Genetics and Oil: Transcriptomics, Epigenetics, and Population Genomics as Tools to Understand Animal Responses to Exposure Across Different Time Scales

Exposure to oil causes basic organismal responses rooted in the genetic architecture of specific species. At the most basic level, exposure leads to immediate changes in gene expression related to xenobiotic metabolism but also changes in expression that may lead to impairment of important biological processes and abnormal development. While many responses amount to transient changes in function, some related to epigenetic gene regulation may be more permanent, persisting long after cessation of exposure. Further, some epigenetic change may be heritable, with oil-like responses persisting in later generations that were never directly exposed. Finally, exposure can create mass-mortality events that change contemporary levels of genomic variation and/or lead to selective regimes that favor individuals that carry allelic variants making them more resistant to the negative effects of oil exposure. The latter issue may be compounded if low levels of oil remain in the system leading to chronic exposure and continued selection. This chapter will review molecular techniques and “omics” tools that have allowed researchers a better understanding of the genetic underpinnings of organismal response to oil exposure, while highlighting future directions for this type of research.