Research article

Microarray analysis identifies candidate genes for key roles in coral development

Lauretta C Grasso¹ , John Maindonald² , Stephen Rudd³ , David C Hayward¹ , Robert Saint¹ , David J Miller⁴ and Eldon E Ball¹

¹Centre for the Molecular Genetics of Development, Research School of Biological Sciences, Australian National University, Canberra, Australia

²Centre for Mathematics and its Applications, Mathematical Sciences Institute, Building 27, Australian National University, Australia

³Turku Centre for Biotechnology, Tykisokatu 6, 20521 Turku, Finland

⁴Centre for Molecular Genetics of Development & ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia

author email corresponding author email

BMC Genomics 2008, 9:540doi:10.1186/1471-2164-9-540

Published:	14 November 2008

Abstract

Background

Anthozoan cnidarians are amongst the simplest animals at the tissue level of organization, but are surprisingly complex and vertebrate-like in terms of gene repertoire. As major components of tropical reef ecosystems, the stony corals are anthozoans of particular ecological significance. To better understand the molecular bases of both cnidarian development in general and coral-specific processes such as skeletogenesis and symbiont acquisition, microarray analysis was carried out through the period of early development – when skeletogenesis is initiated, and symbionts are first acquired.

Results

Of 5081 unique peptide coding genes, 1084 were differentially expressed (P ≤ 0.05) in comparisons between four different stages of coral development, spanning key developmental transitions. Genes of likely relevance to the processes of settlement, metamorphosis, calcification and interaction with symbionts were characterised further and their spatial expression patterns investigated using whole-mount in situ hybridization.

Conclusion

This study is the first large-scale investigation of developmental gene expression for any cnidarian, and has provided candidate genes for key roles in many aspects of coral biology, including calcification, metamorphosis and symbiont uptake. One surprising finding is that some of these genes have clear counterparts in higher animals but are not present in the closely-related sea anemone Nematostella. Secondly, coral-specific processes (i.e. traits which distinguish corals from their close relatives) may be analogous to similar processes in distantly related organisms. This first large-scale application of microarray analysis demonstrates the potential of this approach for investigating many aspects of coral biology, including the effects of stress and disease.