Analyses of the molecular mechanism involved in the selective degradation of paternal mitochondrial DNA in maternal inheritance

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K06313
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44040:Morphology and anatomical structure-related
• Research Institution: Nagoya University
• Principal Investigator: Sasaki Narie 名古屋大学, 理学研究科, 准教授 (20359699)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 母性遺伝 / ミトコンドリア / 父方選択的分解 / ヌクレアーゼ

Outline of Final Research Achievements

Physarum polycephalum has large mitochondrial nucleoids, which are mitochondrial DNA (mtDNA)-protein complexes. In this study, we developed a semi-in vitro assay to detect DNase activity by microscopic observation of the digestion of mtDNA in isolated mitochondria from P. polycephalum and the DNase involved in maternal inheritance was characterized. When the mitochondria isolated from zygotes were used, the digestion of mtDNA in isolated mitochondria was specifically observed in the presence of Mg2+ and maximum activity was detected at pH 7.7. During the digestion of mtDNA, mitochondrial membrane integrity was maintained in vivo. Furthermore, we also developed a method to distinguish uniparental mitochondria in zygotes of P. polycephalum by chemical staining. Our results showed that the proliferation of maternal mitochondria rapidly occurred after the initiation of digestion of paternal mtDNA.

Free Research Field

分子細胞生物学

Academic Significance and Societal Importance of the Research Achievements

母性遺伝のメカニズムは生物によって異なっており、多様性がみられる。有性生殖は、同形配偶子生殖から異形配偶子生殖、そして卵生生殖へと進化してきたと考えられる。同形配偶子である真正粘菌におけるmtDNAの母性遺伝のメカニズムを解明することは、母性遺伝の進化を理解する上で非常に重要であり、本研究で得られた知見は、真正粘菌の母性遺伝における父方mtDNAの選択的分解に関与する分子メカニズムを解明するために役立つことが期待される。