Meeting Abstract
Populations of eastern oysters (Crassostrea virginica) in the Northern Gulf of Mexico will be challenged by predicted changes in ocean temperature and salinity. As environments change a combination of phenotypic plasticity and local adaptations will be important mechanisms that may allow one population to persist and not another. Recent advancements in the use of reduced representation bisulfite sequencing and the release of a reference genome for C. virginica provides new opportunities to explore the extent to which DNA methylation is shaped by the environment. Recent evidence suggests that there are population specific patterns in DNA methylation in C. virginica and that DNA methylation is significantly correlated with variability in gene expression. In this study we have explored changes in DNA methylation between 2 populations of C. virginica collected from a high and a low salinity site along coastal Louisiana. Crosses within each population were conducted at Grand Isle Hatchery (LA) and the progeny were out-planted at either a medium-high salinity site (Grand Isle, LA; 19.2 psu) or at a low-salinity site (Chauvin, LA; 9.7 psu). To test for the effects of rearing environment and dermo infection intensity on DNA methylation we sampled 20 oysters for each population from each site after 1 year. We assessed changes in DNA methylation using reduced representation bisulfite sequencing (RRBS) and focused our comparisons on changes in methylation within a population but between out-plant sites and for dermo infection between populations within a site. This approach provides the opportunity to explore the extent to which genotype, infection intensity, and environment influence DNA methylation patterns in C. virginica.
