Computational Modeling of the Shoot Apical Meristem

Start: 04/23/2008 - 11:00am
End  : 04/23/2008 - 12:00pm

Applied Math Seminar

Dr. Bruce Shapiro (Caltech, JPL & CSU Northridge)


The shoot apical meristem (SAM) is a dome-shaped collection of cells at the apex
of growing plants from which all above-ground tissue ultimately derives. In Arabidopsis
thaliana (thale cress), a small flowering weed of the Brassicaceae family (related
to mustard and cabbage), the SAM typically contains some three to five hundred
cells that range from five to ten microns in diameter. These cells are organized into
several distinct zones that maintain their topological and functional relationships
throughout the life of the plant. As the plant grows, organs (primordia) form on its
surface flanks in a phyllotactic pattern that develop into new shoots, leaves, and
flowers. The central region contains pluripotent stem cells that continue to divide
and differentiate into mature tissue throughout the life of the plant. In the computable
plant project we observe several cell type-specific markers for growth and differentiation
in live Arabidopsis plants with a dedicated confocal laser scanning microscope. These
markers are affixed to various gene products or promoter regions using green fluorescent
protein (GFP) variants that flouresce when they are illuminated within the microscope by
a laser. This allows us to observe various meristem and floral primordial features, such
as membranes and nuclei, and to track specific cell lineages over time. By using
mathematical and computational models of these spatiotemporal expression patterns,
we can infer how primordial cells are progressively specified and organs develop.
The talk will survey the modeling techniques and tools used and the modeling results
produced in this project.

CGU Math South (710 N. College Ave)