*************** ANNOUNCEMENT **********************
* University of Utah Mathematical Biology Seminar *
***************************************************

NOTE UNUSUAL DAY and TIME:

Tuesday, April 27 at 3 pm in INSCC 110
========

Speaker:  Paul Kulesa

Title:  Neural Crest Cell Dynamics Revealed by Time-Lapse Video Microscopy of
Whole Embryo Chick Explant Cultures


Abstract: 

How information is organized along an axis in the developing
vertebrate embryo is a major question in developmental biology.  One
example is the formation of the vertebrate nervous system, where the
hindbrain portion of the neural tube is shaped into segments which are
thought to provide a spatial groundplan for cell differentiation and a
migratory population of cells, called cranial neural crest, which give
rise to much of the peripheral nervous system.  Because neural crest
cells undergo extensive migrations and give rise to many diverse
derivatives, they are an important model system for the study of cell
movements, cell proliferation and differentiation.  However, the lack
of visualizing the precise trajectories of cells in living vertebrate
embryos has made it difficult to determine the factors influencing the
migratory pathways of individual cells.

We take advantage of the chick embryo to perform direct observations
of the migration characteristics of neural crest cells in living whole
chick embryo explants using time-lapse confocal imaging.  Time-lapse
movies of fluorescently-labelled cells show a wide variety of neural
crest cell migration behaviors ranging from migration as individuals
to more collective movements as groups.  Some of these behaviors
demonstrate obvious opportunities for cell-cell communication during
migration.  The unpredictable cell trajectories, the mixing of neural
crest cells between adjacent segments of the hindbrain and the
diversity in cell migration behavior within any particular region
imply that no single mechanism guides migration.  Regional differences
in cell migration characteristics suggest that influential factors may
vary spatially along the rostrocaudal axis in the head.