2014 Fiscal Year Final Research Report

Symbiosis drove foraminiferal evolution

Research Project

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Project/Area Number	24340131
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Partial Multi-year Fund
Section	一般
Research Field	Stratigraphy/Paleontology
Research Institution	Japan Agency for Marine-Earth Science and Technology
Principal Investigator	TSUCHIYA Masashi 独立行政法人海洋研究開発機構, 海洋生物多様性研究分野, 技術研究員 (00435835)
Co-Investigator(Kenkyū-buntansha)	FUJITA Kazuhiko 琉球大学, 理学部, 准教授 (00343377) ISHIMURA Toyoho 茨城工業高等専門学校, 物質工学科, 准教授 (80422012)
Co-Investigator(Renkei-kenkyūsha)	CHIKARAISHI Yoshito 独立行政法人海洋研究開発機構, 生物地球化学研究分野, 主任研究員 (50455490) SAKAI Saburo 独立行政法人海洋研究開発機構, 生物地球化学研究分野, 技術研究員 (90359175) OGURI Kazumasa 独立行政法人海洋研究開発機構, 海洋生物多様性研究分野, 主任技術研究員 (10359177) TOYOFUKU Takashi 独立行政法人海洋研究開発機構, 海洋生物多様性研究分野, 主任研究員 (30371719) NOMAKI Hidetaka 独立行政法人海洋研究開発機構, 生物地球化学研究分野, 主任研究員 (90435834) YOSHIDA Takao 独立行政法人海洋研究開発機構, 海洋生物多様性研究分野, 主任技術研究員 (60399566) FREDERIC Sinniger 独立行政法人海洋研究開発機構, 海底資源研究開発センター, ポストドクトラル研究員 (10625940)
Project Period (FY)	2012-04-01 – 2015-03-31
Keywords	底生有孔虫 / 盗葉緑体 / 光合成 / 共生 / 系統進化 / 多様性 / 遺伝子 / 同位体
Outline of Final Research Achievements	Host-symbiont interactions are thought to be a key factor for adaptation and may be the driving force behind the evolution of endosymbiont-bearing foraminifers. We determined the kleptoplasts in a rocky-shore benthic foraminifer that originated from periphytic diatoms. Kleptoplasts were located near the host cell cortex, just under the pore plug, mainly along the dorsal side, which is important for oxygenic photosynthesis in light. The lifespan of kleptoplasts varied according to the intensity and duration of light irradiation and food availability. Host foraminifera metabolized food materials to maintain the activity of kleptoplasts and effectively utilized photosynthetic products from both organic and inorganic materials in response to the ambient environment. In fact, the trophic hierarchy according to the nitrogen isotopic composition of selected amino acids indicated that host foraminifers were primary producers as well as primary consumers in nature.
Free Research Field	実験古生物学，分子生態学