Van Wyngaarden Mallory, Snelgrove Paul V R, DiBacco Claudio, Hamilton Lorraine C, Rodríguez-Ezpeleta Naiara, Zhan Luyao, Beiko Robert G, Bradbury Ian R
Department of Biology Memorial University of Newfoundland St. John's NL Canada.
Department of Ocean Sciences Memorial University of Newfoundland St. John's NL Canada.
Ecol Evol. 2018 Feb 11;8(5):2824-2841. doi: 10.1002/ece3.3846. eCollection 2018 Mar.
Environmental factors can influence diversity and population structure in marine species and accurate understanding of this influence can both improve fisheries management and help predict responses to environmental change. We used 7163 SNPs derived from restriction site-associated DNA sequencing genotyped in 245 individuals of the economically important sea scallop, , to evaluate the correlations between oceanographic variation and a previously identified latitudinal genomic cline. Sea scallops span a broad latitudinal area (>10 degrees), and we hypothesized that climatic variation significantly drives clinal trends in allele frequency. Using a large environmental dataset, including temperature, salinity, chlorophyll a, and nutrient concentrations, we identified a suite of SNPs (285-621, depending on analysis and environmental dataset) potentially under selection through correlations with environmental variation. Principal components analysis of different outlier SNPs and environmental datasets revealed similar northern and southern clusters, with significant associations between the first axes of each ( = .66-.79). Multivariate redundancy analysis of outlier SNPs and the environmental principal components indicated that environmental factors explained more than 32% of the variance. Similarly, multiple linear regressions and random-forest analysis identified winter average and minimum ocean temperatures as significant parameters in the link between genetic and environmental variation. This work indicates that oceanographic variation is associated with the observed genomic cline in this species and that seasonal periods of extreme cold may restrict gene flow along a latitudinal gradient in this marine benthic bivalve. Incorporating this finding into management may improve accuracy of management strategies and future predictions.
环境因素会影响海洋物种的多样性和种群结构，准确理解这种影响既能改善渔业管理，又有助于预测对环境变化的响应。我们利用从限制性内切酶相关DNA测序中获得的7163个单核苷酸多态性（SNP），对经济价值重大的海扇贝的245个个体进行基因分型，以评估海洋学变化与先前确定的纬度基因组渐变之间的相关性。海扇贝分布在广阔的纬度区域（超过10度），我们假设气候变化显著驱动等位基因频率的渐变趋势。利用一个包含温度、盐度、叶绿素a和营养浓度的大型环境数据集，我们通过与环境变化的相关性确定了一组可能处于选择之下的SNP（285 - 621个，具体取决于分析和环境数据集）。对不同的异常SNP和环境数据集进行主成分分析，揭示了相似的北部和南部聚类，每个聚类的第一轴之间存在显著关联（r = 0.66 - 0.79）。对异常SNP和环境主成分进行多变量冗余分析表明，环境因素解释了超过32%的变异。同样，多元线性回归和随机森林分析确定冬季平均海洋温度和最低海洋温度是遗传与环境变化之间联系的重要参数。这项工作表明，海洋学变化与该物种中观察到的基因组渐变有关，极端寒冷的季节可能会限制这种海洋底栖双壳类动物沿纬度梯度的基因流动。将这一发现纳入管理可能会提高管理策略和未来预测的准确性。
