Mechanisms underlying unusual DNA synthesis during the moss reprogramming

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K06302
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: National Institute for Basic Biology
• Principal Investigator: Ishikawa Masaki 基礎生物学研究所, 生物進化研究部門, 助教 (00586894)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: ヒメツリガネゴケ / 幹細胞化 / 細胞周期 / DNA合成

Outline of Final Research Achievements

In the moss Physcomitrium patens, upon wounding, leaf cells reactivate the cell cycle and change into stem cells. In this process, the cell cycle-dependent DNA synthesis (unusual DNA synthesis), which is different from the usual nuclear genome DNA replication, is required for the cell fate change. In this study, we aimed to elucidate the regulatory mechanism of the unusual DNA synthesis during stem cell formation in order to understand the relationship between the cell cycle reentry/progression and the cell fate change. Our results suggest that genomic DNA damage occurs during stem cell formation, which leads to the activation of the DNA repair system related to the novel DNA synthesis. We also found that the DNA repair system, which is activated by genomic DNA damage, is involved in stem cell formation. These results suggest that the DNA repair system may be involved in the demethylation of genomic DNA and these processes may be the novel DNA synthesis during stem cell formation.

Free Research Field

植物幹細胞生物学

Academic Significance and Societal Importance of the Research Achievements

ヒメツリガネゴケの幹細胞化における細胞周期制御下にある新奇DNA合成が細胞運命転換を誘導するというアイデアは、「細胞周期における各ステージの役割は、ただ単に細胞周期を動かすためだけなのか」、という細胞周期制御についての根源的な問いに立ち返ることになり、本研究から得られた成果は、動植物の枠を超えた新たな細胞周期研究の展開に繋がる可能性を秘めており、その学術的意義は大きい。