title: Birth of piglets from in vitro-produced porcine blastocysts vitrified and warmed in a chemically defined medium.
abstract: We examined the effect of different embryo developmental stages, culture periods, and media on the cryotolerance of in vitro-produced porcine blastocysts. All media used for in vitro production, vitrification, and warming were chemically defined. When in vitro-produced embryos at the blastocyst and expanded blastocyst stages were vitrified using the Cryotop method on Day 5 or 6 (Day 0 = the day of IVF), the survival rate and hatching rate of expanded blastocysts after warming were higher than those of blastocysts. The viability after vitrification and warming of Day-6 embryos cultured in porcine blastocyst medium from Day 5 were higher than that of embryos cultured in porcine zygote medium 5. On the other hand, there were no significant differences on the cryotolerance between Day-5 embryos cultured in porcine zygote medium 5 and those replaced with porcine blastocyst medium on Day 4. There were no significant differences in viability between the embryonic ages of 5 and 6 days after vitrification and warming. When expanded blastocysts vitrified on Day 5 or 6 were surgically transferred to recipient gilts, all three recipients became pregnant in the Day-5 group, whereas only one out of three recipients became pregnant in the Day-6 group. These results indicate that the cryotolerance of porcine in vitro-produced blastocysts after vitrification appears to depend on the embryonic stage, culture period, and medium.
authors.affiliation: Research Institute for the Functional Peptides, Higashine, Yamagata, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Mito
authors.affiliation: Pathology and Pathophysiology Research Division, National Institute of Animal Health, Tsukuba, Ibaraki, Japan. Electronic address: kojiyos@affrc.go.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Yoshioka
authors.affiliation: Department of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Noguchi
authors.affiliation: Research Institute for the Functional Peptides, Higashine, Yamagata, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Yamashita
authors.affiliation: National Livestock Breeding Center, Miyazaki Station, Kobayashi, Miyazaki, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Misumi
authors.affiliation: Research Institute for the Functional Peptides, Higashine, Yamagata, Japan.
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Hoshi
authors.affiliation: Research Institute for the Functional Peptides, Higashine, Yamagata, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Hoshi
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D015925:Cryopreservation / Q000662:veterinary; D003470:Culture Media; D046149:Embryo Culture Techniques / Q000662:veterinary*; D004624:Embryo Transfer / Q000662:veterinary; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro; D011247:Pregnancy; D013552:Swine / Q000502:physiology*; D013997:Time Factors; D058989:Vitrification
chemical_list: D003470:Culture Media
keywords: Cryotolerance; Defined medium; Developmental stage; Pig Blastocyst; Vitrification