Nazarizadeh Masoud, Martinů Jana, Nováková Milena, Stanko Michal, Štefka Jan
Institute of Parasitology, Biology Centre CAS, Branišovská 31, 370 05, České Budějovice, Czech Republic.
Faculty of Science, University of South Bohemia, Branišovska 1760, 370 05, České Budějovice, Czech Republic.
BMC Zool. 2022 Mar 24;7(1):15. doi: 10.1186/s40850-022-00115-y.
Laelaps agilis C.L. Koch, 1836 is one the most abundant and widespread parasitic mite species in the Western Palearctic. It is a permanent ectoparasite associated with the Apodemus genus, which transmits Hepatozoon species via the host's blood. Phylogenetic relationships, genealogy and host specificity of the mite are uncertain in the Western Palearctic. Here, we investigated the population genetic structure of 132 individual mites across Europe from their Apodemus and Clethrionomys hosts. Phylogenetic relationships and genetic variation of the populations were analyzed using cytochrome c oxidase subunit I (COI) gene sequences.
We recovered three main mtDNA lineages within L. agilis in the Western Palearctic, which differentiated between 1.02 and 1.79 million years ago during the Pleistocene period: (i) Lineage A, including structured populations from Western Europe and the Czech Republic, (ii) Lineage B, which included only a few individuals from Greece and the Czech Republic; and (iii) Lineage C, which comprised admixed populations from Western and Eastern Europe. Contrary to their population genetic differentiation, the lineages did not show signs of specificity to different hosts. Finally, we confirmed that the sympatric congener L. clethrionomydis is represented by a separated monophyletic lineage.
Differences in the depth of population structure between L. agilis Lineages A and C, corroborated by the neutrality tests and demographic history analyses, suggested a stable population size in the structured Lineage A and a rapid range expansion for the geographically admixed Lineage C. We hypothesized that the two lineages were associated with hosts experiencing different glaciation histories. The lack of host specificity in L. agilis lineages was in contrast to the co-occurring highly host-specific lineages of Polyplax serrata lice, sharing Apodemus hosts. The incongruence was attributed to the differences in mobility between the parasites, allowing mites to switch hosts more often.
敏捷厉螨（Laelaps agilis C.L. Koch，1836）是西古北区最常见且分布广泛的寄生螨物种之一。它是与姬鼠属相关的永久性体外寄生虫，通过宿主血液传播肝簇虫属物种。在西古北区，该螨的系统发育关系、谱系及宿主特异性尚不确定。在此，我们研究了来自欧洲各地姬鼠属和棕背䶄属宿主的132只个体螨的种群遗传结构。使用细胞色素c氧化酶亚基I（COI）基因序列分析了种群的系统发育关系和遗传变异。
我们在西古北区的敏捷厉螨中发现了三个主要的线粒体DNA谱系，它们在更新世期间距今102万至179万年前分化：（i）谱系A，包括来自西欧和捷克共和国的结构化种群；（ii）谱系B，仅包括来自希腊和捷克共和国的少数个体；（iii）谱系C，由来自西欧和东欧的混合种群组成。与它们的种群遗传分化相反，这些谱系没有表现出对不同宿主的特异性迹象。最后，我们证实同域近缘种克氏厉螨（L. clethrionomydis）由一个独立的单系谱系代表。
中性检验和种群历史分析证实，敏捷厉螨谱系A和C的种群结构深度存在差异，这表明结构化的谱系A种群规模稳定，而地理上混合的谱系C经历了快速的范围扩张。我们推测这两个谱系与经历不同冰川历史的宿主有关。敏捷厉螨谱系缺乏宿主特异性，这与共现的高度宿主特异性的锯形多板虱谱系形成对比，它们共享姬鼠属宿主。这种不一致归因于寄生虫之间移动性的差异，使得螨更频繁地更换宿主。
