A research team led by Professor Junya Ito of the Faculty of Veterinary Medicine, Azabu University announced that they have succeeded in developing an efficient vitrification preservation method for immature mouse eggs.
Currently, many genetically modified mice and rats, which serve as human disease models, are being developed and used in various fields including the medical field.Since these model animals require enormous space and cost to be maintained in a living body, they are usually stored in liquid nitrogen in the state of fertilized eggs at an ultra-low temperature.On the other hand, if the unfertilized egg can be stored in the state before fertilization, it is possible to easily produce hybrids, but it is difficult to store the unfertilized egg and the fertilization ability after storage is lowered. Was a problem.
In the research so far, this research team has succeeded in developing an ultra-low temperature preservation method (vitrification preservation method) for mature (second meiotic metaphase) eggs, which is a fertilizable stage among unfertilized mouse eggs. ..However, the efficiency of preservation of unfertilized eggs in the state of immature eggs (prophase first meiosis) existing in the ovary was extremely low, although there were successful cases by other groups.
Therefore, this time, the team aimed to improve and develop a vitrification preservation method for immature eggs by the minimum capacity vitrification method.As a result, when calcium contained in the conventional preservation solution is removed and a preservation solution using ethylene glycol as a frost damage protective agent is used, about half of the preserved immature eggs can be fertilized and even placental vesicles can be developed. I understood.Furthermore, as a result of transplanting the fertilized egg to the surrogate mother, the growth rate to the offspring, which was about 10% in the past, has improved to about 35%.
This result is considered to greatly contribute to the conservation of genetic resources such as bioresources.In addition, the preservation of unfertilized eggs is considered to be an important technique in human reproductive medicine in the future, and it is expected that this technique can be applied to the preservation of unfertilized human eggs.
Paper information:[PLOS ONE] Highly successful production of viable mice derived from vitrified germinal vesicle oocytes
