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Colonization of the Intestinal Surface by Indigenous Microbiota


Donaldson, Gregory Paul (2018) Colonization of the Intestinal Surface by Indigenous Microbiota. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/6EZ0-3007.


The mammalian gut evolved to foster the development and maintenance of a community of specific bacterial symbionts that persist for years. Bacteroides fragilis is one of a number of species that are able to colonize the mucus of the large intestine in mice and humans. This thesis explores the mechanisms and functions of mucosal colonization, most notably by using reductionist approaches with gnotobiotic mice. Harnessing genetics on both the host and microbial side allowed the dissection of a pathway by which immunoglobulin A enhances mucosal colonization by B. fragilis. Novel colonization assays were developed to explore the importance of mucosal colonization to bacterial fitness. Finally, an enrichment method for host-associated bacterial transcriptomics was used to define the behavior of this symbiont within the mucus layer.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Microbiota, Bacteroides, Colonization
Degree Grantor:California Institute of Technology
Division:Biology and Biological Engineering
Major Option:Microbiology
Awards:Milton and Francis Clauser Doctoral Prize, 2018. Lawrence L. and Audrey W. Ferguson Prize, 2018. Caltech Three Minute Thesis (3MT) competition, 2018: 2nd Place & People’s Choice.
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Mazmanian, Sarkis K.
Group:3MT Competition (Caltech)
Thesis Committee:
  • Newman, Dianne K. (chair)
  • Orphan, Victoria J.
  • Deshaies, Raymond Joseph
  • Mazmanian, Sarkis K.
Defense Date:26 April 2018
Funding AgencyGrant Number
NSF Graduate Research FellowshipDGE-1144469
NIH Training Grant5T32 GM07616
Heritage Medical Research InstituteUNSPECIFIED
Record Number:CaltechTHESIS:05082018-122340793
Persistent URL:
Related URLs:
URLURL TypeDescription adapted for Chapter 1. adapted for Chapter 2.
Donaldson, Gregory Paul0000-0002-8551-374X
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:10859
Deposited By: Gregory Donaldson
Deposited On:24 May 2018 23:09
Last Modified:16 May 2022 21:54

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