title: Contribution of in vitro systems to preservation and utilization of porcine genetic resources.
abstract: Historically, the conservation or preservation of mammalian genetic resources, especially farm animals, has been conducted under in situ conditions by maintaining living individuals as "livestock." However, systems for laboratory in vitro embryo production using gametes such as spermatozoa and oocytes are now available, in addition to ex situ preservation methods for mammalian genetic resources. One of these methods is the cryopreservation of gametes, embryos, and gonadal tissues. In pigs, freezing of sperm is the most reliable and well-established method for this purpose. On the other hand, cryopreservation of female gametes (oocytes) and gonadal tissues-usually by vitrification-has been associated with very low efficacies. Recently, in our laboratory, some research themes related to this issue have been pursued. We have been focusing on advances in porcine in vitro embryo production systems, and here, we introduce recent data on the vitrification of porcine immature oocytes and gonadal tissues followed by their xenografting into host mice to produce gametes.
authors.affiliation: Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan; The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, Yamaguchi, Japan. Electronic address: kiku@affrc.go.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kaneko
authors.affiliation: Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakai
authors.affiliation: Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.
authors.forename: Tamas
authors.initials: T
authors.lastname: Somfai
authors.affiliation: Graduate School of Veterinary Science, Azabu University, Sagamihara, Kanagawa, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Kashiwazaki
authors.affiliation: National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000662:veterinary*; D046149:Embryo Culture Techniques / Q000662:veterinary*; D005260:Female; D008297:Male; D009865:Oocytes / Q000502:physiology*; D027724:Reproductive Techniques, Assisted / Q000662:veterinary*; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013552:Swine / Q000235:genetics*
keywords: Cryopreservation; Gene bank; Gonadal tissue; Oocyte; Pig; Vitrification