Regulation of nuclear fusion by the LINC complex during sexual reproduction of Arabidopsis

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06704
• 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: Niigata University
• Principal Investigator: Nishikawa Shuh-ichi 新潟大学, 自然科学系, 教授 (10252222)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 核膜融合 / 雌性配偶体 / 重複受精 / シロイヌナズナ / 核膜タンパク質

Outline of Final Research Achievements

The LINC complex is a protein complex formed by the SUN protein in the inner nuclear membrane and the KASH protein in the outer nuclear membrane. The LINC complex functions in various processes including nuclear migration and positioning. In this study, we improved our female gametophyte-specific gene induction system. Using the improved system, we analyzed the roles of the LINC complex in nuclear fusion (polar nuclear fusion and sperm nuclear fusion) during sexual reproduction in Arabidopsis thaliana. Our results suggested that the SUN protein is required for polar nuclear fusion but not for sperm nuclear fusion. We identified a KASH protein expressed in the female gametophyte and analyzed its functions in nuclear fusion. We also analyzed the functional domains GEX1, a nuclear membrane protein required for nuclear membrane fusion.

Free Research Field

植物細胞生物学

Academic Significance and Societal Importance of the Research Achievements

本研究で作製した改良型の雌性配偶体特異的な遺伝子発現誘導系は、雌性配偶体形成初期過程からの遺伝子機能の解析を含め、利用可能な範囲が広がったといえる。また、極核融合と精核融合のメカニズムの違いを示唆する結果は、2種類の核融合を区別する機構の探索への展開が期待できる。本研究によって特定したKASHタンパク質やGEX1を足がかりとした解析によって、有性生殖過程の核膜融合の分子機構の理解が進むと考えられる。