Coral reef ecosystems are in rapid decline due to global and local
anthropogenic factors. Being among the most diverse ecosystems on Earth, a loss will
decrease species diversity, and remove food source for people along the coast.
The coral together with its symbionts (i.e. Symbiodinium, bacteria, and other
microorganisms) is called the ‘coral holobiont’. The coral host offers its associated
symbionts suitable habitats and nutrients, while Symbiodinium and coral-associated
bacteria provide the host with photosynthates and vital nutrients. Association of corals
with certain types of Symbiodinium and bacteria confer coral stress tolerance, and lack
or loss of these symbionts coincides with diseased or bleached corals. However, a
detailed understanding of the coral holobiont diversity and structure in regard to
diseases and health states or across global scales is missing.
This dissertation addressed coral-associated symbiont diversity, specifically of
Symbiodinium and bacteria, in various coral species from different geographic
locations and different health states. The main aims were (1) to expand the scope of
existing technologies, (2) to establish a standardized framework to facilitate
comparison of symbiont assemblages over coral species and sites, (3) to assess
Symbiodinium diversity in the Arabian Seas, and (4) to elucidate whether coral health
states have conserved bacterial footprints.
In summary, a next generation sequencing pipeline for Symbiodinium diversity
typing of the ITS2 marker is developed and applied to describe Symbiodinium
diversity in corals around the Arabian Peninsula. The data show that corals in the
Arabian Seas are dominated by a single Symbiodinium type, but harbor a rich variety
of types in low abundant. Further, association with different Symbiodinium types is
structured according to geographic locations. In addition, the application of 16S rRNA gene microarrays to investigate how differences in microbiome structure relate
to differences in health and disease demonstrate that coral species share common
microbial footprints in phenotypically similar diseases that are conserved between
regional seas. Moreover, corals harbor bacteria that are species-specific and distinct
from the diseased microbial footprints. The existence of conserved coral disease
microbiomes allows for cataloging diseases based on bacterial assemblage over coral
species boundaries and will greatly facilitate future comparative analyses.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/336198 |
| Date | 12 1900 |
| Creators | Arif, Chatchanit |
| Contributors | Voolstra, Christian R., Biological and Environmental Sciences and Engineering (BESE) Division, Stingl, Ulrich, Ravasi, Timothy, Burt, John |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Rights | 2015-12-01, At the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation became available to the public after the expiration of the embargo on 2015-12-01. |
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