Durand J D, Unlü E, Doadrio I, Pipoyan S, Templeton A R
CNRS-ESA 5023 Ecologie des Hydrosystèmes Fluviaux, Université Claude Bernard Lyon 1, Villeurbanne, France.
Proc Biol Sci. 2000 Aug 22;267(1453):1687-97. doi: 10.1098/rspb.2000.1196.
The phylogenetic relationships of 492 chub (Leuciscus cephalus) belonging to 89 populations across the species' range were assessed using 600 base pairs of cytochrome b. Furthermore, nine species belonging to the L. cephalus complex were also analysed (over the whole cytochrome b) in order to test potential allopatric hybridization with L. cephalus sensu stricto (i.e. the chub). Our results show that the chub includes four highly divergent lineages descending from a quick radiation that took place three million years ago. The geographical distribution of these lineages and results of the nested clade analysis indicated that the chub may have originated from Mesopotamia. Chub radiation probably occurred during an important vicariant event such as the isolation of numerous Turkish river systems, a consequence of the uplift of the Anatolian Plateau (formerly covered by a broad inland lake). Dispersion of these lineages arose from the changes in the European hydrographic network and, thus, the chub and endemic species of the L. cephalus complex met by secondary contacts. Our results show several patterns of introgression, from Leuciscus lepidus fully introgressed by chub mitochondrial DNA to Leuciscus borysthenicus where no introgression at all was detected. We assume that these hybridization events might constitute an important evolutionary process for the settlement of the chub in new environments in the Mediterranean area.
利用细胞色素b的600个碱基对，评估了分布在该物种整个分布范围内的89个种群的492条圆腹雅罗鱼（Leuciscus cephalus）的系统发育关系。此外，还对属于圆腹雅罗鱼复合体的9个物种（分析了整个细胞色素b序列）进行了分析，以测试与狭义圆腹雅罗鱼（即圆腹雅罗鱼）潜在的异域杂交情况。我们的结果表明，圆腹雅罗鱼包括四个高度分化的谱系，它们源自三百万年前快速辐射形成的谱系。这些谱系的地理分布以及嵌套分支分析的结果表明，圆腹雅罗鱼可能起源于美索不达米亚。圆腹雅罗鱼的辐射可能发生在一次重要的替代事件期间，比如众多土耳其河流系统的隔离，这是安纳托利亚高原隆升（以前被一个广阔的内陆湖覆盖）的结果。这些谱系的扩散源于欧洲水系网络的变化，因此，圆腹雅罗鱼与圆腹雅罗鱼复合体的特有物种通过二次接触相遇。我们的结果显示了几种渐渗模式，从完全被圆腹雅罗鱼线粒体DNA渐渗的欧洲雅罗鱼（Leuciscus lepidus）到完全未检测到渐渗的伏尔加雅罗鱼（Leuciscus borysthenicus）。我们认为，这些杂交事件可能是圆腹雅罗鱼在地中海地区新环境中定居的一个重要进化过程。
