Investigating impacts of heat stress on symbiosis in cnidarian larvae using high-throughput fluorescence-based quantification
Abstract/Contents
- Abstract
- Reef-building corals (phylum Cnidaria) exist in symbiotic relationships with photosynthetic dinoflagellate algae in the family Symbiodiniaceae. Under heat stress, corals lose these algal symbionts, resulting in a phenomenon known as coral bleaching. Due to rising seawater temperatures, more frequent bleaching events have led to significant degradation of coral-reef ecosystems worldwide. Much recent research has focused on whether the preferential association of adult coral polyps with thermotolerant species of algae improves resilience to bleaching. However, similar work on coral larvae has been limited. This study investigated the impacts of heat stress on the uptake and ejection of algae by cnidarians at the earliest stage of their life cycle, free-swimming larvae. Using the sea anemone Aiptasia as a model system, we addressed two questions – (1) the impact of heat stress on algal ejection by larvae populated with three different strains of algae of known thermal tolerances: SSA01, SSB01, and Mf2.2b (bleaching experiments) and (2) the impact of heat stress on symbiosis establishment in Aiptasia larvae with these three strains of algae (acquisition experiments). Uptake and ejection of algae by larvae were quantified using a novel high-throughput fluorescence-based sorting protocol employing the Union Biometrica BioSorter. Under control conditions in the bleaching experiments, Aiptasia larvae infected with SSA01 had the highest algal density, and in the acquisition experiments, larvae infected with SSB01 reached the highest algal density. The latter preference mimicked that of adults. Under heat stress, larval acquisition of algae was reduced across all three strains of algae; however, larvae that acquired SSA01 had higher algal densities than larvae exposed to the other two strains. Similarly, larvae already infected with SSA01 retained higher algal densities and even displayed proliferation of algae upon exposure to heat stress, compared to larvae infected with SSB01 or Mf2.2b. These results are surprising as Mf2.2b has been characterized before to be the most thermally tolerant algal strain in culture and in corals, followed by SSA01 and SSB01. One possible explanation might be that, unlike Mf2.2b, SSA01 and SSB01 are the native symbionts found in the male and female parent strains, respectively, with SSA01 being the more thermally tolerant of these two strains. This study is the first to investigate algal preferences in cnidarian larvae under heat stress at a high-throughput scale, and it provides new insights into the relatively understudied early life stage of cnidarians.
Description
| Type of resource | text |
|---|---|
| Publication date | May 4, 2023 |
Creators/Contributors
| Author | Paul, Maitri |
|---|---|
| Thesis advisor | Renicke, Christian |
| Thesis advisor | Long, Sharon |
| Research team head | Pringle, John |
| Degree granting institution | Stanford University, Department of Biology |
Subjects
| Subject | Coral bleaching, cnidarian-algal symbiosis, heat stress, cnidarian larvae |
|---|---|
| Genre | Text |
| Genre | Thesis |
Bibliographic information
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- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International license (CC BY-NC).
Preferred citation
- Preferred citation
- Paul, M., Renicke, C., and Pringle, J. (2023). Investigating impacts of heat stress on symbiosis in cnidarian larvae using high-throughput fluorescence-based quantification. Stanford Digital Repository. Available at https://purl.stanford.edu/hs099cc5511. https://doi.org/10.25740/hs099cc5511.
Collection
Undergraduate Theses, Department of Biology, 2022-2023
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