The role of feedback in the formation of morphogen territories.
In this paper, we consider a mathematical model for the formation of spatial morphogen territories of two key morphogens: Wingless (Wg) and Decapentaplegic (DPP), involved in leg development of Drosophila. We define a gene regulatory network (GRN) that utilizes autoactivation and cros-sinhibition (modeled by Hill equations) to establish and maintain stable boundaries of gene expression. By computational analysis we find that in the presence of a general activator, neither autoactivation, nor cross-inhibition alone are sufficient to maintain stable sharp boundaries of morphogen production in the leg disc. The minimal requirements for a self-organizing system are a coupled system of two morphogens in which the autoactivation and cross-inhibition have Hill coefficients strictly greater than one. In addition, the GRN modeled here describes the regenerative responses to genetic manipulations of positional identity in the leg disc.
Iron
David
D
Dalhousie University, Department of Mathematics and Statistics. iron@mathstat.dal.ca
Syed
Adeela
A
Theisen
Heidi
H
Lukacsovich
Tamas
T
Naghibi
Mehrangiz
M
Marsh
Lawrence J
LJ
Wan
Frederic Y M
FY
Nie
Qing
Q
D000465:Algorithms; D000818:Animals; D004058:Diffusion; D004330:Drosophila / Q000196:embryology* / Q000235:genetics; D029721:Drosophila Proteins / Q000378:metabolism; D005121:Extremities / Q000196:embryology; D025461:Feedback, Physiological; D005786:Gene Expression Regulation; D008954:Models, Biological; D015233:Models, Statistical; D008962:Models, Theoretical; D015398:Signal Transduction; D012984:Software; D051155:Wnt1 Protein / Q000378:metabolism
D029721:Drosophila Proteins; D051155:Wnt1 Protein; C064196:dpp protein, Drosophila; C074622:wg protein, Drosophila