Cryopreservation of porcine embryos derived from in vitro-matured oocytes.
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.
Esaki
Ritsuko
R
Laboratory of Developmental Engineering, Department of Life Science, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama, Kawasaki 214-8571, Japan.
Ueda
Hideto
H
Kurome
Mayuko
M
Hirakawa
Kazumasa
K
Tomii
Ryo
R
Yoshioka
Hiroki
H
Ushijima
Hitoshi
H
Kuwayama
Masashige
M
Nagashima
Hiroshi
H
D000818:Animals; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D066298:In Vitro Techniques; D009028:Morula / Q000166:cytology; D009865:Oocytes / Q000166:cytology*; D013552:Swine