Data from: Germline DNA methylation in reef corals: patterns and potential roles in response to environmental change

DNA methylation is an epigenetic mark that plays an inadequately
understood role in gene regulation, particularly in non-model species.
Because it can be influenced by the environment, DNA methylation may
contribute to the ability of organisms to acclimatize and adapt to
environmental change. We evaluated the distribution of gene body
methylation in reef-building corals, a group of organisms facing
significant environmental threats. Gene body methylation in six species of
corals was inferred from in silico transcriptome analysis of CpG O/E, an
estimate of germline DNA methylation that is highly correlated with
patterns of methylation enrichment. Consistent with what has been
documented in most other invertebrates, all corals exhibited bimodal
distributions of germline methylation suggestive of distinct fractions of
genes with high and low levels of methylation. The hypermethylated
fractions were enriched with genes with housekeeping functions, while
genes with inducible functions were highly represented in the
hypomethylated fractions. High transcript abundance was associated with
intermediate levels of methylation. In three of the coral species, we
found that genes differentially expressed in response to thermal stress
and ocean acidification exhibited significantly lower levels of
methylation. These results support a link between gene body
hypomethylation and transcriptional plasticity that may point to a role of
DNA methylation in the response of corals to environmental change.