Differences between two flagella of the green alga Chlamydomonas

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21420
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 44:Biology at cellular to organismal levels, and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Wakabayashi Ken-ichi 東京工業大学, 科学技術創成研究院, 准教授 (80420248)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 鞭毛・繊毛 / ダイニン / クラミドモナス / 緑藻

Outline of Final Research Achievements

This study aimed to clarify the differences between the two flagella of the green alga Chlamydomonas.
The mutant strain of interest beats only one flagellum and is deficient in the outer arm α heavy chain and inner arm subspecies a, c, and d. We considered that the structure between these dyneins might exist asymmetrically in the two flagella. To test this hypothesis, we generated strains deficient in outer arm α heavy chain and one of inner arm a, c, and d. However, all of these beat both of two flagella. Therefore, it is possible that a structure spanning between multiple inner arm dyneins is responsible. Cryo-electron microscopy of the mutant flagella revealed a structure that was lost in only one of the flagella. The protein responsible for this structure is currently being identified.

Free Research Field

細胞生物学

Academic Significance and Societal Importance of the Research Achievements

学術的意義：　まだ片方の鞭毛にしか存在しない構造のタンパク質実体を明らかにできていないが、それができた暁には、進化の過程の大きな謎である「なぜバイコンタ生物が植物に、ユニコンタ生物が動物になったのか」という問いに対する回答に近づくことになる。また、鞭毛運動の調節機構の理解を深化させると期待できる。
社会的意義：　ヒト不動繊毛症候群の発症メカニズムの理解を深化させると期待できる。