Analysis of molecular interaction and genome evolution in the symbiotic system of green hydra and Chlorella

• Project/Area Number: 25840132
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Evolutionary biology
• Research Institution: Okinawa Institute of Science and Technology Graduate University
• Principal Investigator: Hamada Mayuko 沖縄科学技術大学院大学, マリンゲノミックスユニット, 研究員 (40378584)
• Research Collaborator: BOSCH C. G. Thomas キール大学, 教授
• Project Period (FY): 2013-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2014: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2013: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
• Keywords: 共生 / ゲノム / 進化 / ヒドラ / クロレラ

Outline of Final Research Achievements

To understand common principles of animal-algal symbiosis and their links to evolution at the molecular- and the genome-level, we focused on the mechanisms of interactions between Hydra and Chlorella and the specific features in their genome. We identified candidate genes upregulated only when the specific symbiosis has been established. They included genes involved in nitrogen assimilation and phosphate transport. In addition, the expression of these genes showed clear correlation with photosynthesis of Chlorella. We also performed genome sequencing of the symbiotic Chlorella to understand the genome evolution in the dependent relation. As a result, we found that some genes necessary for nitrate assimilation in plants and their cluster structure have been lost. This indicates that symbiotic Chlorella is dependent on the nitrogen source provided from Hydra and that the nitrate assimilation pathway in symbiotic Chlorella is degenerated.

Research Products

• [Int'l Joint Research] Kiel University(ドイツ)
• [Journal Article] How do environmental factors influence life cycles and development? An experimental framework for early-diverging metazoans. (2014)
  • Author(s): Bosch T, Adamska M, Augustin R, Domazet-Loso T, Foret S, Fraune S, Funayama N, Grasis J, Hamada M, Hatta M, Hobmayer B, Kawai K, Klimovich A, Manuel M, Shinzato C, Technau U, Yum S, Miller DJ.
  • Journal Title: BioEssays Volume: 36 Issue: 12 Pages: 1185-94
  • DOI: 10.1002/bies.201400065
  • Peer Reviewed / Open Access
• [Presentation] Molecular interaction and genome evolution in the green Hydra and Chlorella symbiosis (2015)
  • Author(s): Mayuko Hamada
  • Organizer: International Workshop Animal evolution: new perspectives from early emerging metazoans
  • Place of Presentation: Evangelische Akademie Tutzing, Germany
  • Year and Date: 2015-09-14
  • Int'l Joint Research
• [Presentation] グリーンヒドラ―クロレラ共生系における分子相互作用とゲノム進化 (2015)
  • Author(s): 濱田麻友子、新里宙也、Ulrich Kurn、佐藤矩行、Thomas C.G. Bosch
  • Organizer: 日本藻類学会第３９回福岡大会
  • Place of Presentation: 九州大学箱崎キャンパス
  • Year and Date: 2015-03-20 – 2015-03-22
• [Presentation] ゲノムから見た刺胞動物‐藻類共生システム (2014)
  • Author(s): 濱田麻友子
  • Organizer: 平成２６年度日本動物学会中部支部大会シンポジウム「海産無脊椎動物研究の最前線」
  • Place of Presentation: のと勤労者プラザ
  • Year and Date: 2014-11-22 – 2014-11-24
  • Invited
• [Presentation] グリーンヒドラを用いた共生システムにおける分子的相互作用とゲノム進化の解析 (2014)
  • Author(s): 濱田麻友子，佐藤 矩行，Thomas C. G. Bosch
  • Organizer: 第85回日本動物学会仙台大会
  • Place of Presentation: 東北大学川内北キャンパス
  • Year and Date: 2014-09-10 – 2014-09-14
• [Presentation] The Hydra viridissima /Chlorella symbiosis revisited: Understanding a complex team of players at the base of animal evolution (2013)
  • Author(s): Mayuko Hamada
  • Organizer: International Workshop “Unravelling the Developmental Regulatory Network in Early Animals"”
  • Place of Presentation: Evangelische Akademie, Tutzing, Germany