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...极端灾害事件为研究自然情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，DNA甲基化（DNA methylation）等表观遗传机制可为面临严峻环境挑战的生物提供快速响应路径，并助力互花米草（Spartina alterniflora）这类物种具备高耐受性——该物种为盐沼建群草本，对强环境扰动表现出优异适应性。2010年，深水地平线（Deepwater Horizon）漏油事件重创墨西哥湾沿岸大片海岸线。事件发生后，我们同步考察了受油污暴露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）对遗传变异与DNA甲基化变异进行量化分析，以验证如下假说：互花米草对油污暴露的响应，会引发基于遗传与表观遗传机制的种群分化。我们发现，各采样点内部及采样点间均存在较高水平的遗传与表观遗传变异……