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

2015 Fiscal Year Final Research Report

• 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
• 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.

Free Research Field

ゲノム科学