Investigation of key regulators of heterosis in allopolyploid microalgae

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04847
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 27040:Biofunction and bioprocess engineering-related
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Maeda Yoshiaki 東京農工大学, 工学(系)研究科(研究院), 助教 (30711155)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 異質倍数体 / 雑種強勢 / 微細藻類 / 珪藻 / ゲノミクス / トランスクリプトミクス

Outline of Final Research Achievements

The marine pennate diatom Fistulifera solaris is the only allopolyploid microalga, which is believed to be generated by the inter-species hybridization. It is well known that allopolyploid organisms tend to exhibit superior phenotypes as compared to their parent species. This phenomenon is called heterosis, and its molecular mechanism has been investigated using allopolyploid animals and plants. In this study, the key factors potentially involved in the heterosis in F. solaris, which also attracts attentions as a promising host of biofuel producer due to the high lipid accumulation phenotype, was investigated by nanopore sequencing for chromosome-level assembly of the genome, and gene expression analyses. As a result, some remarkable genomic features including the tandemly repeated genes involved in the lipid synthesis were found. These features were not found in the genome of the closely related diatom which belongs to the same Fistulifera genus but is not an allopolyploid organism.

Free Research Field

生物工学

Academic Significance and Societal Importance of the Research Achievements

異質倍数体珪藻F. solarisのゲノム構造は、これまでの研究においても解析されている。しかし、従来のシークエンシング法ではカバーできない領域があり、染色体レベルでのアセンブリングは行えていなかった。本研究では、これまでの解析できなかった領域のDNA配列を取得し、染色体構造全体の把握に成功した。新たに配列取得した領域には、タンデムリピート構造を持つ脂質生合成遺伝子など、他の微細藻類には見られない、異質倍数体珪藻に特有の特徴が発見された。新たに得られた知見は、微細藻類の脂質代謝への理解と、バイオ燃料をはじめとする有用物質生産の効率化に有用であることから、学術的、および社会的に意義がある。