Elucidation of the influence of habitat environment and reproductive phenotype on the population structure of Haemaphysalis longicornis

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K15674
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: Hokkaido University (2020-2021, 2023); Rakuno Gakuen University (2022)
• Principal Investigator: Ohari Yuma 北海道大学, 人獣共通感染症国際共同研究所, 助教 (00847056)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: フタトゲチマダニ / ミトゲノム / ゲノムワイドSNP / 集団構造

Outline of Final Research Achievements

The genetic characteristics based on the mitochondrial genome (mitogenome) and genome-wide SNPs were compared among populations of Haemaphysalis longicornis to elucidate the influence of habitat and reproductive phenotypes. The ticks collected from the natural environment in Japan and Oceania, as well as some laboratory-maintained strains with known reproductive phenotypes, were employed in these analyses. The population separation between Japan and Oceania was clearly demonstrated baed on the population genetic analyses using SNPs. Furthermore, there was no genetic segregation between reproductive phenotypes based on either genetic levels. These findings suggest that the population structure of Haemaphysalis longicornis in Japan is homogeneous among localities.

Free Research Field

寄生虫学

Academic Significance and Societal Importance of the Research Achievements

フタトゲチマダニはウイルスなどの病原体を媒介するため、公衆衛生上の観点からその分布の大きさや移動経路について明らかにする必要がある。本研究ではこれまで実施されていた解析に加えて、より詳細な解析が可能な手法を用いて個体群間の遺伝的関係を調べた。その結果、これまでの手法では識別できなかった個体群を識別できすることができ、日本とオセアニア諸国の間で遺伝的違いが見られた。