Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, Japan.
Advanced Biotechnology Center, University of Yamanashi, Yamanashi 400-8510, Japan.
J Reprod Dev. 2023 Aug 11;69(4):198-205. doi: 10.1262/jrd.2023-034. Epub 2023 Jun 23.
Although freeze-drying sperm can save space, reduce maintenance costs, and facilitate the transportation of genetic samples, the current method requires breakable, custom-made, and expensive glass ampoules. In the present study, we developed a simple and economical method for collecting freeze-dried (FD) sperm using commercially available plastic microtubes. Mouse epididymal sperm suspensions were placed in 1.5 ml polypropylene tubes, frozen in liquid nitrogen, and dried in an acrylic freeze-drying chamber, after which they were closed under a vacuum. The drying duration did not differ between the microtube and glass ampoule methods (control); however, the sperm recovery rate was higher using the microtube method, and the physical damage to the sperm after rehydration was also reduced. Intracytoplasmic sperm injection (ICSI) using FD sperm stored in microtubes at -30°C yielded healthy offspring without reducing the success rate, even after 9 months of storage. Air infiltration into all microtubes stored at room temperature (RT) within 2 weeks of storage caused a drastic decrease in the fertilization rate of FD sperm; underwater storage did not prevent air infiltration. RT storage of FD sperm in microtubes for 1 week resulted in healthy offspring after ICSI (5-18%), but the addition of silica gel or CaCl did not improve the success rate. Our novel microtube method is currently the simplest and most effective method for treating FD sperm, contributing to the development of alternative low-cost approaches for preserving and transporting genetic resources.
虽然冷冻干燥精子可以节省空间、降低维护成本并方便遗传样本的运输,但目前的方法需要易碎的、定制的和昂贵的玻璃安瓿。在本研究中,我们开发了一种简单经济的方法,使用市售的塑料微量离心管收集冷冻干燥(FD)精子。将小鼠附睾精子悬浮液置于 1.5 ml 聚丙烯管中,在液氮中冷冻,在丙烯酸冷冻干燥室中干燥,然后在真空下关闭。微管法和玻璃安瓿法的干燥时间没有差异(对照);然而,微管法的精子回收率更高,并且精子在复水后的物理损伤也减少。使用储存在-30°C 微管中的 FD 精子进行胞质内精子注射(ICSI),即使在储存 9 个月后,也不会降低成功率,从而产生健康的后代。所有储存在室温(RT)下的微管中的空气在储存后 2 周内渗透,导致 FD 精子的受精率急剧下降;水下储存不能防止空气渗透。在 RT 下将 FD 精子储存在微管中 1 周后,通过 ICSI 获得健康的后代(5-18%),但添加硅胶或 CaCl 并没有提高成功率。我们的新型微管方法是目前处理 FD 精子的最简单、最有效的方法,有助于开发替代的低成本方法来保存和运输遗传资源。