Esaki Ritsuko, Ueda Hideto, Kurome Mayuko, Hirakawa Kazumasa, Tomii Ryo, Yoshioka Hiroki, Ushijima Hitoshi, Kuwayama Masashige, Nagashima Hiroshi
Laboratory of Developmental Engineering, Department of Life Science, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan.
Biol Reprod. 2004 Aug;71(2):432-7. doi: 10.1095/biolreprod.103.026542. Epub 2004 Mar 24.
This study describes a cryopreservation method for porcine in vitro-produced (IVP) embryos using as a model parthenogenetic embryos derived from in vitro-matured (IVM) oocytes. IVP embryos at the expanded blastocyst stage were cryopreserved by vitrification using the minimum volume cooling (MVC) method and exhibited an embryo survival rate of 41.2%. Survival was then significantly improved (83.3%, P < 0.05) by decreasing the amount of cytoplasmic lipid droplets (delipation) prior to vitrification. IVP embryos at the 4-cell stage also survived cryopreservation when vitrified after delipation (survival rate, 36.0%), whereas post-thaw survival of nondelipated embryos was quite low (9.7%). Furthermore, it was demonstrated that porcine IVP morulae can be cryopreserved by vitrification following delipation by a noninvasive method (survival rate, 82.5%). These results clearly confirm that porcine embryos derived from IVM oocytes can be effectively cryopreserved with high embryo survival using the MVC method in conjunction with delipation.
本研究描述了一种猪体外生产（IVP）胚胎的冷冻保存方法，使用体外成熟（IVM）卵母细胞来源的孤雌胚胎作为模型。扩张囊胚阶段的IVP胚胎采用最小体积冷却（MVC）法进行玻璃化冷冻保存，胚胎存活率为41.2%。然后，通过在玻璃化冷冻前减少细胞质脂滴数量（去脂），存活率显著提高（83.3%，P<0.05）。4细胞阶段的IVP胚胎在去脂后进行玻璃化冷冻时也能在冷冻保存后存活（存活率为36.0%），而未去脂胚胎的解冻后存活率相当低（9.7%）。此外，还证明了猪IVP桑葚胚可以通过非侵入性方法去脂后进行玻璃化冷冻保存（存活率为82.5%）。这些结果清楚地证实，使用MVC法结合去脂，可以有效地冷冻保存IVM卵母细胞来源的猪胚胎，并具有较高的胚胎存活率。
