Analysis of maternal inheritance safeguarded by "inhibition of recombination" and "selective replication" in chloroplast DNA.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15812
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Ibaraki University
• Principal Investigator: Kobayashi Yusuke 茨城大学, 理工学研究科(理学野), 助教 (20800692)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 母性遺伝 / クラミドモナス / モノプラズミー / 相同組換え

Outline of Final Research Achievements

Chloroplasts are maternally inherited in many organisms. In　Chlamydomonas　reinhardtii, male chloroplast DNA is selectively degraded during the early stage of zygote maturation. Our study suggests that although there are approximately 80 copies in a chloroplast, limited number of the copies are templated recurrently. This replication system may guarantee maternal inheritance by selectively replicating female chloroplast DNA even when male chloroplast DNA remains in the zygote. We also show that zygote-specific homologous recombination factors are important to stabilize the chloroplast genome to the next generation.

Free Research Field

植物細胞生物学

Academic Significance and Societal Importance of the Research Achievements

葉緑体は光合成を行うことで地球上の多くの生命を支えている。葉緑体DNAに外来遺伝子を導入することで多量の有用タンパク質を葉緑体内に蓄積させ、これをワクチンに利用する研究が進んでいる。また葉緑体が母性遺伝するという特徴から、葉緑体DNAに導入した外来遺伝子は花粉などによって野外に拡散されにくいと考えられている。葉緑体DNAの母性遺伝機構を理解すれば、その知見は有用作物の育種技術に応用できると期待される。