Scientific

Models for Cell Shape and Actin Filament Distributions

Speaker: 
Leah Edelstein-Keshet
Date: 
Tue, May 22, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 

In this lecture I describe a model by Grimm et al (2003) Eur Biophys J 32: 563-577. The authors ask what processes might account for a parabolic density profile of actin seen across the front edge of a keratocyte. In an elegant coupled PDE model, they show that right and left growing actin filaments, competing for the actin branching complex Arp2/3 have solutions with the appropriate profile. I here
consider one of the cases, that of local competition and slow capping of filaments, where the equations are fully analytically solvable in closed form.

Class: 

Mathematical Cell Biology Summer Course Lecture 31

Speaker: 
Dimitrios Vavylonis
Date: 
Tue, May 22, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 
  • Diffusion-controlled processes in the cell and sensing in bacterial chemotaxis
    • Compact vs non-Compact Exploration [deGennes, Macromolecules 1982]
    • Bacterial Chemotaxis [Berg and Purcell Biophys J 1977]
    • Reduction of Dimensionality [Philips, Kondev and Theriot, Physical Biology of the Cell]
    • Formins and Tip-tracking
Class: 

Mathematical Cell Biology Summer Course Lecture 30

Speaker: 
Hildor
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 

TBA

Class: 

Mathematical Cell Biology Summer Course Lecture 29

Speaker: 
William Holmes
Date: 
Fri, May 18, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 
  • Local Pulse Analysis for RD equations
  • Actin Waves
  • Matlab examples and exercises
Class: 

Mathematical Cell Biology Summer Course Lecture 28

Speaker: 
Raibatak (Dodo) Das
Date: 
Fri, May 18, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 

Data Analysis Methods

Class: 

Self Organization in Cells - How to Use Proteins to Solve a Geometry Problem

Speaker: 
Eric Cytrynbaum
Date: 
Thu, May 17, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 

Fragments of fish pigment cells can form and center aggregates of
pigment granules by dynein-motor-driven transport along a
self-organized radial array of microtubules (MTs). I will present a
quantitative model that describes pigment aggregation and MT-aster
self-organization and the subsequent centering of both structures.
The model is based on the observations that MTs are immobile and
treadmill, while dynein-motor-covered granules have the ability to
nucleate MTs. From assumptions based on experimental observations,
I'll derive partial integro-differential equations describing the
coupled granule-MT interaction. Analysis explains the mechanism of
aster self-organization as a positive feedback loop between motor
aggregation at the MT minus ends and MT nucleation by motors.
Furthermore, the centering mechanism is explained as a global
geometric bias in the cell established by spontaneously-nucleated
microtubules. Numerical simulations lend additional support to the
analysis. The model sheds light on role of polymer dynamics and
polymer-motor interactions in cytoskeletal organization.

Class: 

Spatial Segregation of Polarity Determinants in Embryos of the Nematode Worm C. elegans

Speaker: 
Adriana Dawes
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 

Polarization, where cells segregate specific factors to distinct domains, is a fundamental and evolutionarily conserved biological process. Polarizing cells often rely on the same toolkit of proteins and lipids, including actin, myosin, microtubules and the Par and Rho protein families. In this talk, I will present experimental and theoretical work demonstrating the importance of Par protein oligomerization for stable spatial segregation in early embryos of C. elegans. I will discuss some current research directions in my lab, including the incorporation of Rho proteins into our theoretical and experimental frameworks.

Class: 

Mathematical Cell Biology Summer Course Lecture 27

Speaker: 
William Holmes
Date: 
Thu, May 17, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 
  • Local Pulse Analysis for RD equations
  • Actin Waves
  • Matlab examples and exercises
Class: 

Mathematical Cell Biology Summer Course Lecture 26

Speaker: 
William Holmes
Date: 
Wed, May 16, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 
  • Local Pulse Analysis for RD equations
  • Actin Waves
  • Matlab examples and exercises
Class: 

Diffusion, Reaction, and Biological pattern formation (continued 3 of 3)

Speaker: 
Leah Edelstein-Keshet
Date: 
Wed, May 16, 2012
Location: 
PIMS, University of British Columbia
Conference: 
Mathematical Cell Biology Summer Course
Abstract: 

Here I return the pattern-formation discussion to the context of symmetry breaking and chemical patterns of GTPases such as Cdc42, Rac and Rho in cell polarization. I explain the spatial context of GTPase distributions in a stimulated chemotactic cell and derive the system of partial differential equations (PDEs) for these. These examples motivate the usefulness of LPA as an additional tool in testing for pattern formation and polarizability.

Class: 

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