Analysis of evolution of sexual reproductive system in Closterium peracerosum-strigosum-littorale complex, comparing sex-chromosome like regions

2016 Fiscal Year Final Research Report

• Project/Area Number: 24370038
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Biodiversity/Systematics
• Research Institution: Japan Women's University
• Principal Investigator: Sekimoto Hiroyuki 日本女子大学, 理学部, 教授 (20281652)
• Co-Investigator(Kenkyū-buntansha): 西山 智明 金沢大学, 学際科学実験センター, 助教 (50390688)
• Co-Investigator(Renkei-kenkyūsha): ABE Jun 日本女子大学, 理学部, 学術研究員 (10424764) ; TSUCHIKANE Yuki 日本女子大学, 理学部, 助教 (20434152)
• Research Collaborator: KAWAI Junko 日本女子大学, 理学部, 学術研究員 (30727673) ; OOTSUKI Ryo 日本女子大学, 理学部, 学術研究員 (10646962) ; KOMIYA Ayumi ; FUJIWARA Anri ; KANDA Naho ; KANAZAWA Manaki
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: ミカヅキモ / 性決定遺伝子 / 性染色体 / 有性生殖 / 生殖様式

Outline of Final Research Achievements

We focused on Closterium peracerosum-strigosum-littorale complex (C. psl. complex), which is one of the unicellular charophycean algae. They have two sexes: mating type plus (mt+) and mating type minus (mt-). However, the mechanism of sex determination had not been clarified. In this study, we found a gene, which was highly linked to mt- phenotype of the progenies. It encoded a putative transcription factor and was named CpMinus1. To evaluate the function, a construct for ectopic expression was prepared and introduced into mt+ strain. Among 6 stable transformants, 5 showed sexual reaction without mating partners, like as the case of homothallic strains. Two transformants (R5 and R6) tended to form zygotes with mt+ strain but not with mt- strain. The gene expression profile of strain R5 was drastically changed to that of mt- strains. We concluded that the CpMinus1 gene was responsible for both the expression of mt- phenotype and the suppression of mt+ phenotype in C. psl. complex.

Free Research Field

植物生殖生理学