Faculty of Life and Environmental Sciences, University of Yamanashi, Yamanashi, 400-8510, Japan.
Advanced Biotechnology Centre, University of Yamanashi, Yamanashi, 400-8510, Japan.
Sci Rep. 2018 Jul 13;8(1):10602. doi: 10.1038/s41598-018-28896-8.
Freeze-drying has been frequently used to preserve food and microorganisms at room temperature (RT) for extended periods of time; however, its application to mammalian species is difficult. Here, we developed a method to prolong the stability of freeze-dried (FD) mice spermatozoa at RT for more than one year without using any cryoprotectant agents. Our data showed that maintaining a vacuum in ampoules is critical to ensuring the viability of FD spermatozoa, as the stability of spermatozoa DNA increased when imperfectly vacuumed ampoules were detected using a non-destructive test and eliminated. Finally a large number of healthy offspring were obtained from mice oocytes fertilized with FD spermatozoa stored at RT for more than one year. Although the birth rate from three-month stored spermatozoa was lower than that from one-day stored spermatozoa, no further reduction was observed even in one-year stored spermatozoa. Therefore, FD spermatozoa preserved in this study were highly tolerant to warm temperatures. This method of storage shows a great potential for the preservation of genetic resources of mammalian species, such as genetically-modified mouse strains, without the use of electric power.
冻干技术常用于在室温（RT）下长时间保存食物和微生物；然而，将其应用于哺乳动物物种较为困难。在此，我们开发了一种方法，可在不使用任何冷冻保护剂的情况下，将冻干（FD）的精子在 RT 下的稳定性延长至一年以上。我们的数据表明，在安瓿中保持真空状态对于确保 FD 精子的活力至关重要，因为当使用非破坏性测试检测到不完全抽空的安瓿时，精子 DNA 的稳定性会增加，并被淘汰。最后，从在 RT 下储存超过一年的 FD 精子中受精的小鼠卵母细胞中获得了大量健康的后代。尽管从储存三个月的精子中获得的出生率低于从储存一天的精子中获得的出生率，但即使在储存一年的精子中也没有观察到进一步的降低。因此，本研究中保存的 FD 精子对高温具有高度的耐受性。这种储存方法显示出了巨大的潜力，可用于保存遗传资源，如遗传修饰的小鼠品系，而无需使用电力。
