Leah Edelstein-Keshet

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  Navigating Biochemical Pathways for Cell Polarization and Motility (A Personal Journey)
  Leah Edelstein-Keshet

  Many cell types, including cells of the immune system, are able to polarize and crawl in response to chemical or mechanical stimuli. In this way, they can perform vital functions such as immune surveillance, wound healing, and tissue development. I will describe our efforts to understand the underlying biochemistry governing the initial direction sensing, polarization, cell shape change, and motility. While much of the biology is undergoing rapid discovery, we have found that mathematical ideas supply additional tools. Such tools help to decipher underlying mechanism, to weed between competing hypotheses, and to suggest new experimental tests. On the same journey, we also encountered some new and interesting mathematics.

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  Modeling flocks and swarms
  Leah Edelstein-Keshet
  I will summarize some work on the link between individual behaviour and the dynamics of the swarm/flock. I will highlight two projects:
  
  1. The behaviour of a 2D flock of aquatic birds, and how Ryan Lukeman (former PhD student, now at St FX University) figured out the underlying individual rules
  2. models for social foraging, an ongoing project in my group joint with Nessy Tania, Ben Vanderlei and Joel Heath.
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  Modeling the regulation of cell motility in normal and cancer cells
  Leah Edelstein-Keshet

  Cell motility is coordinated by an intricate network of interacting proteins and lipids, that transduce signals into cytoskeletal reorganization, cell shape changes, and locomotion. Here I will survey some mathematical modeling that addresses both normal and aberrant cell motility. I will describe efforts in my group to construct and analyse mathematical models for proteins (such as Rho family GTPases) and lipids (such as phosphoinositides), their feedbacks and their effects on protrusion and contraction of the cell front and rear, as well as cell shape. The role of the cytoskeleton and its actin-associated proteins (e.g. cofilin) will be mentioned. I will describe how several projects on cell polarity and GTPase spatial patterns have contributed to some insights into cell motility.