Advancement of cryopreserved bovine embryo transfer usin anti-freeze protein

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06370
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 42010:Animal production science-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Sakatani Miki 国立研究開発法人農業・食品産業技術総合研究機構, 畜産研究部門, グループ長 (00355687)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 牛 / 体外受精 / 凍結保存 / 耐凍性 / 受胎率 / 不凍タンパク質

Outline of Final Research Achievements

This study investigated a method for cryopreservation of bovine in vitro produced (IVP) embryo using serum-free culture and freezing medium that does not reduce fertility and does not cause problem such as large offspring syndrome. To improve the cryodamage, we used Type III anti-freeze protein (AFP III). IVP blastocysts were cultured for 1 h with AFP III 1.0 ug/mL, and then cryopreserved with cryopreservation medium including 1.0 ug/mL AFP III. After thawing, the blastocysts frozen with AFP III showed the higher viability and their stress gene (HSPA1) expression was suppressed. It was suggested that the supplementation of AFP III enhanced the cryotolerance of IVP embryos. The results of embryo transfer also showed a higher conception rate than the control, indicating that the AFP III supplementation in serum-free freezing solution may increase cryotolerance and guarantee conception rate.

Free Research Field

家畜繁殖学

Academic Significance and Societal Importance of the Research Achievements

多くの胚を安価に生産できる体外受精凍結保存胚を利用することが増加する牛胚移植の需要を満たす。一方で凍結保存胚は受胎率が低くその改善が長く望まれている。本研究成果は一般の食品にも使われる不凍タンパク質を活用し、血清を含まない培養・凍結液を用いて融解後の生存性や移植成績もよい胚保存法を提示したことで、生産コストを抑えた効率的な牛生産に貢献することが期待される。