For the first time, a research group led by Professor Teruhiko Wakayama of the University of Yamanashi succeeded in producing healthy offspring from freeze-dried sperm of mice stored in a desk drawer at room temperature for over a year.It has been shown that animal genetic resources can be safely and long-term conserved as well as plant species.
Conservation of animal and plant genetic resources is essential for maintaining species diversity.However, unlike plants, germ cells and somatic cells of animals require liquid nitrogen and an ultra-low temperature freezer, so maintenance costs are enormous.If the supply of liquid nitrogen or electric power is stopped due to an earthquake or the like, the cells will melt and die.
In 1998, the research group succeeded in producing pups from freeze-dried sperm for the first time in the world.However, it could only be stored for one month at room temperature, and a refrigerator was required for long-term storage.After that, various drying methods were devised, but since freeze-drying technology is used all over the world and can be stored anywhere, it has been required to develop a long-term storage technology for sperm by freeze-drying.
This time, the research group found out that the cause that can be stored only for a short period of time at room temperature is the air mixed in the glass ampoule bottle, and created a high vacuum ampoule bottle by non-destructive inspection of the ampoule bottle.When this ampoule bin was stored at room temperature for 100 year or more in a desk drawer, the degree of DNA damage and fertility of sperms were examined, and then embryo transfer was performed, 3 or more healthy offspring were obtained. ..The sperm production rate is about the same as that of sperm stored for XNUMX months, and it seems that long-term storage is possible.
In the future, if the reliability of this method can be proved, not only will animal genetic resources be safely stored for a long time at room temperature like plant seeds, but also a huge number of genetically modified mice produced worldwide every year will be able to be stored. Significant reductions in maintenance costs and sperm storage costs in fertility treatment can be expected.
Paper information:[Scientific Reports] Assessing the tolerance to room temperature and viability of freeze-dried mice spermatozoa over long-term storage at room temperature under vacuum