title: Employing mated females as recipients for transfer of cloned dog embryos.
abstract: It has been suggested that co-transferring parthenogenetic embryos could improve the pregnancy success rate with cloned embryos in mammals. As an alternative to co-transferring parthenotes, in dogs we employed recipient females that possessed in vivo-fertilised embryos as a result of mating to determine whether mated bitches could be suitable recipients for cloned embryos. The effect of using mated recipients on implantation and pregnancy rates of canine somatic cell nuclear transfer embryos was also determined. Cloned embryos were transferred into the oviducts of naturally synchronous females that had mated with male dogs before ovulation. The pregnancy rate appeared to be similar between mated recipients (50%) and non-mated recipients (28.57%; P>0.05). However, the delivery rate of cloned pups was significantly higher in mated recipients than non-mated recipients (10.53 vs 2.38%; P<0.05). A decrease in progesterone levels in the mated recipients before the due date induced natural delivery. However, cloned pups in non-mated recipients were delivered by Caesarean section because the fall in progesterone concentration in these females did not occur until the due date. The present study demonstrated for the first time that mated female dogs can be used as recipients for cloned embryos.
authors.affiliation: Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 151-744, Korea.
authors.forename: Geon A
authors.initials: GA
authors.lastname: Kim
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Oh
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Park
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Kim
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Park
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Lim
authors.forename: Sung Keun
authors.initials: SK
authors.lastname: Kang
authors.forename: Goo
authors.initials: G
authors.lastname: Jang
authors.forename: Byeong Chun
authors.initials: BC
authors.lastname: Lee
mesh_terms: D000818:Animals; D001483:Base Sequence; D019976:Cloning, Organism / Q000379:methods / Q000662:veterinary*; D017931:DNA Primers / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004285:Dogs; D004624:Embryo Transfer / Q000379:methods / Q000662:veterinary*; D005260:Female; D005838:Genotype; D008297:Male; D008969:Molecular Sequence Data; D053652:Nuclear Transfer Techniques / Q000662:veterinary*; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000662:veterinary; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial