Comparative population genetic structure of two ixodid tick species (Acari:Ixodidae) (Ixodes ovatus and Haemaphysalis flava) in Niigata prefecture, Japan

Maria Angenica F Regilme; Megumi Sato; Tsutomu Tamura; Reiko Arai; Marcello Otake Sato; Sumire Ikeda; Maribet Gamboa; Michael T Monaghan; Kozo Watanabe

doi:10.1016/j.meegid.2021.104999

Comparative population genetic structure of two ixodid tick species (Acari:Ixodidae) (Ixodes ovatus and Haemaphysalis flava) in Niigata prefecture, Japan

Infect Genet Evol. 2021 Oct:94:104999. doi: 10.1016/j.meegid.2021.104999. Epub 2021 Jul 10.

Authors

Maria Angenica F Regilme¹, Megumi Sato², Tsutomu Tamura³, Reiko Arai³, Marcello Otake Sato⁴, Sumire Ikeda⁵, Maribet Gamboa¹, Michael T Monaghan⁶, Kozo Watanabe⁷

Affiliations

¹ Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577, Japan; Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime 790-8577, Japan.
² Graduate School of Health Sciences, Niigata University, Niigata 951-8518, Japan.
³ Niigata Prefectural Institute of Public Health and Environmental Sciences, Niigata 950-2144, Japan.
⁴ Department of Tropical Medicine and Parasitology, Dokkyo Medical University, 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan.
⁵ Research Laboratories, Research and Development Headquarters, Earth Corporation, Hyogo 678-0192, Japan.
⁶ Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin 12587, Germany; Institut für Biologie, Freie Universität Berlin, Berlin 14195, Germany.
⁷ Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577, Japan; Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime 790-8577, Japan. Electronic address: watanabe.kozo.mj@ehime-u.ac.jp.

PMID: 34256167
DOI: 10.1016/j.meegid.2021.104999

Abstract

Ixodid ticks (Acari:Ixodidae) are essential vectors of tick-borne diseases in Japan. In this study, we characterized the population genetic structure and inferred genetic divergence in two widespread and abundant ixodid species, Ixodes ovatus and Haemaphysalis flava. Our hypothesis was that genetic divergence would be high in I. ovatus because of the low mobility of their small rodent hosts of immature I. ovatus would limit their gene flow compared to more mobile avian hosts of immature H. flava. We collected 320 adult I. ovatus from 29 locations and 223 adult H. flava from 17 locations across Niigata Prefecture, Japan, and investigated their genetic structure using DNA sequences from fragments of two mitochondrial gene regions, cox1 and the 16S rRNA gene. For I. ovatus, pairwise F_ST and analysis of molecular variance (AMOVA) analyses of cox1 and 16S sequences indicated significant genetic variation among populations, whereas both markers showed non-significant genetic variation among locations for H. flava. A cox1 gene tree and haplotype network revealed three genetic groups of I. ovatus. One of these groups consisted of haplotypes distributed at lower altitudes (251-471 m.a.s.l.). The cox1 sequences of I. ovatus from Japan clustered separately from I. ovatus sequences reported from China, suggesting the potential for cryptic species in Japan. Our results support our hypothesis and suggest that the host preference of ticks at the immature stage may influence the genetic structure of the ticks. This information may be important for understanding the tick-host interactions in the field to better understand the tick-borne disease transmission and in designing an effective tick control program.

Keywords: Altitude; Genetic divergence; Mantel test; Species complex; Tick dispersal.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Arthropod Proteins / genetics*
Electron Transport Complex IV / genetics*
Genetic Variation*
Ixodidae / genetics*
Japan
RNA, Ribosomal, 16S / genetics*
Species Specificity

Substances

Arthropod Proteins
RNA, Ribosomal, 16S
Electron Transport Complex IV