PCSGA 2018: Influence of Ocean Acidification on the Epigenome of Oyster Reproductive Tissue

Epigenetic modification, specifically DNA methylation, is one possible mechanism for transgenerational plasticity. Before inheritance of methylation patterns can be characterized we need a better understanding of how environmental change modifies the parental epigenome. To examine the influence of experimental ocean acidification on Eastern oyster (Crassostrea virginica) gonad tissue, oysters were exposed to control (400 µatm) or high (2800 µatm) pCO2 conditions for four weeks. DNA from reproductive tissue was isolated from five oysters per treatment, then subjected to bisulfite treatment and DNA sequencing. Over 400 differentially methylated loci were identified primarily overlapping with gene bodies. A majority of these loci were in mRNA coding regions. The predicted function of genes containing differentially methylated loci location suggests a role for DNA methylation in acclimating to adverse conditions. Understanding how experimental ocean acidification conditions modify the oyster epigenome, and if these modifications are inherited, will allow for a better understanding of how ecosystems will response to environmental change.