Assessment of mouse oocyte quality using Raman spectroscopy

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K18267
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Analytical chemistry; Biomedical engineering/Biomaterial science and engineering
• Research Institution: Shimane University (2018-2019); Kwansei Gakuin University (2017)
• Principal Investigator: Ishigaki Mika 島根大学, 学術研究院農生命科学系, 助教 (60610871)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: ラマン分光法 / 卵質評価 / 非破壊評価

Outline of Final Research Achievements

It was aimed to identify biomarkers for mice oocyte maturation in metaphase II in vivo and in situ using Raman spectroscopy. Principal component analysis of Raman data points of oocytes at Phase 13h, 15h, 18h, and 24h showed that the phosphoric acid concentration uniformly increased in oocytes with higher developmental competence than in oocytes at other maturation stages, and proteins were more phosphorylated. Furthermore, detections of higher concentration of unsaturated fatty acids in overmatured oocytes indicated that a decline in metabolic activity due to overmaturation induced a surplus of these lipid components. Upon assessing invasiveness by laser irradiation, about 50% irradiated oocytes progressed to morula and blastocyst stages in good conditions. Thus, Raman spectroscopy holds promise in evaluating oocyte maturation and quality based on molecular information in infertility treatment.

Free Research Field

分子分光学

Academic Significance and Societal Importance of the Research Achievements

本研究で得られた結果により、特に不妊治療分野において、卵子及び受精卵の新たな評価手法を提示できる可能性がある。レーザーによる影響が全くない条件を検討できれば、胚中タンパク質のリン酸化をラマン分光法によって非破壊、非染色に評価して受精能や発生能を予測し、受精卵を体内に戻すことができると予想される。卵質の分子レベルでの無侵襲評価という、不妊治療分野における医療技術の進歩に貢献できると考えられる。