Szudarek Natalia, Kanarek Gerard, Dabert Jacek
Acta Parasitol. 2017 Mar 1;62(1):76-89. doi: 10.1515/ap-2017-0009.
The astigmatid family Hypoderatidae includes over 80 mite species exhibiting peculiar life cycle. Deutonymphs are parasitic instars inhabiting subcutaneous or visceral tissues of birds and rodents, while all other instars are nidicolous forms. In this study we investigated genetic diversity of deutonymphs of two hypoderatid species, Neottialges evansi and Phalacrodectes gaudi, collected from 16 individuals of the great cormorant Phalacrocorax carbo in SW Poland during host post-breeding dispersal. The initial alternative hypotheses were: (1) populations of deutonymphs in both mite species found in tissues of particular bird individuals form genetically distinct populations, (2) mites are panmictic among hosts. The topologies of NJ phylogenetic trees and median-joining haplotype networks reconstructed for COI haplotypes revealed lack of hostdependent genetic structure in populations of N. evansi and P. gaudi. Furthermore, high haplotype diversity (Hd) and low nucleotide diversity (Pi) prove high genetic differentiation of both mite species. We concluded, that unlimited dispersal of mites among cormorant specimens could be explained by host specific breeding behavior: free mating between cormorants originating from different European populations and low contribution of reunited pairs in breeding colonies in subsequent breeding seasons, reuse of the same nest material by different members of the colony, and host behavior called prospecting.
粉螨科Hypoderatidae包括80多种具有独特生命周期的螨类物种。若螨是寄生于鸟类和啮齿动物皮下或内脏组织的龄期，而其他所有龄期均为巢栖型。在本研究中，我们调查了从波兰西南部的16只鸬鹚（Phalacrocorax carbo）个体在宿主繁殖后扩散期间采集的两种Hypoderatidae螨类物种——埃氏新纳螨（Neottialges evansi）和高氏甲螨（Phalacrodectes gaudi）的若螨的遗传多样性。最初的备择假设是：（1）在特定鸟类个体组织中发现的两种螨类物种的若螨种群形成遗传上不同的种群，（2）螨类在宿主之间是随机交配的。为COI单倍型重建的NJ系统发育树和中介连接单倍型网络的拓扑结构显示，埃氏新纳螨和高氏甲螨的种群中缺乏宿主依赖性遗传结构。此外，高单倍型多样性（Hd）和低核苷酸多样性（Pi）证明了这两种螨类物种的高度遗传分化。我们得出结论，螨类在鸬鹚个体之间的无限制扩散可以通过宿主特定的繁殖行为来解释：来自不同欧洲种群的鸬鹚之间自由交配，以及在随后繁殖季节中重新团聚的配对在繁殖群体中的贡献较低，群体中的不同成员重复使用相同的巢材，以及宿主的“探矿”行为。
