Constructing a motile cell : how extrinsic information and intrinsic self-organization coordinate the mechanics of cellular behavior
Abstract/Contents
- Abstract
- The actin-based crawling motility of eukaryotic cells is a vital example of emergent cellular behavior arising from the mechanical output of thousands to millions of individual chemical reactions occurring every second. In this work, I describe a set of experimental and analytical results that seek to reveal the underlying organization and operations of this micron sized biological machine. We found that the morphology of crawling cells is quantitatively dictated by the cytoskeletal elements that produce motility. Each cell is unique in its organization and behavior, and across a population of cells this variation could largely be reduced to a single dimension. Globally perturbing the biochemical reaction rates that drive motility with changes in temperature forced individual cells out of their steady state behavior along this same single dimension of variation. In addition individual cells fluctuated harmonically around their steady state behavior, suggesting a mechanical oscillator arising from the coupling of the processes of actin meshwork assembly and disassembly. Flickers of elevated intracellular concentration of the canonical secondary messenger calcium were seen, but these calcium flickers were not required for cell motion nor were they correlated with any measured change in cell behavior. The orientation of motion, similar to the rate of motion, is directly coupled to the cytoskeletal organization and cellular shape. To change their direction of migration, cells develop asymmetries in the interwoven actions of myosin contractility and adhesion to the substrate at the rear of the cell creating asymmetric centripetal actin flow. This system of controlling orientation was responsive to external cues from electric fields secondary to electrophoretic redistribution of charged membrane components extending into the extracellular space.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2013 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Allen, Greg Maness |
|---|---|
| Associated with | Stanford University, Department of Biochemistry. |
| Primary advisor | Theriot, Julie |
| Thesis advisor | Theriot, Julie |
| Thesis advisor | Chu, Gilbert |
| Thesis advisor | Straight, Aaron, 1966- |
| Advisor | Chu, Gilbert |
| Advisor | Straight, Aaron, 1966- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Greg Maness Allen. |
|---|---|
| Note | Submitted to the Department of Biochemistry. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2013. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2013 by Greg Maness Allen
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...