Department of Evolutionary Genetics and Biosystematics, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland.
Department of Zoology and Nature Conservation, Faculty of Biology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland.
Sci Rep. 2024 Oct 14;14(1):23984. doi: 10.1038/s41598-024-75335-y.
Myrmecophilus acervorum, previously considered a parthenogenetic species widely-distributed in Europe, has been observed to have both sexes in populations inhabiting the central part of the distribution range. Specimens from those heterosexual populations have been found being infected with Wolbachia. New mitochondrial data (COI and 16S markers) revealed the well-supported differentiation of M. acervorum populations inhabiting western Polesie (Poland) and southern Europe. In turn, analyses of EF1α marker support the hypothesis on the unfinished lineage sorting at the nuclear DNA level. Interestingly, we found that parthenogenetic populations inhabiting western Polesie are infected with Wolbachia belonging to supergroup A, while endosymbionts occurring in sexual populations of M. acervorum observed in Romania belong to supergroup B. Furthermore, new and potentially diagnostic characteristics in the external structures of the eyes of M. acervorum were identified. The surface of ommatidia in specimens occurring in southern Europe was smooth. In contrast, the ommatidia surface of individuals collected in Poland was visibly sculptured. To sum up, the significant genetic variability found in the present case, and the differentiating morphological character, are almost certainly effects of cryptic species being present within M. acervorum. This is indicative of ongoing speciation within the populations of this insect, and of simultaneous unfinished lineage sorting at the nuclear DNA level.
棘蚁毛蚁，曾被认为是一种在欧洲广泛分布的孤雌生殖物种，在分布范围中心的种群中观察到同时具有两性。来自这些有性种群的标本被发现感染了沃尔巴克氏体。新的线粒体数据（COI 和 16S 标记）揭示了栖息在波兰西部波列西耶（Poland）和南欧的棘蚁毛蚁种群的良好分化。反过来，EF1α 标记的分析支持了核 DNA 水平上未完成的谱系分类假说。有趣的是，我们发现栖息在波兰西部的孤雌生殖种群感染了属于超级群 A 的沃尔巴克氏体，而在罗马尼亚观察到的棘蚁毛蚁有性种群中的内共生体则属于超级群 B。此外，还发现了棘蚁毛蚁眼睛外部结构的新的潜在诊断特征。在欧洲南部出现的标本的小眼表面是光滑的。相比之下，在波兰采集的个体的小眼表面明显具有雕刻纹理。总之，在本案例中发现的显著遗传变异性和分化的形态特征，几乎可以肯定是棘蚁毛蚁中存在隐种的结果。这表明该昆虫种群正在发生物种形成，同时核 DNA 水平上也存在未完成的谱系分类。
