Marine Biotechnology

, Volume 12, Issue 5, pp 594–604

Patterns of Gene Expression in a Scleractinian Coral Undergoing Natural Bleaching

  • Francois O. Seneca
  • Sylvain Forêt
  • Eldon E. Ball
  • Carolyn Smith-Keune
  • David J. Miller
  • Madeleine J. H. van Oppen
Original Article

DOI: 10.1007/s10126-009-9247-5

Cite this article as:
Seneca, F.O., Forêt, S., Ball, E.E. et al. Mar Biotechnol (2010) 12: 594. doi:10.1007/s10126-009-9247-5

Abstract

Coral bleaching is a major threat to coral reefs worldwide and is predicted to intensify with increasing global temperature. This study represents the first investigation of gene expression in an Indo-Pacific coral species undergoing natural bleaching which involved the loss of algal symbionts. Quantitative real-time polymerase chain reaction experiments were conducted to select and evaluate coral internal control genes (ICGs), and to investigate selected coral genes of interest (GOIs) for changes in gene expression in nine colonies of the scleractinian coral Acropora millepora undergoing bleaching at Magnetic Island, Great Barrier Reef, Australia. Among the six ICGs tested, glyceraldehyde 3-phosphate dehydrogenase and the ribosomal protein genes S7 and L9 exhibited the most constant expression levels between samples from healthy-looking colonies and samples from the same colonies when severely bleached a year later. These ICGs were therefore utilised for normalisation of expression data for seven selected GOIs. Of the seven GOIs, homologues of catalase, C-type lectin and chromoprotein genes were significantly up-regulated as a result of bleaching by factors of 1.81, 1.46 and 1.61 (linear mixed models analysis of variance, P < 0.05), respectively. We present these genes as potential coral bleaching response genes. In contrast, three genes, including one putative ICG, showed highly variable levels of expression between coral colonies. Potential variation in microhabitat, gene function unrelated to the stress response and individualised stress responses may influence such differences between colonies and need to be better understood when designing and interpreting future studies of gene expression in natural coral populations.

Keywords

Coral bleachingMolecular stress responseGene expressionQuantitative PCRInternal control geneInter-colony variability

Supplementary material

10126_2009_9247_Fig4_ESM.jpg (428 kb)
Table S1

Primers used for the genes under investigation in the qPCR experiment. The best Tblastx match and E value are shown for the EST sequence corresponding to the indicated accession number. The Symbiodinium-specific PCNA primers were designed on the same sequences used in Boldt et al. (2009) (JPEG 428 kb)

10126_2009_9247_Fig1_ESM.eps (602 kb)
Table S1High resolution image (EPS 601 kb)
10126_2009_9247_Fig5_ESM.jpg (98 kb)
Table S2

Ranking of the candidate ICGs according to their M and CV values (Hellemans et al. 2007) calculated between healthy-looking and severely bleached samples across the nine colonies used in qPCR experiment (JPEG 97 kb)

10126_2009_9247_Fig2_ESM.eps (313 kb)
Table S2High resolution image (EPS 313 kb)
10126_2009_9247_MOESM3_ESM.pdf (1.6 mb)
Table S3The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) checklist for reviewers and editors (Bustin et al. 2009) (PDF 1669 kb)
10126_2009_9247_Fig6_ESM.jpg (505 kb)
Figure S1

Consistent difference between average quantification cycles of healthy (dark grey) and bleached (light grey) samples in nine colonies, for the best performing ICGs: GAPDH, rpL9 and S7 (JPEG 505 kb)

10126_2009_9247_Fig4_ESM.eps (418 kb)
Figure S1High resolution image (EPS 418 kb)

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Francois O. Seneca
    • 1
    • 2
    • 3
  • Sylvain Forêt
    • 5
  • Eldon E. Ball
    • 4
  • Carolyn Smith-Keune
    • 3
    • 6
    • 7
  • David J. Miller
    • 1
    • 2
  • Madeleine J. H. van Oppen
    • 3
  1. 1.Coral Genomics GroupJames Cook UniversityTownsvilleAustralia
  2. 2.ARC Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleAustralia
  3. 3.Australian Institute of Marine ScienceTownsville MCAustralia
  4. 4.ARC Centre for the Molecular Genetics of Development, Research School of Biological SciencesAustralian National UniversityCanberraAustralia
  5. 5.Mathematical Science InstituteAustralian National UniversityCanberraAustralia
  6. 6.Aquaculture Genetics GroupJames Cook UniversityTownsvilleAustralia
  7. 7.Centre for Marine StudiesUniversity of QueenslandSt LuciaAustralia