Curr Biol. 2013 Aug 5;23(15):R649-50. doi: 10.1016/j.cub.2013.06.026.
Lampreys, together with hagfishes, are the only extant representatives of jawless vertebrates and thus of prime interest for the study of vertebrate evolution [1]. Most lamprey genera occur in two forms with divergent life histories: a parasitic, anadromous and a non-parasitic, freshwater resident form [2-8]. The taxonomic status of such 'paired species' is disputed, however. While indistinguishable at larval stages, but clearly distinct as adults, they cannot be differentiated with available genetic data [6,7], which has fuelled speculations that the two forms may in fact represent products of phenotypic plasticity within a single species. Here, we use restriction site-associated DNA sequencing (RADseq) to examine the genetic population structure of sympatric European river (Lampetra fluviatilis L., 1758) and brook (Lampetra planeri Bloch, 1784) lampreys. We find strong genetic differentiation and identify numerous fixed and diagnostic single nucleotide polymorphisms (SNPs) between the two species, 12 of which can be unequivocally assigned to specific genes.
七鳃鳗，与盲鳗一起，是现存的无颚脊椎动物的唯一代表，因此是研究脊椎动物进化的主要对象[1]。大多数七鳃鳗属在两种形式中出现，具有不同的生活史：一种是寄生的洄游性和非寄生的淡水居留形式[2-8]。然而，这种“配对物种”的分类地位存在争议。虽然在幼虫阶段无法区分，但成虫阶段明显不同，但是无法用现有的遗传数据将它们区分开来[6,7]，这引发了这样一种猜测，即这两种形式实际上可能代表单一物种内表型可塑性的产物。在这里，我们使用限制位点相关 DNA 测序（RADseq）来研究欧洲河流（Lampetra fluviatilis L.，1758）和溪流（Lampetra planeri Bloch，1784）七鳃鳗的遗传种群结构。我们发现存在强烈的遗传分化，并在两个物种之间鉴定出许多固定和诊断性单核苷酸多态性（SNP），其中 12 个 SNP 可以明确分配给特定的基因。
