Bernatchez L, Guyomard R, Bonhomme F
Laboratoire Génome et Populations, (CNRS URA 1493), Université Montpellier II, Jouy-en-Josas, France.
Mol Ecol. 1992 Oct;1(3):161-73. doi: 10.1111/j.1365-294x.1992.tb00172.x.
Throughout its natural range, the brown trout Salmo trutta L. exhibits a complex pattern of morphological and life-history variation. This has led to considerable taxonomic confusion, hampering the understanding of the evolutionary history of the species. To document the phylogenetic relationships among morphologically and geographically remote brown trout populations across western Europe, we determined the DNA sequence variation in segments of the mitochondrial control region for 151 individuals representing 24 populations. DNA was prepared for double-stranded sequencing by the polymerase chain reaction (PCR). Twenty-one variable nucleotide positions within a 640-bp fragment surveyed defined 12 genotypes differing by a mean of 7 nucleotide substitutions (range 1-12). Five major phylogenetic assemblages differing by mean sequence divergence estimates of 0.96 to 1.44% were identified. These groupings exhibited a strong spatial partitioning but lacked congruence with either ecological or morphological differentiation. Complete mitochondrial DNA (mtDNA) monomorphism across all Atlantic basin populations contrasted with the high interdrainage genetic diversity observed in more southerly populations. This study exemplified the usefulness of mitochondrial DNA sequence analysis for estimating phylogenetic relationships within S. trutta populations.
在其整个自然分布范围内，褐鳟（Salmo trutta L.）呈现出形态和生活史变异的复杂模式。这导致了相当大的分类学混乱，阻碍了对该物种进化历史的理解。为了记录西欧各地形态和地理上遥远的褐鳟种群之间的系统发育关系，我们测定了代表24个种群的151个个体线粒体控制区片段的DNA序列变异。通过聚合酶链反应（PCR）制备用于双链测序的DNA。在所检测的640个碱基对片段内的21个可变核苷酸位置定义了12种基因型，平均相差7个核苷酸替代（范围为1至12）。鉴定出五个主要的系统发育组合，平均序列分歧估计值相差0.96%至1.44%。这些分组表现出强烈的空间划分，但与生态或形态分化不一致。所有大西洋流域种群的线粒体DNA（mtDNA）完全单态性与更南部种群中观察到的高流域间遗传多样性形成对比。这项研究例证了线粒体DNA序列分析在估计褐鳟种群内系统发育关系方面的有用性。
