Speaker
Prof.
Anatoly Kolomeisky
(Department of Chemistry, Rice University)
Description
Concentration profiles of signaling molecules, also known as
morphogen gradients, play a critical role in the development
of multicellular organisms by determining polarity and
spatial patterning that leads to further tissue
differentiation. Large advances in studying morphogen
gradients have been achieved recently when the formation of
signaling molecules profiles has been visualized with high
temporal and spatial resolution. A widely used approach to
explain the establishment of concentration gradients assumes
that signaling molecules are produced locally, then spread
via a free diffusion and degraded uniformly. However, recent
experiments have produced controversial observations
concerning the feasibility of this theoretical description.
In addition, latest theoretical analysis of times to
establish the morphogen gradient yield surprising linear
scaling as a function of length, not expected for the
systems with unbiased diffusion process. We propose here a
theoretical approach that provides a possible microscopic
explanation of these observations. It is argued that
relaxation times are mostly determined by first-passage
times and the degradation effectively accelerates diffusion
of signaling particles by removing slow moving molecules.
Our theoretical analysis indicates that spatial and temporal
features of degradation mechanisms mostly control the
establishment of signaling molecules profiles.
Primary author
Prof.
Anatoly Kolomeisky
(Department of Chemistry, Rice University)
