Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, 630090, Russia; Novosibirsk State University, Novosibirsk, 630090, Russia.
Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, 630090, Russia.
Arch Biochem Biophys. 2019 Jul 15;669:32-38. doi: 10.1016/j.abb.2019.05.017. Epub 2019 May 23.
Embryos cryopreservation is a widely used technology for genetic resources storage. Cryopreservation suppresses cell respiration, but very little is known about the changes that occur with mitochondria at low temperatures. We used Raman spectroscopy to investigate photoresponse and redox state of cytochromes in the respiratory electron transport chain (ETC) in early mouse embryos during cooling. Redox state of cytochromes was probed by the intensity of cytochrome resonance Raman lines. Photoinduced reactions of cytochromes were used to study the changes in the rates of redox reactions. It is found that the rate of cytochrome photoresponse detected by Raman spectra abruptly changes when embryos are cooled below -50 °C. Raman mapping revealed that the average intensity of cytochrome Raman peaks at -65 °C is higher than at -40 °C. Cytochrome b reduction was found in embryos frozen below -50 °C when irradiated with 532 nm laser radiation. These effects were observed for cells frozen in aqueous solutions of two different cryoprotectants: glycerol and propylene glycol. Raman spectroscopy of cytochromes reveals the abrupt changes in the ETC work of frozen mouse embryos at temperatures below -50 °C. We suggest that similar phenomena can be found in various cell types.
胚胎冷冻保存是一种广泛应用于遗传资源储存的技术。冷冻保存抑制了细胞呼吸，但对于线粒体在低温下发生的变化知之甚少。我们使用拉曼光谱技术研究了在冷却过程中早期小鼠胚胎呼吸电子传递链（ETC）中细胞色素的光反应和氧化还原状态。细胞色素的氧化还原状态通过细胞色素共振拉曼线的强度来探测。细胞色素的光诱导反应用于研究氧化还原反应速率的变化。结果发现，当胚胎冷却到-50°C 以下时，通过拉曼光谱检测到的细胞色素光反应速率突然发生变化。拉曼图谱显示，在-65°C 时细胞色素拉曼峰的平均强度高于-40°C。当用 532nm 激光辐射照射冷冻在-50°C 以下的胚胎时，发现细胞色素 b 被还原。这些效应在两种不同的冷冻保护剂：甘油和丙二醇的水溶液中冷冻的细胞中观察到。细胞色素的拉曼光谱揭示了在-50°C 以下温度下冷冻小鼠胚胎 ETC 工作的突然变化。我们认为，类似的现象可能存在于各种细胞类型中。
