The molecular mechanism that locally regulates actin cytoskeleton at compartment boundaries

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K07402
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Developmental biology
• Research Institution: Tohoku University
• Principal Investigator: Umetsu Daiki 東北大学, 生命科学研究科, 助教 (60620474)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 細胞接着 / コンパートメント境界 / 自己組織化 / 細胞の選別 / 細胞間張力 / ショウジョウバエ

Outline of Final Research Achievements

The tissues in our body consist of spatially compartmentalized cells but not just a cell clump. The boundaries between compartments play a pivotal role in animal development by serving as a landmark that is used for tissue patterning. It has long been debated how these boundaries are physically maintained in tissues. In this study, we have found that a Toll receptor family gene Toll-1, whose mammalian homologues are well known for its important role in recognizing surface molecules on pathogens and transducing signals to protect from infections, shows a remarkable differential expression between neighboring compartments in a Drosophila epithelium. By using a cell culture system and cell biological approaches in the live tissue, we showed that Toll-1 acts as an adhesion molecule which maintains the boundaries independent of actin cytoskeleton. These data shows for the first time that the differential adhesion system works in maintaining compartment boundaries in epithelia.

Free Research Field

細胞生物学

Academic Significance and Societal Importance of the Research Achievements

本研究で示した接着分子の発現量の違いによる組織境界の維持メカニズムは1964年にSteinberg博士が提唱した接着差仮説を支持するもので、この仮説が上皮組織で示された初めての例であるという点において学術的価値が高い。Toll遺伝子の哺乳類ホモログはTLR遺伝子群として知られ、免疫細胞による病原体の表面分子の認識に利用されている。それが細胞間の接着分子として生き物の形作りに使われていることを示したことは新規の発見である。今回の研究成果によって、免疫系分子研究の新たな道が切り拓かれた。ショウジョウバエに限らず多くの種や組織で似たような仕組みが働いている可能性がある。