title: Blastocyst formation, karyotype, and mitochondrial DNA of interspecies embryos derived from nuclear transfer of human cord fibroblasts into enucleated bovine oocytes.
abstract: OBJECTIVE
  To establish an interspecies somatic cell nuclear transfer (iSCNT) technique for deriving blastocysts having human chromosome complements without sacrificing human oocytes.
  
  
  METHODS
  Prospective, randomized study undertaken in vitro.
  
  
  METHODS
  University-affiliated hospital and laboratory, Seoul National University.
  
  
  METHODS
  Postpartum women with natural spontaneous vaginal delivery.
  
  
  METHODS
  Human cord fibroblasts were retrieved from five postpartum women from whom informed consent was obtained. After subculture and cryopreservation, serum-starved cells were transferred into enucleated bovine oocytes.
  
  
  METHODS
  Embryo development, karyotype, and the presence of mitochondrial DNA (mtDNA).
  
  
  RESULTS
  A total 1,742 oocytes were provided for iSCNT and results showed that both fibroblast batch and reconstruction method significantly affected iSCNT outcome. An iSCNT using a single DC pulse of 1.9-2.1 kV/cm for 20 microseconds yielded better rates of fusion (30%-56%) and cleavage (36%) than the other iSCNT protocols. Four to 9% interspecies embryos produced with the optimized method developed to morulae or blastocysts after cultured in a serum-free medium. Results from karyotyping demonstrated that 56% of interspecies embryos evaluated had human chromosome complements. In polymerase chain reaction (PCR) analysis of a single embryo, both human and bovine mtDNAs were detected until the 16-cell stage, whereas only the bovine mtDNA was found beyond the morula stage.
  
  
  CONCLUSIONS
  An iSCNT using human cord fibroblasts and bovine oocytes can yield blastocysts and the results of karyotyping and mtDNA analysis confirmed the feasibility of the iSCNT technique.
authors.affiliation: School of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.
authors.forename: Kyung H
authors.initials: KH
authors.lastname: Chang
authors.forename: Jeong M
authors.initials: JM
authors.lastname: Lim
authors.forename: Sung K
authors.initials: SK
authors.lastname: Kang
authors.forename: Byeong C
authors.initials: BC
authors.lastname: Lee
authors.forename: Shin Y
authors.initials: SY
authors.lastname: Moon
authors.forename: Woo S
authors.initials: WS
authors.lastname: Hwang
mesh_terms: D000328:Adult; D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D002417:Cattle; D002874:Chromosome Mapping; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D005347:Fibroblasts / Q000637:transplantation; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000502:physiology*; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial