Intraspecific Differences in Molecular Stress Responses and Coral Pathobiome Contribute to Mortality Under Bacterial Challenge in Acropora millepora

Authors

Rachel M. Wright, The University of Texas at AustinFollow
Carly D. Kenkel, Australian Institute of Marine Science
Carly E. Dunn, The University of Texas at Austin
Erin N. Shilling, The University of Texas at Austin
Line K. Bay, Australian Institute of Marine Science
Mikhail V. Matz, The University of Texas at Austin

Document Type

Article

Publication Date

12-1-2017

Publication Title

Scientific Reports

Abstract

Disease causes significant coral mortality worldwide; however, factors responsible for intraspecific variation in disease resistance remain unclear. We exposed fragments of eight Acropora millepora colonies (genotypes) to putatively pathogenic bacteria (Vibrio spp.). Genotypes varied from zero to >90% mortality, with bacterial challenge increasing average mortality rates 4-6 fold and shifting the microbiome in favor of stress-associated taxa. Constitutive immunity and subsequent immune and transcriptomic responses to the challenge were more prominent in high-mortality individuals, whereas low-mortality corals remained largely unaffected and maintained expression signatures of a healthier condition (i.e., did not launch a large stress response). Our results suggest that lesions appeared due to changes in the coral pathobiome (multiple bacterial species associated with disease) and general health deterioration after the biotic disturbance, rather than the direct activity of any specific pathogen. If diseases in nature arise because of weaknesses in holobiont physiology, instead of the virulence of any single etiological agent, environmental stressors compromising coral condition might play a larger role in disease outbreaks than is currently thought. To facilitate the diagnosis of compromised individuals, we developed and independently cross-validated a biomarker assay to predict mortality based on genes whose expression in asymptomatic individuals coincides with mortality rates.

Volume

7

Issue

1

DOI

10.1038/s41598-017-02685-1

Comments

Archived as published. Open access article.

Recommended Citation

Wright, Rachel M.; Kenkel, Carly D.; Dunn, Carly E.; Shilling, Erin N.; Bay, Line K.; and Matz, Mikhail V., "Intraspecific Differences in Molecular Stress Responses and Coral Pathobiome Contribute to Mortality Under Bacterial Challenge in Acropora millepora" (2017). Biological Sciences: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/bio_facpubs/180