Toll receptor signaling mediated epigenetic regulation of blastema formation gene expression in the cricket Gryllus bimaculatus

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06121
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 43050:Genome biology-related
• Research Institution: Okayama University
• Principal Investigator: Bando Tetsuya 岡山大学, 医歯薬学域, 講師 (60423422)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: コオロギ / 再生 / 再生芽細胞 / マクロファージ / 活性酸素

Outline of Final Research Achievements

When the legs of the cricket Gryllus bimaculatus are amputated, the lost parts are regenerated through several molts. Toll and scavenger receptors-expressing plasmatocytes, which are the insect macrophages, promote leg regeneration. However, the details of this process remain poorly understood. In order to gain further insight into this process, we analyzed the function of Duox, which is a NADPH oxidase and produces reactive oxygen species (ROS), during regeneration. Crickets subjected to RNAi-mediated knockdown of Duox exhibited hypertrophy in the regenerating legs and exhibited lethal phenotypes during the nymphal stage. In comparison to control crickets, Duox(RNAi) crickets exhibited increased hemocyte migration and altered epidermal cell proliferation. Additionally, the expression of several ligands of Toll receptors was altered in Duox(RNAi) regenerating legs, suggesting that ROS-mediated regulation of Toll signaling may promote proper leg regeneration in the crickets.

Free Research Field

再生生物学

Academic Significance and Societal Importance of the Research Achievements

多くの再生可能動物において、器官が傷害されると創傷部位でROS産生が高まり、WntシグナルやJNK, ERKなどを介して器官再生を促進することが知られている。コオロギの脚再生では、Duox(RNAi)によりROSを低下させると、再生脚の肥大や幼虫期致死の表現型が示され、血球遊走の増加と細胞増殖の低下が起こっていた。ROSの低下によりToll受容体のリガンドの発現が変化したことから、ROSはTollシグナルの活性化を介して再生を制御すると考えられる。本研究成果より、器官再生におけるTollシグナルの重要性が深まり、免疫と再生の関連を明らかにできた。