The investigation on mitochondrial sulfur respiration in the development o chicken embryo

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K19177
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 42:Veterinary medical science, animal science, and related fields
• Research Institution: Tohoku University
• Principal Investigator: Kikusato Motoi 東北大学, 農学研究科, 准教授 (90613042)
• Co-Investigator(Kenkyū-buntansha): 徳武 優佳子 信州大学, 学術研究院農学系, 助教 (90824657)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 硫黄呼吸 / 含硫アミノ酸 / ミトコンドリア / 鶏胚

Outline of Final Research Achievements

This study aimed to verify whether chicken embryos may acquire energy from mitochondrial sulfur respiration during the development. Chicken embryo fibroblast isolated from the fertilized eggs were incubated at normal atmospheric oxygen level (approximately 20%) or mild hypoxia (approx. 14-15%), which occurs during the chicken embryo development, in the absence of amino acids in the cultured medium. In the hypoxia conditions, the number of CEF in the amino acid-depleted medium was markedly reduced, while it was increased by the additions of sulfur amino acids, methionine and cysteine. This increase did not occur the additions of other amino acids. These results suggest that CEF could obtain the energy from the oxidation of methionine and cysteine in hypoxic conditions, while it is limited or supportive.

Free Research Field

動物生産科学

Academic Significance and Societal Importance of the Research Achievements

硫黄呼吸は細菌類で見出された生体現象であり、これまでに高等動物では哺乳動物のみで見つかっている。本研究より、孵卵中の鶏胚では補助的ではあるものの含硫アミノを用いて生体エネルギーを得ていることが示され、鳥類でも硫黄呼吸が生じている可能性が示唆された。このことは、鶏胚に多くの含硫アミノ酸が含まれる生理的意義の一つとして説明できる可能性がある。産業動物であるニワトリは孵化後の成長が重要であり、孵化直後は残存卵黄から栄養素を供給する。鶏胚を高酸素状態で孵卵し、含硫アミノ酸の消費を減らすことができれば、残存卵黄に含硫アミノ酸を多く含むことが可能になり、孵化後成長の増大が見込めるかもしれない。