title: Bovine oocytes vitrified by the open pulled straw method and used for somatic cell cloning supported development to term.
abstract: The objective of the present study was to determine if oocytes vitrified by the open pulled straw (OPS) method could subsequently be used to produce somatic cell cloned cattle. Post-thaw survival rates were 77.0, 79.1, 97.2 and 97.5% for oocytes vitrified with EDFS30 (15% ethylene glycol, 15% dimethyl sulfoxide, ficoll and sucrose), EDFS40 (20% ethylene glycol, 20% dimethyl sulfoxide, ficoll and sucrose), EDFSF30 (15% ethylene glycol, 15% dimethyl sulfoxide, ficoll, sucrose and FBS) and EDFSF40 (20% ethylene glycol, 20% dimethyl sulfoxide, ficoll, sucrose and FBS), respectively. The parthenogenetic blastocyst rates of the vitrified-thawed oocytes activated with 5 microM of the calcium ionophore A23187 for 5 min and 2 microM of 6-dimethylaminopurin (6-DMAP) for 4h ranged from 10.3 to 23.0%, with the highest group not significantly differing from that of the controls (33.2%). In total, 722 vitrified-thawed oocytes were used as recipients for nuclear transfer, of which 343 fused (47.6%). Fifty-six (16.3%) of the reconstructed embryos reached the blastocyst stage after 7d of in vitro culture. Twenty-four blastocysts derived from vitrified-thawed oocytes were transferred to six Luxi yellow cattle recipients. Two recipients (33%) were diagnosed pregnant; one aborted 97 d after transfer, whereas the other delivered a cloned calf after 263 d. As a control, 28 synchronous Luxi yellow cattle recipients each received a single blastocyst produced using a fresh oocyte as a nuclear recipient; 10 recipients were diagnosed pregnant, of which 6 (21.4% of the original 28) delivered cloned calves. In conclusion, bovine oocytes vitrified by the OPS method and subsequently thawed supported development (to term) of somatic cell cloned embryos.
authors.affiliation: College of Animal Science and Technology, China Agricultural University, Beijing 100094, China.
authors.forename: Yun-Peng
authors.initials: YP
authors.lastname: Hou
authors.forename: Yun-Ping
authors.initials: YP
authors.lastname: Dai
authors.forename: Shi-En
authors.initials: SE
authors.lastname: Zhu
authors.forename: Hua-Bin
authors.initials: HB
authors.lastname: Zhu
authors.forename: Tong-Yi
authors.initials: TY
authors.lastname: Wu
authors.forename: Guo-Chun
authors.initials: GC
authors.lastname: Gong
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Wang
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.forename: Rong
authors.initials: R
authors.lastname: Wan
authors.forename: Ning
authors.initials: N
authors.lastname: Li
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001755:Blastocyst / Q000502:physiology; D002417:Cattle / Q000196:embryology / Q000502:physiology; D019976:Cloning, Organism; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000502:physiology; D010312:Parthenogenesis; D011247:Pregnancy; D011256:Pregnancy Outcome