Integration mechanism of endosymbiotic algae as organelles through secondary endosymbioses

2015 Fiscal Year Final Research Report

• Project Area: "Matryoshka"-type evolution of eukaryotes
• Project/Area Number: 23117004
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: University of Tsukuba
• Principal Investigator: ISHIDA Ken-ichiro 筑波大学, 生命環境系, 教授 (30282198)
• Co-Investigator(Kenkyū-buntansha): INOUYE Isao 筑波大学, 生命環境系, 教授 (70168433) ; MATSUZAKI Motomichi 東京大学, 医学系研究科, 助教 (00511396) ; HIRAKAWA Yoshihisa 筑波大学, 生命環境系, 助教 (40647319)
• Project Period (FY): 2011-04-01 – 2016-03-31
• Keywords: 細胞内共生 / 色素体（葉緑体） / 進化 / 藻類 / 寄生虫 / 原生生物

Outline of Final Research Achievements

The hypothesis that the plastids drive the evolution and parasitization of organism has been studied in three organisms with different stages of secondary plastids: Hatena arenicola, chlorarachniophytes, and Perkinsus marinus. Comparative transcriptome analysis and genome analysis in Hatena, which has a kleptochloroplast, discovered 30 genes for possible endosymbiotic gene transfer (EGT) and provide an estimate for the level of integration. In the chlorarachniophytes with permanent secondary plastids, a part of cooperation mechanism between the endosymbiont and nucleus and the evolution of endosymbiont nuclear genome has been clarified, which greatly contributed to understanding the gain and maintenance mechanisms of secondary plastids. In Perkinsus, an oyster parasite, an efficient isolation method for the reduced plastids, which is essential for uncovering its function, has been established. This opens the door to clarifying the principle of parasitism acquisition.

Free Research Field

原生生物と植物の系統分類・進化学