Molecular Ecology Laboratory, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.
Department of Environment and Genetics, and Research Centre for Future Landscapes, La Trobe University, Bundoora, Victoria, Australia.
Mol Ecol. 2024 Dec;33(23):e17570. doi: 10.1111/mec.17570. Epub 2024 Nov 4.
Genomic vulnerability is a measure of how much evolutionary change is required for a population to maintain optimal genotype-environment associations under projected climates. Aquatic species, and in particular migratory ectotherms, are largely underrepresented in studies of genomic vulnerability. Such species might be well equipped for tracking suitable habitat and spreading diversity that could promote adaptation to future climates. We characterised range-wide genomic diversity and genomic vulnerability in the migratory and fisheries-important golden perch (Macquaria ambigua) from Australia's expansive Murray-Darling Basin (MDB). The MDB has a steep hydroclimatic gradient and is one of the world's most variable regions in terms of climate and streamflow. Golden perch are threatened by fragmentation and obstruction of waterways, alteration of flow regimes, and a progressively hotter and drying climate. We gathered a genomic dataset of 1049 individuals from 186 MDB localities. Despite high range-wide gene flow, golden perch in the warmer, northern catchments had higher predicted vulnerability than those in the cooler, southern catchments. A new cross-validation approach showed that these predictions were insensitive to the exclusion of individual catchments. The results raise concern for populations at warm range edges, which may already be close to their thermal limits. However, a population with functional variants beneficial for climate adaptation found in the most arid and hydrologically variable catchment was predicted to be less vulnerable. Native fish management plans, such as captive breeding and stocking, should consider spatial variation in genomic vulnerability to improve conservation outcomes under climate change, even for dispersive species with high connectivity.
基因组脆弱性是衡量在预测气候下，种群维持最佳基因型-环境关联所需的进化变化程度的指标。在研究基因组脆弱性时，水生物种，特别是迁徙的变温动物，在很大程度上被低估了。这些物种可能非常适合追踪适宜的栖息地，并传播多样性，从而促进对未来气候的适应。我们描述了澳大利亚广阔的墨累-达令盆地（MDB）中迁徙和渔业重要的金黄鲈（Macquaria ambigua）的全范围基因组多样性和基因组脆弱性。MDB 具有陡峭的水文气候梯度，是世界上气候和径流量变化最大的地区之一。金黄鲈受到水道碎片化和阻塞、水流模式改变以及气候逐渐变热和干燥的威胁。我们从 186 个 MDB 地点收集了 1049 个人的基因组数据集。尽管存在广泛的全范围基因流，但温暖北部集水区的金黄鲈比寒冷南部集水区的金黄鲈预测脆弱性更高。一种新的交叉验证方法表明，这些预测不受排除个别集水区的影响。研究结果令人担忧的是，处于温暖范围边缘的种群可能已经接近其热极限。然而，在最干旱和水文变化最大的集水区中发现的对气候适应有功能变异的种群，其脆弱性预测较低。本土鱼类管理计划，如圈养繁殖和放流，应考虑基因组脆弱性的空间变化，以改善气候变化下的保护效果，即使对于具有高连通性的扩散物种也是如此。
