Identification of beneficial genes on non-recombining regions by using heavy-ion deletion mapping(Fostering Joint International Research)

2018 Fiscal Year Final Research Report

• Project/Area Number: 15KK0264
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Science in genetics and breeding
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Kazama Yusuke 国立研究開発法人理化学研究所, 仁科加速器科学研究センター, チームリーダー (80442945)
• Research Collaborator: Filatov Dmitry A. オックスフォード大学, 植物科学部, 教授 ; Krasovec Marc
• Project Period (FY): 2016 – 2018
• Keywords: 重イオンビーム / 雌雄異株植物 / ヒロハノマンテマ / 性染色体 / 性決定 / 遺伝子量補正

Outline of Final Research Achievements

Some plants have distinct male and female individuals. One of them, Silene latifolia has XY-type sex chromosomes. We induced large deletions in the Y chromosome with heavy-ion beams, and constructed a gene map of the Y chromosome based on the arrangement of the deleted genes. Genoe sequencing of mutants with small deletions which have hermaphroditic flowers was conducted to identify the candidate genes that suppress the development of pistil. On the other hand, exhaustive gene expression analysis was carried out on large deletion mutants, revialing that the expression levels of the X-linked genes were doubled if a specific Y chromosome region was deleted. This result suggests that plant chromosomes have the gene dosage compensation which balances the expression level of X chromosome gene uniform between male and female and that the dosage compensation occurs immediately after loss of Y-linked genes.

Free Research Field

植物遺伝学

Academic Significance and Societal Importance of the Research Achievements

我々は、独自に作製したY染色体地図を活用することで、植物性染色体がオスとメスのX染色体連鎖遺伝子の発現量を均一に保つ「遺伝子量補正機構」をもち、それはY染色体上の一部の領域が欠落するとすぐに働くことを発見した。本発見は、植物性染色体が動物と同様の遺伝子量補正機構を獲得しうることを示した。さらに、遺伝子量補正は進化の過程で遺伝子ごとに徐々に起るのではなく、ひとたびY染色体上の相同遺伝子がなくなると即座に生じることを初めて捉えたという点で学術的に意義深い研究成果といえる。