Influence of Ocean Acidification on Pacific Oyster (Crassostrea gigas) DNA Methylation

As negative effects of ocean acidification are experienced by coastal ecosystems, there is a growing trend to investigate the effect of ocean acidification has on multiple generations. For example, temporarily exposing adult Pacific oysters (Crassostrea gigas) to low pH prior to gametogenesis affects larval abundance. The documented effect on Pacific oyster larval abundance indicates a potential role for epigenetic modifications, specifically DNA methylation, in response to ocean acidification. To assess how ocean acidification affects the oyster epigenome, DNA was extracted from adult oysters exposed to either low pH (7.31 ± 0.02) or ambient pH (7.82 ± 0.02) conditions for seven weeks. Whole genome bisulfite sequencing was used to identify methylated regions. The predicted function of genes containing differentially methylated loci location suggests a role for DNA methylation in acclimating to adverse conditions. Understanding a possible mechanism for phenotypic plasticity and acclimation across generations is valuable when considering organismal ability to persist in the face of environmental change.