Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, USA.
J Hered. 2012 Mar-Apr;103(2):153-65. doi: 10.1093/jhered/esr083. Epub 2011 Sep 1.
Population genetic characteristics are shaped by the life-history traits of organisms and the geologic history of their habitat. This study provides a neutral framework for understanding the population dynamics and opportunities for selection in Semibalanus balanoides, a species that figures prominently in ecological and evolutionary studies in the Atlantic intertidal. We used mitochondrial DNA (mtDNA) control region (N = 131) and microsatellite markers (∼40 individuals/site/locus) to survey populations of the broadly dispersing acorn barnacle from 8 sites spanning 800 km of North American coast and 1 site in Europe. Patterns of mtDNA sequence evolution were consistent with larger population sizes in Europe and population expansion at the conclusion of the last ice age, approximately 20 000 years ago, in North America. A significant portion of mitochondrial diversity was partitioned between the continents (ϕ(ST) = 0.281), but there was only weak structure observed from mtDNA within North America. Microsatellites showed significant structuring between the continents (F(ST) = 0.021) as well as within North America (F(ST) = 0.013). Isolation by distance in North America was largely driven by a split between populations south of Cape Cod and all others (P < 10(-4)). The glacial events responsible for generating allelic diversity at mtDNA and microsatellites may also be responsible for generating selectable variation at metabolic enzymes in S. balanoides.
人口遗传特征是由生物体的生活史特征和其栖息地的地质历史所塑造的。本研究为了解 Semibalanus balanoides 的种群动态和选择机会提供了一个中立的框架，该物种在大西洋潮间带的生态和进化研究中占据重要地位。我们使用线粒体 DNA（mtDNA）控制区（N = 131）和微卫星标记（每个位点/基因座约 40 个个体）对广泛分布的橡果藤壶进行了种群调查，这些种群来自北美海岸 800 公里范围内的 8 个地点和欧洲的 1 个地点。mtDNA 序列进化模式与欧洲较大的种群规模以及约 2 万年前末次冰期结束时北美的种群扩张一致。大量的线粒体多样性在各大洲之间存在差异（ϕ(ST) = 0.281），但在北美的 mtDNA 内仅观察到微弱的结构。微卫星显示各大洲之间存在显著的结构（F(ST) = 0.021）以及北美的结构（F(ST) = 0.013）。北美的隔离距离主要由科德角以南的种群与其他所有种群之间的分裂驱动（P < 10(-4)）。导致 mtDNA 和微卫星等位基因多样性产生的冰川事件，也可能导致 S. balanoides 代谢酶的可选择变异产生。
