Department of Environmental Biology, Sapienza University of Rome, Rome, Italy.
Department of Veterinary Medicine, University of Bari, 70010, Valenzano, Bari, Italy.
Sci Rep. 2019 Feb 6;9(1):1460. doi: 10.1038/s41598-018-38001-8.
Paternal leakage of mitochondrial DNA (mtDNA) and heteroplasmy have been recently described in several animal species. In arthropods, by searching in the Scopus database, we found only 23 documented cases of paternal leakage. Therefore, although arthropods represent a large fraction of animal biodiversity, this phenomenon has been investigated only in a paucity of species in this phylum, thus preventing a reliable estimate of its frequency. Here, we investigated the occurrence of paternal leakage and mtDNA heteroplasmy in ticks belonging to one of the most significant tick species complexes, the so-called Rhipicephalus sanguineus sensu lato. By developing a multiplex allele-specific PCR assay targeting a fragment of the 12S rRNA ribosomal region of the mtDNA, we showed the occurrence of paternal leakage and mtDNA heteroplasmy in R. sanguineus s.l. ticks originated from experimental crosses, as well as in individuals collected from the field. Our results add a new evidence of paternal leakage in arthropods and document for the first time this phenomenon in ticks. Furthermore, they suggest the importance of using allele-specific assays when searching for paternal leakage and/or heteroplasmy, as standard sequencing methods may fail to detect the rare mtDNA molecules.
父系线粒体 DNA（mtDNA）渗漏和异质性最近在几个动物物种中被描述。通过在 Scopus 数据库中搜索，我们在节肢动物中仅发现了 23 例有文献记录的父系渗漏案例。因此，尽管节肢动物代表了动物生物多样性的很大一部分，但这种现象仅在该门的少数物种中进行了研究，从而无法可靠估计其频率。在这里，我们研究了属于最具重要意义的蜱种复合体之一的蜱中父系渗漏和 mtDNA 异质性的发生情况，即所谓的 Rhipicephalus sanguineus sensu lato。通过开发一种针对 mtDNA 12S rRNA 核糖体区片段的多重等位基因特异性 PCR 检测方法，我们证明了源自实验杂交的 R. sanguineus s.l.蜱以及从野外采集的个体中存在父系渗漏和 mtDNA 异质性。我们的结果为节肢动物中的父系渗漏增加了新的证据，并首次记录了这种现象在蜱中的存在。此外，它们表明在寻找父系渗漏和/或异质性时使用等位基因特异性检测方法的重要性，因为标准测序方法可能无法检测到罕见的 mtDNA 分子。
