Phylogeography of the pelagic fish <i>Seriola lalandi</i> at different scales: confirmation of inter-ocean population structure and evaluation of southern African genetic diversity

The study investigated the global and regional phylogeography of the yellowtail kingfish <i>Seriola lalandi</i> by examining genetic diversity and population genetic structure of this species at inter-and intra-ocean level and on a regional scale. DNA fragments of two mitochondrial genes, cytochrome <i>b</i> (Cytb) and cytochrome <i>c</i> oxidase subunit I (COI) and one nuclear gene, recombination activating gene 1 (RAG1), were sequenced to investigate the global-scale phylogeography of this species. The population genetic structure within the South Pacific, as well as along the South African coastline, was examined further using six microsatellite markers. Three distinct clades were identified for <i>S. lalandi</i>, which correspond with previously described subspecies of the North-East Pacific, North-West Pacific and the Southern Hemisphere. Within the latter, additional divergence was observed between the South Pacific and the South-East Atlantic regions. Divergence estimates were indicative of a Pacific origin for <i>S. lalandi</i> populations, because of Pleistocene vicariant events. Microsatellite analyses revealed overall significant genetic differentiation between South African and South Pacific samples. This corroborates recent findings on the global phylogeography of the species. No population differentiation was observed within South Africa, indicating high levels of gene flow.

本研究针对黄条鰤（Seriola lalandi）的全球及区域系统地理学展开探究，通过跨洋、洋内及区域尺度的分析，解析该物种的遗传多样性与种群遗传结构。为探究该物种的全球尺度系统地理学格局，研究人员对两段线粒体基因片段——细胞色素b（cytochrome b, Cytb）与细胞色素c氧化酶亚基I（cytochrome c oxidase subunit I, COI），以及一段核基因重组激活基因1（recombination activating gene 1, RAG1）进行了测序。为进一步解析南太平洋及南非沿岸海域的种群遗传结构，本研究采用6个微卫星标记（microsatellite markers）开展分析。研究共鉴定出黄条鰤的3个独立演化支，分别对应此前已报道的东北太平洋、西北太平洋及南半球亚种。其中南半球演化支内，南太平洋与东南大西洋区域间还存在额外的遗传分化。基于分化时间估算结果，黄条鰤种群起源于太平洋，这一结论与更新世时期的隔离分化事件相契合。微卫星分析显示，南非与南太平洋的样本间存在显著的整体遗传分化，这与该物种全球系统地理学的近期研究结果相互印证。南非海域内部未观测到种群遗传分化，表明该区域内存在高水平的基因交流。

搜集汇总

背景与挑战

背景概述

该数据集基于黄尾鰤（Seriola lalandi）的系统地理学研究，通过分析线粒体和核基因序列以及微卫星标记，确认了跨洋种群结构，识别出三个主要进化支，并揭示了南非与南太平洋之间的遗传分化，同时南非内部基因流较高。