title: Production of viable piglets for the first time using sperm derived from ectopic testicular xenografts.
abstract: Xenografting of testicular tissue into immunodeficient mice is known to be a valuable tool for facilitating the development of immature germ cells present in mammalian gonads. Spermatogenesis in xenografts and/or in vitro embryonic development to the blastocyst stage after ICSI of xenogeneic sperm has already been reported in large animals, including pigs; however, development of the embryos to term has not yet been confirmed. Therefore, in pigs, we evaluated the in vivo developmental ability of oocytes injected after ICSI of xenogeneic sperm. Testicular tissues prepared from neonatal piglets, which contain seminiferous cords consisting of only gonocytes/spermatogonia, were transplanted under the back skin of castrated nude mice. Between 133 and 280 days after xenografting, morphologically normal sperm were recovered, and a single spermatozoon was then injected into an in vitro matured porcine oocyte. After ICSI, the oocytes were electrostimulated and transferred into estrus-synchronized recipients. Two out of 23 recipient gilts gave birth to six piglets. Here, we describe for the first time that oocytes fertilized with a sperm from ectopic xenografts have the ability to develop to viable offspring in large mammals.
authors.affiliation: Division of Animal Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kaneko
authors.forename: Tamas
authors.initials: T
authors.lastname: Somfai
authors.forename: Naoki
authors.initials: N
authors.lastname: Maedomari
authors.forename: Manabu
authors.initials: M
authors.lastname: Ozawa
authors.forename: Junko
authors.initials: J
authors.lastname: Noguchi
authors.forename: Junya
authors.initials: J
authors.lastname: Ito
authors.forename: Naomi
authors.initials: N
authors.lastname: Kashiwazaki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002369:Castration; D004558:Electric Stimulation; D005260:Female; D050498:Live Birth; D008297:Male; D051379:Mice; D008819:Mice, Nude; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic / Q000662:veterinary*; D013091:Spermatogenesis; D013552:Swine; D013737:Testis / Q000637:transplantation*; D013997:Time Factors; D014183:Transplantation, Heterologous