Investigating the mechanisms for phototaxis in the cyanobacterium Synechocystis sp. PCC 6803
Abstract/Contents
- Abstract
- Signal transduction in bacteria is complex, ranging across scales from molecular sig- nal detectors and effectors to cellular and community responses to a stimulus. The unicellular, photosynthetic cyanobacterium Synechocystis sp. PCC6803 transduces a light stimulus into directional movement known as phototaxis. This single-cell response occurs via a biased random walk toward or away from a directional light source, which is sensed by intracellular photoreceptors and mediated by Type IV pili. In this dissertation, I will discuss how I have used the combined manipulations of the light conditions, genetic perturbations, quantitative, single-cell measurements, and a reaction diffusion model to derive simple guiding principles across length scales for cell motility. I first demonstrate that cells indirectly interact with each other via a secreted substance that enhances their mobility, These intercellular interactions re- sult in the dynamic spatial organization of the multicellular community, which do not appear to require changes in individual behavior. I then show how movement directionality of the single cell is determined mainly by the light signal, and is the result of a polarization of pilus pulling forces along the light axis. Finally, I will reveal the newly identified role of the photoreceptor TaxD1 in enhancing movement direction- ality, in addition to its previously shown role in promoting positive phototaxis. Our broadly applicable framework can also be used to dissect similar complex regulatory networks that effects robust responses from input signals.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2015 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Chau, Man Wah Rosanna |
|---|---|
| Associated with | Stanford University, Department of Bioengineering. |
| Primary advisor | Bhaya, Devaki, 1957- |
| Primary advisor | Huang, Kerwyn Casey, 1979- |
| Thesis advisor | Bhaya, Devaki, 1957- |
| Thesis advisor | Huang, Kerwyn Casey, 1979- |
| Thesis advisor | Riedel-Kruse, Hans |
| Thesis advisor | Sonnenburg, Justin, 1973- |
| Advisor | Riedel-Kruse, Hans |
| Advisor | Sonnenburg, Justin, 1973- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Rosanna Man Wah Chau. |
|---|---|
| Note | Submitted to the Department of Bioengineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2015. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2015 by Man Wah Rosanna Chau
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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