila melanogaster wings is organized by
the protein Wingless, which is secreted by cells adjacent to the
dorsal–ventral (DV) boundary. Two signaling processes acting between the
second and early third instars and between the mid- and late third instar
control the expression of Wingless in these boundary cells.
A preliminary model (Apterous-dependent network) was presented in 1, for the inter-cellular regulatory network activating Notch at the dorsal–ventral boundary in the wing imaginal disc of Drosophila. This model focussed on the cross-regulations between five genes (within and between two cells), which implements the dorsal–ventral border in the developing imaginal disc.
This refined model integrates both signaling processes into a multivalued model encompassing four cells, i.e., a boundary and a flanking cell at each side of the boundary. Computer simulations of this model enable a qualitative reproduction of the main wild-type and mutant phenotypes described in the experimental literature. During the first signaling process, Notch becomes activated by the first signaling process in an Apterous-dependent manner. In silico perturbation experiments show that this early activation of Notch is unstable in the absence of Apterous. However, during the second signaling process, the Notch pattern becomes consolidated, and thus independent of Apterous, through activation of the paracrine positive feedback circuit of Wingless. Consequently, we propose that appropriate delays for Apterous inactivation and Wingless induction by Notch are crucial to maintain the wild- type expression at the dorsal–ventral boundary. Finally, another mutant simulation shows that cut expression might be shifted to late larval stages because of a potential interference with the early signaling process.
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A. Gonzalez Gonzalez, A. Naldi, L. Sánchez, D. Thieffry, and C. Chaouiya. GINsim: a software suite for the qualitative modelling, simulation and analysis of regulatory networks. Biosystems, 84(2):91–100, May 2006. doi:10.1016/j.biosystems.2005.10.003. ↩