- Restrictions on Access:
- Open Access.
- Bacteria colonize and form symbiotic relationships with a broad range of plant and animal hosts, where they significantly impact host health and development. To establish symbioses, bacteria in the external environment must adopt specific physiological states which are conducive to colonization and survival within their host environment. Many bacterial species can regulate their physiology through quorum sensing, which is a contact-independent signaling mechanism based on small, diffusible autoinducers that induce behaviors within bacteria. Much of our current knowledge about quorum sensing is based on studies in culture, where autoinducers are contained within the immediate area. However, in the host, there are fewer barriers to the diffusion of small molecules so autoinducers can diffuse away from the populations that synthesize them. This work aims to close this gap in knowledge by evaluating how the diffusion of autoinducers within the host environment affects quorum sensing-mediated regulation of symbiont physiology. Vibrio fischeri is a bacterium that uses quorum sensing to regulate bioluminescence production in its symbiosis with the Hawaiian bobtail squid Euprymna scolopes. V. fischeri colonizes specific spatially segregated sites within the squid. The main goal of this work is to evaluate the detection of and response to autoinducers generated by distant V. fischeri populations in the squid. A natural isolate of V. fischeri was characterized for its ability to utilize quorum sensing to regulate bioluminescence in the host. This work evaluates how the induction of bioluminescence by autoinducer-producing populations promotes the survival of distant symbionts in the squid over time. We demonstrate that autoinducers diffuse throughout the light organ, which promotes the detection and induction of bioluminescence within spatially segregated populations of V. fischeri, thereby promoting the survival of these symbionts within the squid over time.
- Dissertation Note:
- B.S. Pennsylvania State University 2020.
- Technical Details:
- The full text of the dissertation is available as an Adobe Acrobat .pdf file ; Adobe Acrobat Reader required to view the file.
View MARC record | catkey: 30585579