Creation of fundamental and universal female and male concepts

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22446
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 45:Biology at organismal to population levels and anthropology, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Nozaki Hisayoshi 東京大学, 大学院理学系研究科(理学部), 特任研究員 (40250104)
• Co-Investigator(Kenkyū-buntansha): 森 稔幸 大阪大学, 微生物病研究所, 助教 (00462739) ; 関本 弘之 日本女子大学, 理学部, 教授 (20281652) ; 三角 修己 山口大学, 大学院創成科学研究科, 准教授 (90583625)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: 進化 / 雌雄性 / 性 / GCS1 / 緑藻ボルボックス系列 / ミカヅキモ / マラリア原虫 / 紅藻シゾン

Outline of Final Research Achievements

Examination of the bisexual strain of the volvocine green alga Pleodorina demonstrated that production of male or female gametes was correlated with the increase or decrease, respectively, of expression of both MID/OTOKOGI and GCSI genes. This is a common characteristic of eukaryotes in which both genes embody females and males, and was also observed in the hermaphrodites. An effective transformation protocol of the sex-determining gene CpMinus1 in Closterium of the terrestrial plant lineage was established, and expression of the tag-protein of this gene was studied. We also initiated research on the epigenetic regulation of germline differentiation factors in the malaria parasite Plasmodium falciparum. In the red alga Cyanidioschizon culture, the transcript levels of Mind1 and Spo11 homologs involved in meiosis were increased 5.4- and 2.5-fold, respectively, compared to nitrogen-enrichedconditions, suggesting the presence of sex in the unicellular red algae.

Free Research Field

進化生物学

Academic Significance and Societal Importance of the Research Achievements

本研究課題は「メス」と「オス」が同型配偶の原始的な性からそれぞれの真核生物の系統で「基本的に同じ原理」で進化したという作業仮説（図1）に基づく。この仮説が正しければ真核生物の根本原理に立脚した「新しいメスとオスの概念」が創出できると確信し、開始したが、オスとGCS1と転写型性決定遺伝子の普遍的な関係は緑色植物では明らかになった。更に今後、扱う生物によって細分化されていた性関連の学問体系を大きく統合・変革させ、「新しいメスとオスの概念」によって統一的に「性 (sex)」を扱う新体系に発展すると期待される。