title: Open-pulled straw (OPS) vitrification of in vitro fertilised mouse embryos at various stages.
abstract: The present study was designed to investigate the cryotolerance of in vitro fertilised (IVF) mouse embryos at various preimplantation developmental stages. IVF mouse embryos were vitrified by the open-pulled straw (OPS) method. After warming, embryos were morphologically evaluated and assessed by their development to blastocysts, hatched blastocysts or term. The results showed that a high proportion (93.3-100.0%) of vitrified embryos at all developmental stages were morphologically normal after recovery. The developmental rate of vitrified 1-cell embryos to blastocyst (40.0%) or hatched blastocyst (32.7%) or term (9.3%) was significantly lower than that from other stages (P < 0.05). Vitrified embryos from 2-cell to early blastocyst stage showed similar blastocyst (71.8-89.5%) and hatched blastocyst rates (61.1-69.6%) and could develop to term without a significant loss of survival compared with those of fresh embryos (P > 0.05). Vitrified 2-cell embryos showed the highest survival rate in vivo (50.6%, 88/174), compared with that from other stages (9.3-30.5%, P < 0.05). The data demonstrate that the OPS method is suitable for the cryopreservation of IVF mouse embryos from 2-cell stage to early blastocyst stage without a significant loss of survival. Embryos at the 2-cell stage had the best tolerance for cryopreservation in the present study.
authors.affiliation: College of Animal Science and Technology, China Agricultural University, Beijing, PR China.
authors.forename: Chang-Liang
authors.initials: CL
authors.lastname: Yan
authors.forename: Qi-En
authors.initials: QE
authors.lastname: Yang
authors.forename: Guang-Bin
authors.initials: GB
authors.lastname: Zhou
authors.forename: Yun-Peng
authors.initials: YP
authors.lastname: Hou
authors.forename: Xue-Ming
authors.initials: XM
authors.lastname: Zhao
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Fan
authors.forename: Man-Qing
authors.initials: MQ
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
authors.forename: Shi-En
authors.initials: SE
authors.lastname: Zhu
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004624:Embryo Transfer / Q000662:veterinary; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D008297:Male; D051379:Mice / Q000196:embryology*; D011247:Pregnancy