Identification of different toxoplasma virulence genes in the east and west of Eurasia and the history of their spread

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K19320
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Veterinary medical science, Animal science, and related fields
• Research Institution: Gifu University
• Principal Investigator: Takashima Yasuhiro 岐阜大学, 応用生物科学部, 准教授 (20333552)
• Co-Investigator(Kenkyū-buntansha): 永宗 喜三郎 国立感染症研究所, 寄生動物部, 室長 (90314418) ; 海野 明広 愛知県衛生研究所, 生物学部医動物研究室, 主任 (50628592)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: トキソプラズマ / 病原性 / ユーラシア大陸

Outline of Final Research Achievements

Among the Toxoplasma strains isolated in Japan, we analyzed the genomic information of one strain whose expected and actual virulence differ greatly, and we analyzed it at any locus known to be involved in virulence. , No mutation was found between any of the previously reported sequences. On the other hand, the copy numbers of some genes were different. These results suggest that duplication or deletion of multiple copied genes occurs in Toxoplasma strains in East Eurasia. This may be involved in atypical pathogenicity. He also revealed that European and North American stocks, which are expanding their distribution throughout the world, are currently spreading to at least Russia and the Republic of Tatarstan.

Free Research Field

獣医学

Academic Significance and Societal Importance of the Research Achievements

トキソプラズマの遺伝子タイピングに基づく疫学的研究は世界中で行われている。しかし現状では申請者が見出したような、東部ユーラシアに特有の「高病原性Type II, Type III株」を機械的に低病原性・非病原性と誤判定している可能性が高い。これは本原虫感染症のリスク評価を誤らせる重大な懸念事項である。本研究の成果により、東部ユーラシア株の遺伝子構造が明らかになり、遺伝子タイピングによる病原性評価にか道を開いた。