Long-term heat selection of the coral endosymbiont Cladocopium C1acro (Symbiodiniaceae) stabilizes associated bacterial communities

Patrick Buerger*, Ruby T. Vanstone, Justin Maire, Madeleine J. H. van Oppen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)
12 Downloads (Pure)


Heat-tolerant strains of the coral endosymbiont, Cladocopium C1acro (Symbiodiniaceae), have previously been developed via experimental evolution. Here, we examine physiological responses and bacterial community composition (using 16S rRNA gene metabarcoding) in cultures of 10 heat-evolved (SS) and 9 wild-type (WT) strains, which had been exposed for 6 years to 31 °C and 27 °C, respectively. We also examine whether the associated bacterial communities were affected by a three-week reciprocal transplantation to both temperatures. The SS strains had bacterial communities with lower diversities that showed more stability and lower variability when exposed to elevated temperatures compared with the WT strains. Amplicon sequence variants (ASVs) of the bacterial genera Labrenzia, Algiphilus, Hyphobacterium and Roseitalea were significantly more associated with the SS strains compared with the WT strains. WT strains showed higher abundance of ASVs assigned to the genera Fabibacter and Tropicimonas. We hypothesize that these compositional differences in associated bacterial communities between SS and WT strains also contribute to the thermal tolerance of the microalgae. Future research should explore functional potential between bacterial communities using metagenomics to unravel specific genomic adaptations.
Original languageEnglish
Article number4913
Pages (from-to)1-18
Number of pages18
JournalInternational Journal of Molecular Sciences
Issue number9
Early online date28 Apr 2022
Publication statusPublished - 1 May 2022

Bibliographical note

Copyright the Author(s) 2022. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


  • Symbiodiniaceae
  • coral
  • microbiome
  • 16S rRNA metabarcoding
  • experimental evolution
  • thermal tolerance


Dive into the research topics of 'Long-term heat selection of the coral endosymbiont Cladocopium C1acro (Symbiodiniaceae) stabilizes associated bacterial communities'. Together they form a unique fingerprint.

Cite this