MITACS Math Biology Seminar 2006

  • Date: 04/26/2006

Arpita Upadhyaya (University of Maryland)


University of British Columbia


A fundamental attribute of living cells is their ability to move. I
will talk about two forms of biological motion driven by different
physical mechanisms. The polymerization of the protein, actin, appears
to be the source of the propulsive force for eukaryotic cell motion.
While the alphabet soup of proteins that initiate and control actin
polymerization is being scrupulously characterized, it is not clear how
this generates a force to push. I will describe experiments in which we
have reconstructed motility using phospholipid vesicles as model cell
membranes in order to probe the polymerization forces. Vorticella, one
of the most powerful cellular machines, is a single celled organism
with a cell body attached to a substrate by a slender stalk which
contains a rod-like polymeric structure - the spasmoneme. Vorticella
motility is characterized by an extremely rapid contraction which is
powered by the collapse of the spasmoneme. We have conducted high-speed
imaging experiments to study the dynamics of contraction.