Epigenetic patterns associated with an ascidian invasion: a comparison of closely related clades in their native and introduced ranges
Epigenetic patterns associated with an ascidian invasion: a comparison of closely related clades in their native and introduced ranges
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DOI：
10.1038/s41598-019-49813-7
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发表时间：
2019-10-03
影响因子：
4.6
通讯作者：
Smith, Kirsty F.
中科院分区：
文献类型：
--
作者：
Hawes, Nicola A.;Amadorou, Achira;Smith, Kirsty F.
环境诱导的表观遗传修饰被认为是入侵物种快速适应性进化的一种机制。Didemnum vexillum是一种入侵的殖民海鞘，已在世界各地的许多沿海沃茨建立。系统发育分析表明，D. vexillum种群由两个不同的分支组成; Glade B似乎仅限于本地范围（日本），而Glade A在世界各地的许多地区，包括新西兰。D. vexillum林地A表明，它可能是本质上更具侵略性比林地B，尽管低水平的遗传多样性相比，从本地地区的人口。本研究探讨了D. vexillum进化枝A表现出与侵袭性相关的表观遗传特征（特别是DNA甲基化的差异）。在引入的进化枝A菌落之间，以及在天然范围内的进化枝A和B之间，全局DNA甲基化模式显著不同。引入的菌落也显示出DNA甲基化水平的显着降低，这可能是增加表型可塑性的机制。高水平的DNA甲基化多样性保持在引进的人口，尽管减少了遗传多样性水平，这可能使入侵种群迅速应对新环境的变化。在入侵过程中诱导的表观遗传变化可以提供一种快速适应的手段，尽管在引入的种群中的遗传变异水平较低。
Environmentally induced epigenetic modifications have been proposed as one mechanism underlying rapid adaptive evolution of invasive species. Didemnum vexillum is an invasive colonial ascidian that has established in many coastal waters worldwide. Phylogenetic analyses have revealed that D. vexillum populations consist of two distinct clades; Glade B appears to be restricted to the native range (Japan), whereas Glade A is found in many regions throughout the world, including New Zealand. The spread of D. vexillum Glade A suggests that it might be intrinsically more invasive than Glade B, despite low levels of genetic diversity compared to populations from the native region. This study investigated whether D. vexillum cladeA exhibits epigenetic signatures (specifically differences in DNA methylation) associated with invasiveness. Global DNA methylation patterns were significantly different between introduced cladeA colonies, and both clades A and B in the native range. Introduced colonies also showed a significant reduction in DNA methylation levels, which could be a mechanism for increasing phenotypic plasticity. High levels of DNA methylation diversity were maintained in the introduced population, despite reduced levels of genetic diversity, which may allow invasive populations to respond quickly to changes in new environments. Epigenetic changes induced during the invasion process could provide a means for rapid adaptation despite low levels of genetic variation in introduced populations.