Data from: Genetic relationships between Atlantic and Pacific populations of the notothenioid fish Eleginops maclovinus: the footprints of Quaternary glaciations in Patagonia

The genetic relationships between the Pacific and the Atlantic populations of marine costal biota in Southern South America have been analyzed in few studies, most of them relying on a single mitochondrial locus. We analyzed ten polymorphic microsatellite loci, isolated from a dinucleotide-enriched E. maclovinus genomic library, in a total of 240 individuals (48 from each of five sampled sites: two Atlantic, two Pacific and one in Beagle Channel). The results were contrasted against a previous work on the same species with mtDNA. Observed heterozygosity within localities ranged from 0.85 to 0.88 and the highest overall number of alleles was observed at the northernmost locality on the Pacific side (Concepción) but no clear geographic pattern arose from the data. On the other hand, the number of private alleles was negatively correlated with latitude (Spearman's rs test, p = 0.017). Among-population variance was low but significant (1.35 %; p < 0.0001, AMOVA) and low genetic differentiation between populations was observed (pairwise FST values ranged from 0 to 0.021). A Mantel test reveled a significant correlation between geographic distances and FST (r = 0.56, p = 0.047). This could be partially accounted for the Atlantic vs Pacific population differentiation detected in three different analyses (Structure, SAMOVA and a population phylogeny). The observed pattern is compatible with a history of separation into two glacial refugia, which was better captured by the multilocus microsatellite data than by the mtDNA analysis.

南美南部太平洋与大西洋海域海洋沿岸生物种群间的遗传关系此前仅有少量研究涉及，其中绝大多数研究仅依托单个线粒体基因座（mitochondrial locus）开展分析。本研究针对从富集二核苷酸的E. maclovinus基因组文库中筛选获得的10个多态性微卫星基因座（microsatellite loci）进行遗传分型，共检测240个个体（5个采样点各48个：2个位于大西洋海域、2个位于太平洋海域，1个设于比格尔海峡（Beagle Channel））。将本研究结果与此前针对同一物种开展的线粒体DNA（mtDNA）研究进行对照。各采样点内的观测杂合度介于0.85至0.88之间；太平洋海域最北端的采样点（康塞普西翁，Concepción）观测到的总等位基因数最多，但数据未呈现明确的地理分布格局。另一方面，私有等位基因数量与纬度呈显著负相关（斯皮尔曼秩相关检验（Spearman's rs test），p=0.017）。种群间分子方差较低但具有统计学显著性（1.35%；p<0.0001，分子方差分析（Analysis of Molecular Variance, AMOVA）），且种群间遗传分化程度较弱，两两固定指数FST取值范围为0至0.021。曼特尔检验（Mantel test）结果显示，地理距离与FST值间存在显著相关性（r=0.56，p=0.047）。该结果可部分解释通过Structure、SAMOVA及种群系统发育分析三种方法检测到的大西洋与太平洋种群间的分化现象。本研究观测到的遗传模式与“种群曾分化为两处冰期避难所”的演化历史相符，且多位点微卫星数据相较线粒体DNA分析，更能精准捕捉这一演化信号。