Université Paris Est Créteil, Université Pierre et Marie Curie, CNRS, INRA, IRD, Université Paris-Diderot, Institut d'écologie et des sciences de l'environnement de Paris (iEES-Paris), Créteil, France.
Department of Biology, University of Iowa, Iowa City, IA 52242-1324, USA.
Mol Phylogenet Evol. 2018 Jul;124:60-70. doi: 10.1016/j.ympev.2018.02.021. Epub 2018 Feb 28.
Pontoscolex corethrurus is the most widespread earthworm species in tropical and sub-tropical zones and one of the most studied in soil science. Although, ecological interactions of P. corethrurus with its environment are well documented, the taxonomic status of the species remains unclear. In this study, we investigated phylogenetic relationships within the genus Pontoscolex, in particular focusing on morphologically indistinguishable (i.e., cryptic) lineages. A total of 792 specimens collected from 25 different countries and islands all over the world were analyzed using two mitochondrial (COI and 16S rDNA) and two nuclear (internal transcribed spacers 2 and 28S rDNA) markers, and a total of 11 morphological characters both internal and external were investigated in all genetically characterized lineages. A large-scale multilocus sequence data matrix was also obtained for Pontoscolex spp. specimens using the Anchored Hybrid Enrichment (AHE) method. Multilocus phylogenetic and phylogenomic analyses, combined with species delimitation methods; including single locus (mPTP, ABGD) and multilocus (BPP) approaches, revealed congruent results. Four cryptic species were supported within the P. corethrurus species complex, and four potentially new species within the genus Pontoscolex. One widespread lineage (L1), within P. corethrurus complex was observed in the current population of Fritz Müller's garden where P. corethrurus was first described in 1856. Cryptic lineages were observed in sympatry at several localities. This, in combination with observed heteroplasmy in COI gene in one population raises an important question of reproductive isolation between these species.
蛭蚓科 Pontoscolex 是热带和亚热带地区分布最广泛的蚯蚓物种之一，也是土壤科学中研究最多的物种之一。尽管 P. corethrurus 与环境的生态相互作用已有详细记录，但该物种的分类地位仍不清楚。在本研究中，我们调查了 Pontoscolex 属内的系统发育关系，特别是关注形态上不可区分（即隐蔽）的谱系。总共分析了来自 25 个不同国家和岛屿的 792 个标本，使用了两个线粒体（COI 和 16S rDNA）和两个核（内部转录间隔区 2 和 28S rDNA）标记，以及总共 11 个内部和外部形态特征在所有遗传特征谱系中进行了研究。还使用 Anchored Hybrid Enrichment (AHE) 方法为 Pontoscolex spp. 标本获得了大规模的多基因座序列数据集。多基因座系统发育和系统基因组分析，结合物种界定方法；包括单基因座（mPTP、ABGD）和多基因座（BPP）方法，揭示了一致的结果。在 P. corethrurus 种复合体中支持 4 个隐蔽种，在 Pontoscolex 属中支持 4 个潜在新种。在弗里茨·穆勒花园（Fritz Müller's garden）的当前种群中观察到一个广泛分布的谱系（L1），该花园是 1856 年首次描述 P. corethrurus 的地方。在几个地方观察到隐蔽谱系共生。这与一个种群中 COI 基因观察到的异质现象相结合，提出了这些物种之间生殖隔离的重要问题。
