Dynamics of the Dorsal morphogen gradient.
The dorsoventral (DV) patterning of the Drosophila embryo depends on the nuclear localization gradient of Dorsal (Dl), a protein related to the mammalian NF-kappaB transcription factors. Current understanding of how the Dl gradient works has been derived from studies of its transcriptional interpretation, but the gradient itself has not been quantified. In particular, it is not known whether the Dl gradient is stable or dynamic during the DV patterning of the embryo. To address this question, we developed a mathematical model of the Dl gradient and constrained its parameters by experimental data. Based on our computational analysis, we predict that the Dl gradient is dynamic and, to a first approximation, can be described as a concentration profile with increasing amplitude and constant shape. These time-dependent properties of the Dl gradient are different from those of the Bicoid and MAPK phosphorylation gradients, which pattern the anterior and terminal regions of the embryo. Specifically, the gradient of the nuclear levels of Bicoid is stable, whereas the pattern of MAPK phosphorylation changes in both shape and amplitude. We attribute these striking differences in the dynamics of maternal morphogen gradients to the differences in the initial conditions and chemistries of the anterior, DV, and terminal systems.
Kanodia
Jitendra S
JS
Department of Chemical Engineering and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Washington Road, Princeton, NJ 08544, USA.
Rikhy
Richa
R
Kim
Yoosik
Y
Lund
Viktor K
VK
DeLotto
Robert
R
Lippincott-Schwartz
Jennifer
J
Shvartsman
Stanislav Y
SY
D000818:Animals; D019521:Body Patterning; D002467:Cell Nucleus / Q000378:metabolism; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D015534:Trans-Activators; D014157:Transcription Factors; C056478:bcd protein, Drosophila; C062236:dl protein, Drosophila; D020928:Mitogen-Activated Protein Kinases