Investigating Immunity Post Heat Stress in the Model Cnidarian, Exaiptasia diaphana




Womack, Haley

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Due to anthropogenic stressors, such as the rapid rate of climate change, coral reefs are in decline. Rising sea surface temperatures have been linked to mass bleaching events in which the symbiotic relationship of the coral and photosynthetic algae living within its tissue is broken down. Disease prevalence and severity has also increased following bleaching events, leading to interest in understanding how immunity and symbiosis or interconnected. In order to experimentally investigate this, we used the model anemone Exaiptasia diaphana. The close relatedness of these anemones to other cnidarians such as reef-building corals allows our results to be applicable to coral reef ecosystems without the difficulty of working with corals in the lab. In our experiment, we exposed anemones to a heat stress in the lab and sampled before, during and after the heat stress to understand how symbiont density and immunity changed both during heat stress and following recovery from heat stress. Our results show no significant difference between treatment groups over time in changes of symbiont densities or immune activity. However, we do see significant correlation between immune activity and experimental timepoint, suggesting that the time spent in the well plates used for the experiment had the strongest impact on immune profiles in this experiment. We also found a weak positive correlation between catalase activity and symbiont density which is likely in response to the symbionts producing excess reactive oxygen species during stressful conditions.



coral, immunity, honors


Womack, H. (2023). Investigating immunity post heat stress in the model cnidarian, Exaiptasia diaphana. Honors College, Texas State University.


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