Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
PLoS One. 2012;7(4):e35043. doi: 10.1371/journal.pone.0035043. Epub 2012 Apr 9.
Freeze-drying sperm has been developed as a new preservation method where liquid nitrogen is no longer necessary. An advantage of freeze-drying sperm is that it can be stored at 4 °C and transported at room temperature. Although the successful freeze-drying of sperm has been reported in a number of animals, the possibility of long-term preservation using this method has not yet been studied.
METHODOLOGY/PRINCIPAL FINDINGS: Offspring were obtained from oocytes fertilized with rat epididymal sperm freeze-dried using a solution containing 10 mM Tris and 1 mM EDTA adjusted to pH 8.0. Tolerance of testicular sperm to freeze-drying was increased by pre-treatment with diamide. Offspring with normal fertility were obtained from oocytes fertilized with freeze-dried epididymal sperm stored at 4 °C for 5 years.
Sperm with -SS- cross-linking in the thiol-disulfide of their protamine were highly tolerant to freeze-drying, and the fertility of freeze-dried sperm was maintained for 5 years without deterioration. This is the first report to demonstrate the successful freeze-drying of sperm using a new and simple method for long-term preservation.
冷冻干燥精子已被开发为一种新的保存方法，不再需要使用液氮。冷冻干燥精子的一个优点是可以在 4°C 下储存，并在室温下运输。尽管已经有报道称在许多动物中成功地冷冻干燥了精子，但使用这种方法进行长期保存的可能性尚未得到研究。
方法/主要发现：通过使用含有 10 mM Tris 和 1 mM EDTA 的溶液将 pH 值调节至 8.0 来冷冻干燥大鼠附睾精子，然后用该溶液使卵母细胞受精，获得了后代。通过预先用二酰胺处理来增加睾丸精子对冷冻干燥的耐受性。从在 4°C 下储存 5 年的冷冻干燥附睾精子中受精的卵母细胞获得了具有正常生育能力的后代。
具有半胱氨酸-二硫键中 -SS- 交联的精子对冷冻干燥具有高度耐受性，并且冷冻干燥精子的生育能力在 5 年内没有恶化。这是首次报道使用新的简单方法成功地冷冻干燥精子以进行长期保存。
