title: Production of transgenic rats using young Sprague-Dawley females treated with PMSG and hCG.
abstract: The aim of this study was to examine the effects of gonadotrophin treatments on estrus synchronization and superovulation in young Sprague-Dawley (SD) rats that had not yet exhibited defined estrus cycles (5 to 7 weeks old), and to produce transgenic rats using these females as embryo donors and recipients. In Experiment 1, female rats were injected with PMSG and hCG (12.5, 25, 50 and 100 IU/kg each) and were mated with stud males. The reproductive performance of young rats were highest when PMSG and hCG at doses of 25 IU/kg each were injected (delivery rate 87.5%, nursing rate 92.9%). In Experiment 2, female rats were injected with PMSG and hCG (100, 150 and 300 IU/kg each) to induce superovulation. More eggs were recovered from the rats injected with PMSG and hCG at 150 and 300 IU/kg than from those treated with 100 IU/kg (33.4 and 41.3 vs. 13.3 eggs per female, respectively; p < 0.05). In Experiment 3, pronuclear-stage zygotes from 150 IU/kg PMSG/hCG-treated rats were used for microinjection of the fusion gene of bovine alpha S1-casein gene promoter and human growth hormone gene (2.8 kb), and the microinjected zygotes were transferred into the oviduct ampullae of the 25 IU/kg PMSG/hCG-treated rats. Seventeen transgenic rats were obtained from the 334 DNA-injected zygotes (5.1%). These results indicate that recipients and embryo donors for the production of transgenic rats can be prepared by the appropriate PMSG and hCG treatments of young SD rats, regardless of their estrus stages.
authors.affiliation: YS New Technology Inst. Inc., 519 Shimoishibashi, Ishibashi-machi, Shimotsuga-gun, Tochigi 329-0512, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hirabayashi
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: A
authors.initials: A
authors.lastname: Sekimoto
authors.forename: S
authors.initials: S
authors.lastname: Hochi
authors.forename: M
authors.initials: M
authors.lastname: Ueda
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D030801:Animals, Genetically Modified; D019677:Artificial Gene Fusion; D002364:Caseins / Q000235:genetics; D002417:Cattle; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology*; D004973:Estrus Synchronization / Q000379:methods*; D006064:Gonadotropins, Equine / Q000008:administration & dosage / Q000494:pharmacology*; D019382:Human Growth Hormone / Q000235:genetics; D006801:Humans; D008297:Male; D010060:Ovulation; D011401:Promoter Regions, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D015053:Zygote
chemical_list: D002364:Caseins; D006063:Chorionic Gonadotropin; D006064:Gonadotropins, Equine; D019382:Human Growth Hormone