title: Effects of gonadotrophin treatments on meiotic and developmental competence of oocytes in porcine primordial follicles following xenografting to nude mice.
abstract: Our objective was to improve the developmental ability of oocytes in porcine primordial follicles xenografted to nude mice, by treating the host mice with gonadotrophins to accelerate follicular growth. Ovarian tissues from 20-day-old piglets, in which most of the follicles were primordial, were transplanted under the kidney capsules of ovariectomized nude mice. Gonadotrophin treatments were commenced around 60 days after vaginal cornification in the mice. Ovarian grafts were obtained 2 or 3 days after treatment with equine chorionic gonadotrophin (eCG-2 and eCG-3 groups), after porcine FSH infusion for 7 or 14 days, or after infusion of porcine FSH for 14 days with a single injection of estradiol antiserum (FSH-7, FSH-14 and FSH-14EA groups, respectively). Gonadotrophin treatments accelerated follicular growth within the xenografts compared with that in control mice given no gonadotrophins, consistent with higher (P < 0.05) circulating inhibin levels in the gonadotrophin-treated mice. In contrast, circulating mouse FSH levels were significantly (P < 0.05) depressed. We recovered large numbers of full-sized oocytes with meiotic competence to the mature stage from the eCG-3, FSH-7, and FSH-14EA, unlike in the control group. Moreover, 56% of matured oocytes with the first polar body (n = 39) were fertilized in vitro in the FSH-14EA group. After in vitro fertilization and subsequent culture for 7 days, one blastocyst was obtained from each of the eCG-3, FSH-7 and, FSH-14EA groups, whereas no blastocysts appeared in the other groups. Exogenous gonadotrophins--not mouse FSH--stimulated the growing follicles that had developed from the primordial follicles in the xenografts: the effects were incomplete but improved to some extent the meiotic and developmental abilities of the oocytes.
authors.affiliation: Genetic Diversity Department, National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan. kaneko@nias.affrc.go.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kaneko
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Junko
authors.initials: J
authors.lastname: Noguchi
authors.forename: Manabu
authors.initials: M
authors.lastname: Ozawa
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ohnuma
authors.forename: Naoki
authors.initials: N
authors.lastname: Maedomari
authors.forename: Naomi
authors.initials: N
authors.lastname: Kashiwazaki
mesh_terms: D000818:Animals; D004622:Embryo, Mammalian / Q000033:anatomy & histology; D047108:Embryonic Development; D004958:Estradiol / Q000276:immunology / Q000378:metabolism; D005260:Female; D005307:Fertilization in Vitro; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000494:pharmacology; D006064:Gonadotropins, Equine / Q000494:pharmacology; D006065:Gonadotropins, Pituitary / Q000494:pharmacology*; D007106:Immune Sera / Q000494:pharmacology; D007265:Inhibins / Q000097:blood; D008540:Meiosis / Q000187:drug effects; D051379:Mice; D008819:Mice, Nude; D009865:Oocytes / Q000187:drug effects* / Q000502:physiology; D009866:Oogenesis / Q000187:drug effects*; D006080:Ovarian Follicle / Q000187:drug effects / Q000637:transplantation*; D013552:Swine; D014183:Transplantation, Heterologous
chemical_list: D006064:Gonadotropins, Equine; D006065:Gonadotropins, Pituitary; D007106:Immune Sera; D004958:Estradiol; D007265:Inhibins; D005640:Follicle Stimulating Hormone