Qing Nie
(Department of Mathematics,
Center for Biomedical Engineering, University of California, Irvine)
Tissue Patterning During Development
Abstract
Many patterns of cell and tissue organization are specified during development
by gradients of morphogens, substances that assign different cell fates at
different concentrations. Gradients form by morphogen transport from a localized
site, but whether this occurs by simple diffusion or by more elaborate mechanisms
is unclear. We attempt to resolve this controversy by analysis and computations
of ligand-receptor models of the system. In addition we examine recent experimental
data in ways that appropriately capture the complexity of the systems in
which transport, receptor interaction, endo- and exocytosis, and degradation
occur together. We find that diffusive mechanisms of morphogen transport
are much more plausible- and nondiffusive mechanisms much less plausible-than
has generally been argued. At the end of the talk, I will discuss the applications
of the ligand-receptor model to other tissue patterning problems.
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