J. A. Glazier
Department of Physics, University of Notre
Dame,
316 Nieuwland, Notre Dame, In 46556-5670
USA
During embryonic development, cells need
to migrate long distances through tissues.
How do they know where to go? Two basic mechanisms
are at work. Over long distances, cells secrete
and follow gradients of diffusible chemicals
(chemotaxis). Once they are approximately
in the correct position, variable adhesion
molecules expressed on their surfaces help
them to form coherent structures by energy
minimization (differential adhesion). Simulations
and quantitative experiments help disentangle
these processes. However, simulations require
assumptions about the behavior of individual
cells. The simplest assumption is that cells
behave like thermally excited particles but
a cell's cytoskeletal motors are not restricted
to quasi-thermal behavior. Recently we have
investigated how correlations in cell velocity
can lead to superdiffusion of sorting cells
and hence to faster sorting.