Perdices A, Sayanda D, Coelho M M
Universidade de Lisboa, Faculdade de Ciências, Departamento de Biologia Animal, Centro de Biologia Ambiental, Bloco C-2, 3 Piso, Campo Grande, 1749-016 Lisbon, Portugal.
Mol Phylogenet Evol. 2005 Dec;37(3):920-7. doi: 10.1016/j.ympev.2005.04.020. Epub 2005 Jun 17.
We describe the phylogeographic structure of 28 Chinese populations of the cyprinid Opsariichthys bidens across three main Chinese river drainages. Our study is based on the phylogenetic analysis of the complete mitochondrial cytochrome b gene (1140 bp). We combined this analysis with population processes inferred from nested clade analysis (NCA) and mismatch distributions. Both analyses showed that Chinese O. bidens consists of five mtDNA lineages (Opsariichthys 1-5) with high genetic divergence among them. Molecular divergences (TrN+G) higher than 20% among the Opsariichthys 1-5 mtDNA lineages suggest a taxonomic underestimation at the species level. About 92% of the genetic variance among samples was explained by differences among Opsariichthys mtDNA lineages. Drainage-restricted haplotypes with high frequencies and moderate nucleotide diversity show that Opsariichthys populations have evolved independently. NCA results were congruent with the phylogeny, and unimodal mismatch distributions with negative Tajima's D values suggest population expansions in some Opsariichthys lineages. The phylogeographic structure of the Opsariichthys 1-5 mtDNA lineages appears to be related to their long-term interruption of gene flow (theta(ST)>0.97). Our results suggested that fragmentation of ancestral ranges might have caused Opsariichthys diversification in Chinese waters. However, current distribution of common haplotypes across the Yangtze and Pearl drainages suggests a recent river connection that could have favoured gene flow across drainages. Overall, the results indicated that the richness of current Asian widespread species might have been underestimated, and that the cyprinid populations of O. bidens in the Yangtze, Pearl and Hai He drainages may correspond to five species.
我们描述了分布于中国三大主要河流流域的28个中华倒刺鲃种群的系统地理学结构。我们的研究基于对完整线粒体细胞色素b基因（1140 bp）的系统发育分析。我们将此分析与从嵌套分支分析（NCA）和失配分布推断出的种群过程相结合。两种分析均表明，中国的中华倒刺鲃由五个线粒体DNA谱系（倒刺鲃1 - 5）组成，它们之间存在高度的遗传差异。倒刺鲃1 - 5线粒体DNA谱系之间高于20%的分子差异（TrN + G）表明在物种水平上分类存在低估。样本间约92%的遗传变异可由倒刺鲃线粒体DNA谱系间的差异解释。具有高频率和中等核苷酸多样性的受流域限制的单倍型表明倒刺鲃种群是独立进化的。NCA结果与系统发育一致，单峰失配分布和负的Tajima's D值表明一些倒刺鲃谱系存在种群扩张。倒刺鲃1 - 5线粒体DNA谱系的系统地理学结构似乎与其长期的基因流中断（theta(ST)>0.97）有关。我们的结果表明，祖先分布范围的破碎化可能导致了中华倒刺鲃在中国水域的多样化。然而，目前长江和珠江流域常见单倍型的分布表明最近存在河流连通，这可能有利于跨流域的基因流动。总体而言，结果表明目前亚洲广泛分布物种的丰富度可能被低估，长江、珠江和海河流域的中华倒刺鲃种群可能对应五个物种。
