Mechanism of antifreeze proteins for improving the freezing- and cold-tolerance in the nematode Caenorhabditis elegans

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15787
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: The University of Tokyo
• Principal Investigator: Kuramochi Masahiro 東京大学, 大学院新領域創成科学研究科, 助教 (60805810)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 不凍タンパク質 / 線虫 / 低温耐性 / 熱ヒステリシス / 氷晶結合面 / 蛍光イメージング

Outline of Final Research Achievements

Antifreeze Protein (AFP) has a unique function for inhibiting the ice crystal growth. Interestingly, transgenic Caenorhabditis elegans expressing AFP at body wall muscles could survive at unfrozen low temperatures. AFP expressing transgenic-worms had cold tolerance. AFP probably has a function at unfrozen low temperatures for improving the cold tolerance of worms. It is not the ice-AFP interaction. To observe the AFP mechanism in vivo, several AFP mutants were introduced at body wall muscles in C. elegans. We then evaluated the cold tolerance of those transgenic worms at unfrozen low temperatures. In addition, we analysed AFP expression level and cellular damages by fluorescence imaging. We found that AFP function for inhibiting ice crystal growth correlates with the cold tolerance of worms at unfrozen low temperature.

Free Research Field

生物物理

Academic Significance and Societal Importance of the Research Achievements

不凍タンパク質（AFP）を利用した生体組織の低温保存法が期待されています。一方、その機能を生体レベルで検証する取り組みは少ないです。本研究では、非凍結温度における線虫低温耐性を調べることで、低温保存に有効なAFPの特徴を探索しました。複数のAFP変異体を用いた解析から、線虫低温耐性とAFP機能の関係性を示すことができ、生体組織の低温保存に有益なAFP性能の基礎科学知見を得ることができました。