Genomics and cell biology of symbiois in Aiptasia, a model system for coral-algal symbiosis
Abstract/Contents
- Abstract
- The health and success of coral reef ecosystems is dependent upon the symbiotic relationship between coral animals and dinoflagellate algae (Symbiodinium spp.). Under thermal stress, corals can suffer from bleaching, a loss of Symbiodinium cells from the coral tissue that can be fatal during prolonged or severe stress. If stress is mild, corals can recover from bleaching through the repopulation of remaining Symbiodinium, or acquisition of new Symbiodinium from the environment. Despite the ecological importance of these processes, little is known about the molecular and cellular mechanisms underlying the establishment of coral-dinoflagellate symbiosis or its breakdown in bleaching. In this thesis, my collaborators and I use the small, symbiotic sea anemone Aiptasia as a model system for the study of cnidarian-dinoflagellate symbiosis. Using Aiptasia, we were able to test a popular hypothesis that the susceptibility of coral to bleaching is largely determined by the thermal tolerance of its algal symbiont and found that, indeed the type of algae hosted by an anemone had a strong effect on its susceptibility to bleaching, and that there was little effect of host genotype. Next, we examined the role of lectin-like proteins in the establishment of symbiosis and symbiosis specificity in Aiptasia. We identified several genes with homology to lectins that are differentially expressed between aposymbiotic and symbiotic Aiptasia. We recombinantly expressed one of these lectin-like proteins, Ctl1, and found that it bound preferentially to a type of algae that is incapable of establishing a symbiotic relationship with Aiptasia, suggesting a possible role in discriminating between different Symbiodinium types. Finally, to further the development of Aiptasia as a model system, we sequenced and assembled the Aiptasia genome. To search for genes and pathways that may be involved in symbiosis, we compared the genome of Aiptasia to the symbiotic coral Acropora digitifera, and to the anemone Nematostella, which does not have a symbiotic relationship with dinoflagellates. We identified a novel class of lectin-like genes that are enriched in the genome of the two symbiotic cnidarians, and may play a role in symbiosis establishment. The work presented here furthers our understanding of a symbiosis that is vital to the health of coral ecosystems and may provide tangible support to conservation efforts by identifying factors that contribute to susceptibility to bleaching and the ability to recover by acquiring novel symbionts.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Esherick, Lisl Y | |
|---|---|---|
| Associated with | Stanford University, Department of Genetics. | |
| Primary advisor | Pringle, John | |
| Thesis advisor | Pringle, John | |
| Thesis advisor | Bassik, Michael | |
| Thesis advisor | Fire, Andrew Zachary | |
| Thesis advisor | Schneider, David (David Samuel) | |
| Advisor | Bassik, Michael | |
| Advisor | Fire, Andrew Zachary | |
| Advisor | Schneider, David (David Samuel) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Lisl Ye Esherick. |
|---|---|
| Note | Submitted to the Department of Genetics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Lisl Y Esherick
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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