The intestinal tract microbiota – microbial community of the gut – is an
important field in microbiology not only because of its critical role in the host
development, but also increasingly large number of diseases are associated
with certain state of the gut microbiota. The community structure and function
of the gut microbiota is relatively well studied in humans and related higher
vertebrates, but is severely understudied in fish. This is especially true for the
coral reef fishes, who constitute the most diverse assemblage of vertebrates
spread over a very local scale, and are essential for the resilience of the reefs.
In order to bridge this gap in knowledge, this dissertation studied the
community structure, interactions and functions of the gut microbial
community from the surgeonfishes in the Red Sea – with special focus on the
surgeonfish enteric symbiont Epulopiscium spp. Initially, I studied the
composition of the gut microbiota of nine surgeonfish and three
nonsurgeonfish species from the Red Sea using 454 pyrosequencing. Upon
discovering the high abundance of Epulopiscium spp. in herbivorous
surgeonfishes, I then proceeded to identify their phylogenetic diversity,
distribution, as well as deducing their coevolutionary relationship with the
host. Because Epulopiscium spp. undergo substantial changes in the cell size
(grow up to ~600μm) and the DNA concentration (from 85 to over 250pg per
cell) throughout their diel lifecycle, I also studied the temporal changes in their
expression pattern using RNA-seq. Overall, this dissertation shed light on the
complex structure, interaction and function of an important family of coral reef
fish from the Red Sea through range of molecular techniques.
Date of Award | May 2015 |
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Original language | English (US) |
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Awarding Institution | - Biological, Environmental Sciences and Engineering
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Supervisor | Ulrich Stingl (Supervisor) |
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- Gut Microbiota
- Epulopiscium
- community composition
- Differential Expression
- Coevolution
- Diel Lifecycle