UMEMIYA-SHIRAFUJI Rika Associate Professor

Field

Tick Biology, Veterinary Parasitology, Veterinary Entomology

Keyword

Tick, Vector, Babesia, Theileria, Nutrient metabolism, Starvation, Autophagy, Oogenesis, Vitellogenin, Target of rapamycin (TOR)

Instructable research topic for doctoral thesis

  • マダニの栄養代謝(飢餓・飽血)に関する研究
  • マダニ卵形成の分子機構に関する研究
  • マダニとマダニ媒介性原虫の相互作用に関する研究

Message

吸血性節足動物であるマダニは、人獣にとって脅威となる様々な病原体を媒介します。私は、マダニの生物学、すなわち「マダニそのもの」をよく理解することにより、マダニとマダニ媒介性病原体の対策法の開発研究に繋がる知見を得たいと考えています。
原虫病研究センターにおいては、国内最重要マダニ種であるフタトゲチマダニを初め、現在数種のマダニを飼育管理しています。これらのマダニを研究材料として、①遺伝子クローニング、②遺伝子発現解析、③組換えタンパク質作製、④標的遺伝子発現抑制(ノックダウン)マダニの作出、⑤組織培養、⑥組織切片作製、⑦原虫感染マダニの作出といった様々な実験手法により、各研究テーマに取り組んでいます。また、マダニを1匹ずつ丁寧に解剖して内部臓器を観察・摘出するという、貴重な作業を経験することができます。顕微鏡下で観察すると意外と美しい…かも?
どのようにして吸血し、栄養分を獲得し、生命を維持し、子孫を残し、時に病原体を媒介するのか、未知の部分はまだまだ残っています。新しい実験手法や装置を試行錯誤したり、吸血が終わるのをひたすら待ったり、地味なことが多いですが、卒業研究のテーマにマダニを選んでみてはいかがでしょうか。

Academic degree Doctor of Veterinary Sciences (PhD)
License Clinical laboratory technician
Self introduction

I was interested in parasitology when I was a high school student. As an undergraduate, I didn't have the opportunity to engage in parasitology research. But I pursued research on Cryptosporidium parvum, a protozoan parasite, in my master's course. After that, I began tick research in my doctoral course. Although ticks are harmful pests for animals and humans, they are very interesting organisms when reconsidered from various angles.

Room addressNational Research Center for Protozoan Diseases
Mail address umemiya atmark obihiro.ac.jp

Belongs

National Research Center for Protozoan Diseases/Department of Infection and Immunity/Research Unit for Functional GenomicsResearch Center for Global Agromedicine/Department of Veterinary Medicine

Introduction

  • Ticks are obligatory hematophagous arthropods and are known to be important vectors for various pathogens for vertebrates, such as Babesia and Theileria parasites. Our laboratory researches the molecular mechanisms underlying nutrient metabolism in unfed or fed ticks and tick oogenesis. Moreover, using ticks infected with parasites, we are studying the relationship between transmission of parasites and nutrient metabolism of ticks. We aim to contribute to the development of new methods for controlling ticks and tick-borne pathogens.
  • Several species of ticks are constantly maintained as research resources in National Research Center for Protozoan Diseases. In addition to using the tick colonies for the research mentioned above, we're promoting collaborative and commissioned research to test the effects of acaricides, repellents, etc. on ticks. (Refer to the photos “A laboratory colony of Haemaphysalis longicornis.” and “Collection of ticks in the field.”)
A laboratory colony of Haemaphysalis longicornis.
Collection of ticks in the field.

List of current research topics

  • Nutrient metabolism in unfed/fed ticks
  • Oogenesis in ticks
  • Tick-protozoan parasite interactions
Related industries Veterinary medicine, Animal husbandry
Affiliated academic society The Japanese Society of Veterinary Science, Japanese Society of Veterinary Parasitologists, The Acarological Society of Japan, The Japanese Society of Parasitology, Japan Society of Medical Entomology and Zoology
Academic background 2002, Bachelor in Health Sciences (Faculty of Health Sciences, Kyorin University)
2004, Master in Health Sciences (Graduate School of Health Sciences, Kyorin University)
2004, Researcher (National Research Center for Protozoan Diseases (NRCPD), Obihiro University of Agriculture and Veterinary Medicine)
2006-2008, Research Fellow DC1 of the Japan Society for the Promotion of Science (JSPS) (United Graduate School of Veterinary Sciences, Gifu University / NRCPD)
2008, Doctor of Veterinary Sciences (PhD) (United Graduate School of Veterinary Sciences, Gifu University)
2008-2009, Research Fellow PD of JSPS (Faculty of Agriculture, Kagoshima University)
2009-2011, Researcher (Faculty of Agriculture, Kagoshima University)
2011-2012, Research Fellow RPD of JSPS (Faculty of Agriculture, Kagoshima University)
2012-present, Assistant Professor (NRCPD, Obihiro University of Agriculture and Veterinary Medicine)