Long-term chromatin memory and environmental response

2019 Fiscal Year Final Research Report

• Project Area: Integrative system of autonomous environmental signal recognition and memorization for plant plasticity
• Project/Area Number: 15H05963
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: The University of Tokyo (2016-2019); National Institute of Genetics (2015)
• Principal Investigator: Kakutani Tetsuji 東京大学, 大学院理学系研究科(理学部), 教授 (20332174)
• Project Period (FY): 2015-06-29 – 2020-03-31
• Keywords: ヒストン修飾 / 環境応答 / ヒストンバリアント / DNAメチル化 / 非コードRNA

Outline of Final Research Achievements

Reflecting environmental conditions, ON/OFF states of gene activity are memorized on chromatin in the forms of DNA and histone modifications. These modifications are found in both promoters in internal regions of genes (gene bodies), but role of gene body modifications remains largely unexplored. We examined factors controlling gene body modifications by genetic approaches. Arabidopsis mutations of the histone demethylase gene IBM1 induces accumulation of silent mark H3K9me (methylation of histone H3 lysine 9) in gene bodies as well as developmental abnormalities and defense responses. Genetic screening of suppressor of the ibm1 mutation identified another histone demethylase gene LDL2. LDL2 mediates developmental abnormalities through removal of H3K4me1. A related H3K4 demethylase FLD mediates memory of cold by removing H3K4me1 around transcription terminations sites; and this is co-opted from the global mechanism to control bidirectional transcription.

Free Research Field

植物遺伝学

Academic Significance and Societal Importance of the Research Achievements

植物にとって、病原応答性の記憶や季節応答性の記憶は重要であるが、その機構は大部分が未開拓である。本研究では、良く研究されているプロモーター付近でなく、遺伝子内部の修飾と表現型とのつながりを遺伝学的に調べることにより、転写状態の長期記憶に関わるヒストン脱メチル化因子の役割と制御を明らかにした。