title: Production of live piglets following cryopreservation of embryos derived from in vitro-matured oocytes.
abstract: We have successfully produced healthy piglets following cryopreservation of embryos derived from oocytes matured and fertilized in vitro. The appropriate timing of cryopreservation pretreatment (removal of cytoplasmic lipid droplets [delipation] and vitrification) was initially determined using parthenogenetic embryos derived from in vitro-matured (IVM) oocytes. Viable embryos were obtained at the highest rate when embryos were delipated at the four- to eight-cell stages (Day 2 of embryo culture) and were vitrified approximately 15 h later (Day 3) by means of the minimum volume cooling method. After cryopreservation of embryos derived from oocytes matured and fertilized in vitro under the most appropriate conditions, 401 embryos were transferred to five recipient gilts, and the recipients all became pregnant. At autopsy of one of the recipients, which had received 47 embryos, eight fetuses (17.0%) were found. Three recipients each gave birth to two to four piglets (1.4%-6.0%). These results demonstrate that normal offspring can be produced from vitrified porcine embryos derived from IVM oocytes by a strategic combination of delipation and vitrification at the early cleavage stages. This approach has great potential in the reproduction of micromanipulated porcine embryos, such as cloned and sperm-injected embryos, produced from IVM oocytes.
authors.affiliation: Laboratory of Developmental Engineering, Department of Life Science, School of Agriculture, Meiji University, Tama, Kawasaki 214-8571, Japan. hnagas@isc.meiji.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagashima
authors.forename: Katsumi
authors.initials: K
authors.lastname: Hiruma
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Saito
authors.forename: Ryo
authors.initials: R
authors.lastname: Tomii
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ueno
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakayama
authors.forename: Hitomi
authors.initials: H
authors.lastname: Matsunari
authors.forename: Mayuko
authors.initials: M
authors.lastname: Kurome
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D015925:Cryopreservation; D003593:Cytoplasm / Q000378:metabolism; D004558:Electric Stimulation; D004624:Embryo Transfer; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D008055:Lipids / Q000302:isolation & purification; D008297:Male; D009865:Oocytes / Q000502:physiology*; D009924:Organ Culture Techniques; D010312:Parthenogenesis / Q000502:physiology; D011247:Pregnancy; D013552:Swine; D016707:Tissue Fixation
chemical_list: D008055:Lipids