title: [Vitrification of mouse blastocyst by open pulled straw (OPS) method at different temperature].
abstract: To examine the efficiency of EDFS and EFS for blastocyst cryopreservation and to provide information for preparation of vitrification medium at different temperature, the present investigation was conducted to establish a model for vitrification of domestic animal's blastocyst and human blastocyst using mouse blastocyst as a model and OPS (open pulled straw) as the container. When ambient temperature was 25 degrees C and heating plate temperature was 37 degrees C, mouse blastocysts were vitrified using 1-step OPS method, after thawing, the expanded blastocyst (EB) rates of EDFS40 and EFS40 group (92.31%, 92.30%) were not different from that of the control (97.26%) (P > 0.05), however, the hatched blastocyst (HB) rate of EDFS40 group (59.62%) was significantly lower than that of the control (83.56%); When 2-step method was adopted at the same temperature, mouse blastocyst was successfully cryopreserved with EDFS30 and EFS40, the post-thawing EB rate (95.69%, 95.05%) and HB rate(80.48%, 78.95%) of both EDFS30 and EFS40 groups did not differ from those of the control (P > 0.05). When ambient temperature was 25 degrees C and heating plate was free, the EB rate (85.96%) and HB (75.44%) of embryos vitrified with EDFS40 using 1-step OPS method were not statistically different from those of the control (96.05% and 82.89%, respectively) (P > 0.05); the EB and HB rates (92.03%-95.31%, 67.19%-76.76%) of embryos vitrified with EDFS30, EDFS40 and EFS40 using 2-step OPS method were similar to those of the control (P > 0.05). According to in vitro development of vitrified embryos, the promising group was chosen for embryo transfer to examine in vivo development of vitrified embryos. When vitrified blastocysts were transferred into uterus of pseudopregnant mouse, the pregnancy rate of receipts (90.90%) and birth rate of foster mother (37.33%) were similar to those of fresh embryos (91.67% and 42.33%) (P > 0.05). All data demonstrated that mouse blastocyst was successfully cryopreserved with EDFS30, EDFS40 and EFS40 at different temperature and using different procedures.
authors.affiliation: Laboratory of Animal Embryonic Biotechnology, College of Animal Science and Technology, China Agricultural University, Beijing 100094.
authors.forename: Qi En
authors.initials: QE
authors.lastname: Yang
authors.forename: Yun Peng
authors.initials: YP
authors.lastname: Hou
authors.forename: Zhong Qiang
authors.initials: ZQ
authors.lastname: Yang
authors.forename: Guang Bin
authors.initials: GB
authors.lastname: Zhou
authors.forename: Xiu Wei
authors.initials: XW
authors.lastname: Li
authors.forename: Shi En
authors.initials: SE
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D001831:Body Temperature; D015925:Cryopreservation / Q000379:methods*; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D013696:Temperature