Epigenetic features of mammalian mitochondrial DNA

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07504
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Genetics/Chromosome dynamics
• Research Institution: Kyushu University
• Principal Investigator: Yasukawa Takehiro 九州大学, 医学研究院, 助教 (90646720)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: ミトコンドリアDNA

Outline of Final Research Achievements

While cytosine methylation in nuclear DNA in human and other mammals is known to play important roles, whether mitochondrial DNA, which is contained in mitochondria, receives the modification or not remains controversial. It could have profound impact on gene expression and maintenance of mitochondrial DNA, and abnormalities in mitochondrial DNA methylation might well be a cause of disease with mitochondrial dysfunction. Investigation of mitochondrial DNA methylation is thus of pivotal importance. In this research project, thorough analysis of mtDNA from mouse tissues and cultured embryonic stem cells was conducted using three methods. Data from the analysis led to a proposal that the 5-methylcytosine is not present at any specific position(s) in mitochondrial DNA and levels of the methylated cytosine are fairly low, provided the modification occurs. We therefore propose it is unlikely that 5mC plays a universal role in the gene expression or metabolism of mitochondrial DNA.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

近年、mtDNAはメチル化されているという報告が相次いでいたが、これらの中には互いに異なる内容の主張のものがみられたりと、非常に混迷した状況が続いていた。mtDNAがメチル化修飾を受けるか否かはmtDNAの適切な維持や遺伝子発現を考える上で重要な課題であり、その異常が疾患に関連する可能性も秘めている。今回、メチル化修飾についてmtDNAの真の姿の一端を明らかにしたことで、今後のmtDNA基礎研究・医学研究に有益な情報を提供できたことは本研究の意義といえる。