Data from: Genetic and epigenetic variation in Spartina alterniflora following the Deepwater Horizon oil spill

Catastrophic events offer unique opportunities to study rapid population response to stress in natural settings. In concert with genetic variation, epigenetic mechanisms like DNA methylation may offer a mechanism of rapid response to organisms facing severe environmental challenges, and contribute to the high resilience of species like Spartina alterniflora, a foundation salt marsh grass which shows resilience to strong environmental disturbance. In 2010, the Deepwater Horizon oil spill devastated large portions of the coastline along the Gulf of Mexico. Following the spill, we simultaneously examined the genetic and epigenetic structure of recovering populations of S. alterniflora to oil exposure. We quantified genetic and DNA methylation variation using AFLP and MS-AFLP to test the hypothesis that response to oil exposure in S. alterniflora resulted in genetically and epigenetically based population differentiation. We found high genetic and epigenetic variation within and among sites, and found significant genetic differentiation between contaminated and uncontaminated sites, which may reflect non-random mortality in response to oil exposure. Additionally, despite a lack of genome wide patterns in DNA methylation between contaminated and uncontaminated sites, we found five MS-AFLP loci (12% of polymorphic MS-AFLP loci) that were correlated with oil exposure. Overall, our findings support genetically based differentiation correlated to exposure to the oil spill in this system, but also suggest a potential role for epigenetic mechanisms in population differentiation.极端灾害事件为研究自然环境下种群对胁迫的快速响应提供了独特契机。与遗传变异协同作用的表观遗传调控机制（如DNA甲基化），可为面临极端环境挑战的生物提供快速响应途径，并助力互花米草（Spartina alterniflora）这类对强环境扰动具有高恢复力的基础盐沼草本物种维持种群抗逆性。2010年，深水地平线（Deepwater Horizon）原油泄漏事件重创了墨西哥湾沿岸大片海岸线。此次泄漏事件发生后，我们同步研究了受原油暴露影响的互花米草恢复种群的遗传与表观遗传结构。我们采用扩增片段长度多态性（AFLP）与甲基化敏感扩增片段长度多态性（MS-AFLP）技术量化遗传与DNA甲基化变异，以验证如下假说：互花米草对原油暴露的响应可导致基于遗传与表观遗传机制的种群分化。研究发现，各采样点内部及不同采样点间均存在较高的遗传与表观遗传变异，且受污染与未受污染站点间存在显著的遗传分化，这或反映了种群在应对原油暴露时发生了非随机性死亡。此外，尽管受污染与未受污染站点间未出现全基因组水平的DNA甲基化模式差异，但我们发现5个MS-AFLP位点（占多态性MS-AFLP位点的12%）与原油暴露存在显著相关性。综上，本研究结果证实了该系统中与原油泄漏暴露相关的遗传分化，同时也表明表观遗传机制在种群分化中可能发挥潜在作用。