Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan.
Parasit Vectors. 2019 Aug 5;12(1):389. doi: 10.1186/s13071-019-3630-5.
Two transmission patterns of Sarcoptes scabiei in host mammal communities have been reported based on microsatellite-level genetic studies in the last two decades. While one involves restrictions among different host taxa, the other is associated with predator-prey interactions between different host taxa. In contrast to these observations, the present study reports a possible irregular case of transmission of S. scabiei between herbivorous Japanese serow and omnivorous Caniformia mammals in Japan, though under very weak predator-prey relationships.
DNA from 93 Sarcoptes mites isolated from omnivorous Caniformia (such as the domestic dog, raccoon dog, raccoon and Japanese marten), omnivorous Cetartiodactyla (wild boar) and herbivorous Cetartiodactyla (Japanese serow) in Japan were analyzed by amplifying nine microsatellite markers. Principal components analyses (PCA), Bayesian clustering analyses using STRUCTURE software, and phylogenetic analyses by constructing a NeighborNet network were applied to determine the genetic relationships among mites associated with host populations.
In all the analyses, the genetic differentiation of Sarcoptes mites from wild boars and Japanese serows was observed. Conversely, considerably close genetic relationships were detected between Caniformia-derived and Japanese serow-derived mites. Because the predator-prey interactions between the omnivorous Caniformia and herbivorous Japanese serow are quite limited and epidemiological history shows at least a 10-year lag between the emergence of sarcoptic mange in Japanese serow and that in Caniformia, the transmission of S. scabiei from Caniformia to Japanese serow is highly suspected.
The close genetic relationships among mites beyond Host-taxon relationships and without obvious predator-prey interactions in Caniformia and Japanese serow deviate from previously reported S. scabiei transmission patterns. This type of cryptic relationship of S. scabiei populations may exist in local mammalian communities worldwide and become a risk factor for the conservation of the remnant and fragmented populations of wild mammals.
在过去的二十年中，基于微卫星水平的遗传研究，已经报道了宿主哺乳动物群落中疥螨的两种传播模式。一种涉及不同宿主分类群之间的限制，另一种与不同宿主分类群之间的捕食者-猎物相互作用有关。与这些观察结果相反，本研究报告了在日本，食草的日本羚鹿和杂食性的 Caniformia 哺乳动物之间传播疥螨的一种可能不规则情况，尽管它们之间的捕食者-猎物关系非常微弱。
从日本的杂食性 Caniformia（如家犬、貉、浣熊和日本貂）、杂食性 Cetartiodactyla（野猪）和食草性 Cetartiodactyla（日本羚鹿）中分离出的 93 只疥螨的 DNA，通过扩增 9 个微卫星标记进行分析。应用主成分分析（PCA）、STRUCTURE 软件的贝叶斯聚类分析以及构建 NeighborNet 网络的系统发育分析来确定与宿主种群相关的螨的遗传关系。
在所有分析中，都观察到了来自野猪和日本羚鹿的疥螨的遗传分化。相反，Caniformia 衍生的和日本羚鹿衍生的螨之间存在相当密切的遗传关系。由于杂食性 Caniformia 和食草性日本羚鹿之间的捕食者-猎物相互作用非常有限，而且流行病学史表明，在日本羚鹿和 Caniformia 中出现疥螨病之间至少有 10 年的滞后，因此高度怀疑 Caniformia 向日本羚鹿传播了 S. scabiei。
Caniformia 和日本羚鹿中螨之间超越宿主分类群关系且没有明显的捕食者-猎物相互作用的密切遗传关系偏离了先前报道的 S. scabiei 传播模式。这种疥螨种群的隐匿关系可能存在于全球各地的当地哺乳动物群落中，并成为保护野生哺乳动物残余和碎片化种群的一个风险因素。
