Chen Baohua, Zhou Zhixiong, Shi Yue, Gong Jie, Li Chengyu, Zhou Tao, Li Yun, Zhang Dianchang, Xu Peng
State Key Laboratory of Mariculture Breeding, College of Ocean and Earth Sciences Xiamen University Xiamen China.
Shenzhen Research Institute of Xiamen University Shenzhen China.
Evol Appl. 2023 Apr 27;16(5):1029-1043. doi: 10.1111/eva.13551. eCollection 2023 May.
Consideration of the thermal adaptation of species is essential in both evolutionary biology and climate-change biology because it frequently leads to latitudinal gradients of various phenotypes among populations. The spotted sea bass () has a broad latitudinal distribution range along the marginal seas of the Northwest Pacific and thus provides an excellent teleost model for population genetic and climate adaptation studies. We generated over 8.57 million SNP loci using whole-genome resequencing from 100 samples collected at 14 geographic sites (five or ten samples per site). We estimated the genetic structure of the sampled fish and clustered them into three highly differentiated populations. The genetic differentiation pattern estimated by multivariable models combining geographic distance and sea surface temperature differences suggests that isolation by distance and isolation by environment both have significant effects on this species. Further investigation of genome-wide evolutionary signatures of climate adaptation identified many genes related to growth, muscle contraction, and vision that are under positive natural selection. Moreover, the contrasting patterns of natural selection in high-latitude and low-latitude populations prompted different strategies of trade-offs between growth rate and other traits that may play an essential role in adaptation to different local climates. Our results offer an opportunity to better understand the genetic basis of the phenotypic variation in eurythermal fishes inhabiting different climatic regions.
在进化生物学和气候变化生物学中，考虑物种的热适应性都至关重要，因为它常常导致种群间各种表型的纬度梯度变化。花鲈（）在西北太平洋边缘海域具有广泛的纬度分布范围，因此为种群遗传学和气候适应性研究提供了一个出色的硬骨鱼模型。我们通过对从14个地理位点（每个位点采集5个或10个样本）收集的100个样本进行全基因组重测序，生成了超过857万个单核苷酸多态性（SNP）位点。我们估计了所采样鱼类的遗传结构，并将它们聚类为三个高度分化的种群。结合地理距离和海面温度差异的多变量模型估计的遗传分化模式表明，距离隔离和环境隔离对该物种都有显著影响。对气候适应性的全基因组进化特征的进一步研究发现了许多与生长、肌肉收缩和视觉相关的基因正处于正自然选择之下。此外，高纬度和低纬度种群中自然选择的对比模式促使在生长速率和其他可能在适应不同当地气候中起重要作用的性状之间采取不同的权衡策略。我们的结果为更好地理解栖息在不同气候区域的广温性鱼类表型变异的遗传基础提供了契机。
