Bernos Thaïs A, Gibelli Julie, Michaelides Sozos, Won Hari, Jeon Hyung-Bae, Marin Kia, Boguski David A, Janjua Muhammad Yamin, Gallagher Colin P, Howland Kimberly L, Fraser Dylan J
Department of Biology, Concordia University, 7141 Sherbrooke St. West, Montreal, QC, H4B 1R6, Canada.
Rubenstein Ecosystem Science Laboratory, University of Vermont, 3 College St., Burlington, VT, 05401, USA.
Sci Rep. 2024 Dec 28;14(1):30838. doi: 10.1038/s41598-024-81531-7.
Intraspecific variation is important for species' long-term persistence in changing environments. Conservation strategies targeting intraspecific variation often rely on the identification of management or policy units below the species level based on biological differences among populations. To identify management units, this paper examines intraspecific divergence of Lake Trout (Salvelinus namaycush) in Great Slave Lake (GSL), Canada, using low-coverage whole-genome sequencing data. Specifically, we evaluate genetic differentiation and assess the relationship with morphological, mitochondrial, and putatively adaptive divergence. We show that at least three and up to five genetically distinct Lake Trout populations co-occur in GSL and exhibit differences in spatial distribution and body size, with signatures of selection. However, admixture was widespread (60% of the fish) and population structure was shallow (average F = 0.022). These findings highlight that, even in the era of whole genome sequencing, identifying discrete management units to implement conservation efforts and policy can remain challenging in systems where gene flow among genetically and ecologically distinct populations is ubiquitous. To give more recognition to this complexity, management efforts should also focus on the area where adaptive variation is evident, and evolutionary acts are at play, to better protect species' resilience and adaptive potential in some natural systems.
种内变异对于物种在不断变化的环境中的长期存续至关重要。针对种内变异的保护策略通常依赖于根据种群间的生物学差异来识别物种水平以下的管理或政策单元。为了识别管理单元，本文利用低覆盖度全基因组测序数据，研究了加拿大大奴湖（GSL）中的湖鳟（Salvelinus namaycush）的种内分化情况。具体而言，我们评估了遗传分化，并评估了其与形态、线粒体以及假定的适应性分化之间的关系。我们发现，大奴湖中至少同时存在三个、至多五个遗传上不同的湖鳟种群，它们在空间分布和体型上存在差异，并具有选择特征。然而，混合现象很普遍（60%的鱼），种群结构较浅（平均F = 0.022）。这些发现凸显出，即使在全基因组测序时代，在遗传和生态上不同的种群间基因流动普遍存在的系统中，识别离散的管理单元以实施保护措施和政策仍可能具有挑战性。为了更充分认识这种复杂性，管理工作还应侧重于适应性变异明显且进化作用正在发挥的区域，以便在一些自然系统中更好地保护物种的恢复力和适应潜力。
