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Article
Unfolding the secrets of coral - algal symbosis
The ISME Journal
  • Nedeljka Rosic, The University of Queensland, Australia
  • Edmund Yew Siang Ling, The University of Queensland, Australia
  • Chon-Kit Kenneth Chan, The University of Queensland, Australia
  • Hong Ching Lee, Garvan Institute of Medical Research, Sydney
  • Paulina Kaniewska, The University of Queensland, Australia
  • David Edwards, The University of Queensland, Australia
  • Sophie Dove, The University of Queensland, Australia
  • Ove Hoegh-Guldberg, The University of Queensland, Australia
Document Type
Article
Publication Date
1-1-2015
Peer Reviewed
Peer-Reviewed
Abstract
Dinoflagellates from the genus Symbiodinium form a mutualistic symbiotic relationship with reef-building corals. Here we applied massively parallel Illumina sequencing to assess genetic similarity and diversity among four phylogenetically diverse dinoflagellate clades (A, B, C and D) that are commonly associated with corals. We obtained more than 30 000 predicted genes for each Symbiodinium clade, with a majority of the aligned transcripts corresponding to sequence data sets of symbiotic dinoflagellates and <2% of sequences having bacterial or other foreign origin. We report 1053 genes, orthologous among four Symbiodiniumclades, that share a high level of sequence identity to known proteins from the SwissProt (SP) database. Approximately 80% of the transcripts aligning to the 1053 SP genes were unique to Symbiodinium species and did not align to other dinoflagellates and unrelated eukaryotic transcriptomes/genomes. Six pathways were common to all four Symbiodinium clades including the phosphatidylinositol signaling system and inositol phosphate metabolism pathways. The list of Symbiodiniumtranscripts common to all four clades included conserved genes such as heat shock proteins (Hsp70 and Hsp90), calmodulin, actin and tubulin, several ribosomal, photosynthetic and cytochrome genes and chloroplast-based heme-containing cytochrome P450, involved in the biosynthesis of xanthophylls. Antioxidant genes, which are important in stress responses, were also preserved, as were a number of calcium-dependent and calcium/calmodulin-dependent protein kinases that may play a role in the establishment of symbiosis. Our findings disclose new knowledge about the genetic uniqueness of symbiotic dinoflagellates and provide a list of homologous genes important for the foundation of coral–algal symbiosis.
Citation Information

Rosic, N, Ling, EYS, Chan, CKK, Lee, HC, Kaniewska, P, Edwards, D, Dove, S & Hoegh-Guldberg, O 2015, 'Unfolding the secrets of coral - algal symbosis', The ISME Journal, vol. 9, pp. 844-856.

Published version available from:

http://dx.doi.org/10.1038/ismej.2014.182