Whitaker Justine M, Welsh Amy B, Hondorp Darryl W, Boase James C, Merovich George T, Welsh Stuart, Krueger Charles
School of Natural Resources, West Virginia University, Morgantown, West Virginia.
Division of Forestry and Natural Resources, West Virginia University, Morgantown, West Virginia.
J Fish Biol. 2018 Nov;93(5):942-951. doi: 10.1111/jfb.13804.
Lake sturgeon Acipenser fulvescens populations show a variety of movement patterns that are poorly understood. To compare two migratory phenotypes of A. fulvescens in the St. Clair River, MI, USA, multiple data types were analysed. Individual fish were classified into migratory phenotypes based on acoustic telemetry data collected 2012-2015. Acipenser fulvescens consistently showed movement from the St. Clair River upriver into Lake Huron or downriver into Lake St. Clair. The two migratory phenotypes were then compared for differences in morphometrics, genetics and epigenetics. Morphological differences based on linear measurements were not detected between phenotypes. Microsatellite data from 11 loci suggested one population with no genetic differentiation between migratory phenotypes. Our epigenetic results indicated that the migratory phenotypes are differentially methylated (P < 0.05), thus epigenetics may be associated with migratory differences in A. fulvescens. Only one restriction site was identified to be driving the differential methylation (P < 0.05). While little evidence at neutral loci occurred for genetic differentiation of A. fulvescens, DNA methylation may play a role in the observed movement pattern variation. When combined with microsatellite and morphometric analyses, our results suggested that different migratory patterns may reflect phenotypic plasticity, allowing A. fulvescens to acclimate to short-term environmental variability. Without an integrated approach, the role of epigenetics in the migratory phenotype of A. fulvescens may have been overlooked. Further characterization of migratory phenotypes could be important for management to conserve behavioural variation across the distribution of A. fulvescens and for design of stocking guidelines.
湖鲟（Acipenser fulvescens）种群呈现出多种运动模式，而人们对这些模式了解甚少。为了比较美国密歇根州圣克莱尔河中的两种湖鲟洄游表型，分析了多种数据类型。根据2012年至2015年收集的声学遥测数据，将个体鱼分类为洄游表型。湖鲟一直显示出从圣克莱尔河向上游进入休伦湖或向下游进入圣克莱尔湖的运动。然后比较了这两种洄游表型在形态测量学、遗传学和表观遗传学方面的差异。未检测到基于线性测量的表型之间的形态差异。来自11个位点的微卫星数据表明存在一个种群，洄游表型之间没有遗传分化。我们的表观遗传学结果表明，洄游表型存在差异甲基化（P < 0.05），因此表观遗传学可能与湖鲟的洄游差异有关。仅确定了一个限制位点驱动差异甲基化（P < 0.05）。虽然在中性位点几乎没有证据表明湖鲟存在遗传分化，但DNA甲基化可能在观察到的运动模式变化中起作用。结合微卫星和形态测量分析，我们的结果表明，不同的洄游模式可能反映了表型可塑性，使湖鲟能够适应短期环境变化。如果没有综合方法，表观遗传学在湖鲟洄游表型中的作用可能会被忽视。进一步表征洄游表型对于管理以保护湖鲟分布范围内的行为变异以及设计放流指南可能很重要。
