Journal Article

Co‐dynamics of Symbiodiniaceae and bacterial populations during the first year of symbiosis with Acropora tenuis juveniles

Alvarez Roa, Carlos, Quigley, Kate M., Willis, Bette L., Torda, Greg, Bourne, David G.

2020

Overview

Interactions between corals and their associated microbial communities (Symbiodiniaceae and prokaryotes) are key to understanding corals' potential for and rate of acclimatory and adaptive responses. However, the establishment of microalgal and bacterial communities is poorly understood during coral ontogeny in the wild. We examined the establishment and co‐occurrence between multiple microbial communities using 16S rRNA (bacterial) and ITS2 rDNA (Symbiodiniaceae) gene amplicon sequencing in juveniles of the common coral, Acropora tenuis, across the first year of development. Symbiodiniaceae communities in juveniles were dominated by Durusdinium trenchii and glynnii (D1 and D1a), with lower abundances of Cladocopium (C1, C1d, C50, and Cspc). Bacterial communities were more diverse and dominated by taxa within Proteobacteria, Cyanobacteria, and Planctomycetes. Both communities were characterized by significant changes in relative abundance and diversity of taxa throughout the year. D1, D1a, and C1 were significantly correlated with multiple bacterial taxa, including Alpha‐, Deltra‐, and Gammaproteobacteria, Planctomycetacia, Oxyphotobacteria, Phycisphaerae, and Rhizobiales. Specifically, D1a tended to associate with Oxyphotobacteria and D1 with Alphaproteobacteria, although these associations may represent correlational and not causal relationships. Bioenergetic modeling combined with physiological measurements of coral juveniles (surface area and Symbiodiniaceae cell densities) identified key periods of carbon limitation and nitrogen assimilation, potentially coinciding with shifts in microbial community composition. These results demonstrate that Symbiodiniaceae and bacterial communities are dynamic throughout the first year of ontology and may vary in tandem, with important fitness effects on host juveniles. We characterized the establishment and maintenance of bacterial and Symbiodiniaceae communities in the coral Acropora tenuis across the first year of juvenile ontogeny, identifying potentially key co‐occurrence patterns using network modeling. Bioenergetic modeling combined with physiological measurements of coral juveniles (surface area and Symbiodiniaceae cell densities) identified periods of carbon limitation and nitrogen assimilation, potentially coinciding with shifts in microbial community composition. These dynamic communities vary in tandem with important fitness effects on host juvenile corals.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc,Wiley
• Subject: 16S rRNA gene / Abundance / Acropora tenuis / Adaptation / Age Factors / Animals / Anthozoa - microbiology / Bacteria / Bacterial Physiological Phenomena / Community composition / Computational Biology - methods / coral / Coral reefs / Corals / coral‐associated bacteria / co‐occurrence / Cyanobacteria / DNA, Ribosomal Spacer / Ecosystems / Gene Ontology / Gene sequencing / ITS2 rDNA gene / juvenile / Juveniles / Metagenomics - methods / Microbial activity / Microbiota / Microorganisms / Molecular Typing / Ontogeny / Original / Prokaryotes / Relative abundance / RNA, Ribosomal, 16S - genetics / rRNA 16S / Sperm / Symbiodiniaceae / Symbiosis