PT  - JOURNAL ARTICLE
AU  - Mariano Alvarez
AU  - Marta Robertson
AU  - Thomas van Gurp
AU  - Niels Wagemaker
AU  - Delphine Giraud
AU  - Malika L. Ainouche
AU  - Armel Salmon
AU  - Koen J. F. Verhoeven
AU  - Christina L. Richards
TI  - Reduced representation characterization of genetic and epigenetic differentiation to oil pollution in the foundation plant <em>Spartina alterniflora</em>
AID  - 10.1101/426569
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 426569
4099  - http://biorxiv.org/content/early/2020/01/14/426569.short
4100  - http://biorxiv.org/content/early/2020/01/14/426569.full
AB  - Theory predicts that environmental challenges can shape the composition of populations, which is manifest at the molecular level. Previously, we demonstrated that oil pollution affected gene expression patterns and altered genetic variation in natural populations of the foundation salt marsh grass, Spartina alterniflora. Here, we used a reduced representation bisulfite sequencing approach, epigenotyping by sequencing (epiGBS), to examine relationships among DNA sequence, DNA methylation, gene expression, and exposure to oil pollution. We documented genetic and methylation differentiation between oil-exposed and unexposed populations, suggesting that the Deepwater Horizon oil spill may have selected on genetic variation, and either selected on epigenetic variation or induced particular epigenotypes and expression patterns in exposed compared to unexposed populations. In support of the potential for differential response to the Deepwater Horizon oil spill, we demonstrate genotypic differences in response to oil under controlled conditions. Overall, these findings demonstrate genetic variation, epigenetic variation and gene expression are correlated to exposure to oil pollution, which may all contribute to the response to environmental stress.