Morii Kiyohito, Sakamoto Yoshiko, Watari Yuya, Iijima Hayato, Doi Kandai, Morishima Kaori, Komine Hirotaka, Okabe Kimiko, Goka Koichi
National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, 305-8506, Ibaraki, Japan.
Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba, 305-8687, Ibaraki, Japan.
Exp Appl Acarol. 2024 Dec 17;94(1):8. doi: 10.1007/s10493-024-00971-y.
The Asian longhorned tick, Haemaphysalis longicornis Neumann (Ixodida: Ixodidae), is widely distributed across temperate East Asia, including Japan, and carries a variety of zoonotic diseases. The species includes bisexual and parthenogenetic lineages. Various aspects of these two lineages, such as their abundance ratio, genetic relationship, and population structure, remain unknown in island environments such as Japan that are isolated from the mainland. Therefore, in this study, 235 individuals were collected across 15 prefectures, and their mtDNA was analyzed to better understand the genetic population structure of this species in Japan. Haplotype analysis of the 631 bp cox1 region revealed the presence of 38 haplotypes, which showed for the first time that a large diversity of haplotypes is present in Japan. In addition, the calculated haplotype diversity was 0.889-equivalent to that reported in the study that examined haplotypes across a larger region in China. This indicates that Japan is a hotspot of genetic diversity of this species. The haplotype network of this species was divided into two major clades, but there were no clear geographical boundaries in the distributions of the haplotypes. However, a qualitative cline was observed in the distribution of sexual lineage, with the parthenogenetic lineage being more prevalent in northeastern Japan and the bisexual lineage being more prevalent in southwestern Japan. Future analysis combining the results of this paper with information from nuclear DNA and large-scale mtDNA analyses would facilitate a more detailed understanding of the population structure and historical distributions of the Asian longhorned tick.
亚洲长角血蜱，长角血蜱（硬蜱目：硬蜱科），广泛分布于包括日本在内的东亚温带地区，并携带多种人畜共患病。该物种包括两性生殖和孤雌生殖谱系。在与大陆隔离的日本等岛屿环境中，这两个谱系的各个方面，如它们的丰度比、遗传关系和种群结构，仍然未知。因此，在本研究中，我们在15个县采集了235个个体，并对其线粒体DNA进行了分析，以更好地了解该物种在日本的遗传种群结构。对631bp的细胞色素c氧化酶亚基1（cox1）区域的单倍型分析揭示了38种单倍型的存在，这首次表明日本存在大量的单倍型多样性。此外，计算得出的单倍型多样性为0.889，与在中国更大区域进行单倍型研究报告的结果相当。这表明日本是该物种遗传多样性的一个热点地区。该物种的单倍型网络分为两个主要分支，但单倍型的分布没有明显的地理界限。然而，在性谱系的分布中观察到了一个定性的渐变群，孤雌生殖谱系在日本东北部更为普遍，而两性生殖谱系在日本西南部更为普遍。未来结合本文结果与核DNA信息以及大规模线粒体DNA分析结果的分析，将有助于更详细地了解亚洲长角血蜱的种群结构和历史分布。
