Koskinen M T, Ranta E, Piironen J, Veselov A, Titov S, Haugen T O, Nilsson J, Carlstein M, Primmer C R
Integrative Ecology Unit, Department of Ecology and Systematics, PO Box 17, 00014 University of Helsinki, Helsinki, Finland.
Mol Ecol. 2000 Oct;9(10):1609-24. doi: 10.1046/j.1365-294x.2000.01065.x.
In stark contrast to other species within the Salmonidae family, phylogeographic information on European grayling, Thymallus thymallus, is virtually nonexistent. In this paper, we utilized mitochondrial DNA polymerase chain reaction-restriction fragment length polymorphism (mtDNA PCR-RFLP) and sequence variation to infer the postglacial dispersal routes of T. thymallus into and within northern Europe, and to locate geographically, potential evolutionarily distinct populations. Mitochondrial analyses revealed a total of 27 T. thymallus haplotypes which clustered into three distinct lineages. Average pairwise interlineage divergence was four and nine times higher than average intralineage divergence for RFLP and sequence data, respectively. Two European grayling individuals from the easternmost sample in Russia exhibited haplotypes more genetically diverged from any T. thymallus haplotype than T. arcticus haplotype, and suggested that hybridization/introgression zone of these two sister species may extend much further west than previously thought. Geographic division of the lineages was generally very clear with northern Europe comprising of two genetically differentiated areas: (i) Finland, Estonia and north-western Russia; and (ii) central Germany, Poland and western Fennoscandia. Average interpopulation divergence in North European T. thymallus was 10 times higher than that observed in a recent mtDNA study of North American T. arcticus. We conclude that (i) North European T. thymallus populations have survived dramatic Pleistocene temperature oscillations and originate from ancient eastern and central European refugia; (ii) genetic divergence of population groups within northern Europe is substantial and geographically distinct; and (iii) the remainder of Europe harbours additional differentiated assemblages that likely descend from a Danubian refugium. These findings should provide useful information for developing appropriate conservation strategies for European grayling and exemplify a case with a clear need for multinational co-operation for managing and conserving biodiversity.
与鲑科家族中的其他物种形成鲜明对比的是，欧洲河鳟（Thymallus thymallus）的系统地理学信息几乎不存在。在本文中，我们利用线粒体DNA聚合酶链反应-限制性片段长度多态性（mtDNA PCR-RFLP）和序列变异来推断欧洲河鳟在末次冰盛期后扩散至北欧及在北欧内部的扩散路线，并在地理上定位潜在的进化上不同的种群。线粒体分析共揭示了27种欧洲河鳟单倍型，这些单倍型聚为三个不同的谱系。对于RFLP和序列数据，平均谱系间成对差异分别比平均谱系内差异高4倍和9倍。来自俄罗斯最东部样本的两条欧洲河鳟个体所展现出的单倍型，在遗传上比任何欧洲河鳟单倍型与北极河鳟（T. arcticus）单倍型的差异都更大，这表明这两个姐妹物种的杂交/基因渗入区可能比之前认为的向西延伸得更远。谱系的地理划分总体上非常清晰，北欧由两个遗传上有差异的区域组成：（i）芬兰、爱沙尼亚和俄罗斯西北部；以及（ii）德国中部、波兰和斯堪的纳维亚半岛西部。北欧欧洲河鳟的平均种群间差异比最近一项对北美北极河鳟的线粒体DNA研究中观察到的差异高10倍。我们得出结论：（i）北欧欧洲河鳟种群在更新世剧烈的温度波动中存活下来，起源于古代欧洲东部和中部的避难所；（ii）北欧内部种群组的遗传差异很大且在地理上有明显区分；（iii）欧洲其他地区拥有可能源自多瑙河避难所的其他分化组合。这些发现应为制定欧洲河鳟的适当保护策略提供有用信息，并例证了一个显然需要跨国合作来管理和保护生物多样性的案例。
