Photosymbiont Density Is Correlated with Constitutive and Induced Immunity in the Facultatively Symbiotic Coral, Astrangia poculata

Authors

Isabella V. Changsut, College of Science and Engineering
Erin M. Borbee, College of Science and Engineering
Haley R. Womack, College of Science and Engineering
Alicia Shickle, Roger Williams University
Koty H. Sharp, Roger Williams UniversityFollow
Lauren E. Fuess, College of Science and Engineering

Document Type

Conference Proceeding

Publication Title

Integrative and Comparative Biology

Publication Date

11-1-2024

Abstract

Scleractinian corals, essential ecosystem engineers that form the base of coral reef ecosystems, have faced unprecedented mortality in recent decades due to climate change-related stressors, including disease outbreaks. Despite this emergent threat to corals, many questions still remain regarding mechanisms underlying observed variation in disease susceptibility. Recent data suggest at least some degree of variation in disease response may be linked to variability in the relationship between host corals and their algal photosymbionts (Family Symbiodiniaceae). Still, the nuances of connections between symbiosis and immunity in cnidarians, including scleractinian corals, remain poorly understood. Here, we leveraged an emergent model species, the facultatively symbiotic, temperate, scleractinian coral Astrangia poculata, to investigate associations between symbiont density and both constitutive and induced immunity. We used a combination of controlled immune challenges with heat-inactivated pathogens and transcriptomic analyses. Our results demonstrate that A. poculata mounts a robust initial response to pathogenic stimuli that is highly similar to responses documented in tropical corals. We document positive associations between symbiont density and both constitutive and induced immune responses, in agreement with recent preliminary studies in A. poculata. A suite of immune genes, including those coding for antioxidant peroxiredoxin biosynthesis, are positively associated with symbiont density in A. poculata under constitutive conditions. Furthermore, variation in symbiont density is associated with distinct patterns of immune response; low symbiont density corals induce preventative immune mechanisms, whereas high symbiont density corals mobilize energetic resources to fuel humoral immune responses. In summary, our study reveals the need for more nuanced study of symbiosis-immune interplay across diverse scleractinian corals, preferably including quantitative energy budget analysis for full disentanglement of these complex associations and their effects on host pathogen susceptibility.

Volume

64

Issue

5

First Page

1278

Last Page

1290

DOI

10.1093/icb/icae036

Recommended Citation

Changsut, I., Borbee, E., Womack, H., Shickle, A., Sharp, K. H., & Fuess, L. (2024). Photosymbiont Density Is Correlated with Constitutive and Induced Immunity in the Facultatively Symbiotic Coral, Astrangia poculata. Integrative and Comparative Biology, 64 (5), 1278-1290. https://doi.org/10.1093/icb/icae036

ISSN

15407063

E-ISSN

15577023