Meeting Abstract
In invertebrates, genes belonging to dynamically regulated functional categories appear to be less methylated than “housekeeping” genes, suggesting that DNA methylation may modulate gene expression plasticity. It has also been shown that, despite the fact that methylated cytosine is hypermutable, methylated genes show greater sequences conservation than non-methylated genes. These observations imply that gene body methylation should lead to stability at two time scales: transcriptional stability within individuals and evolutionarily stability within lineages. Here we used a combination of experimental and comparative methods to validate this hypothesis using scleractinian corals as a study system. To examine the relationship with transcriptional stability, gene expression was profiled in 30 pairs of genetically identical fragments of the coral Acropora millepora reciprocally transplanted between distinct natural habitats. Genes with weak methylation signatures were substantially more likely to demonstrate differential expression than genes with strong methylation signatures, supporting a link between gene body methylation and transcriptional stability. To examine the link with sequence conservation, we correlated the methylation signatures with synonymous substitution rates and dN/dS ratios across orthologous protein-coding sequences from five species of Acropora species.
