title: Analysis of nuclear reprogramming in cloned miniature pig embryos by expression of Oct-4 and Oct-4 related genes.
abstract: Xenotransplantation is a rapidly expanding field of research and cloned miniature pigs have been considered as a model animal for it. However, the efficiency of somatic cell nuclear transfer (SCNT) is extremely low, with most clones resulting in early lethality and several kinds of aberrant development. A possible explanation for the developmental failure of SCNT embryos is insufficient reprogramming of the somatic cell nucleus by the oocyte. In order to test this, we analyzed the reprogramming capacity of differentiated fibroblast cell nuclei and embryonic germ cell nuclei with Oct-4 and Oct-4 related genes (Ndp5211, Dppa2, Dppa3, and Dppa5), which are important for embryonic development, Hand1 and GATA-4, which are important for placental development, as molecular markers using RT-PCR. The Oct-4 expression level was significantly lower (P<0.05) in cloned hatched blastocysts derived from fibroblasts and many of fibroblast-derived clones failed to reactivate at least one of the tested genes, while most of the germ cell clones and control embryos correctly expressed these genes. In conclusion, our results suggest that the reprogramming of fibroblast-derived cloned embryos is highly aberrant and this improper reprogramming could be one reason of the early lethality and post-implantation anomalies of somatic cell-derived clones.
authors.affiliation: Department of Theriogenology and Biotechnololgy, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Eugine
authors.initials: E
authors.lastname: Lee
authors.forename: So Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Sue
authors.initials: S
authors.lastname: Kim
authors.forename: Yeon Woo
authors.initials: YW
authors.lastname: Jeong
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Kim
authors.forename: Ok Jae
authors.initials: OJ
authors.lastname: Koo
authors.forename: Seon Mi
authors.initials: SM
authors.lastname: Park
authors.forename: M A
authors.initials: MA
authors.lastname: Hashem
authors.forename: M S
authors.initials: MS
authors.lastname: Hossein
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Son
authors.forename: Chang Kyu
authors.initials: CK
authors.lastname: Lee
authors.forename: Woo Suk
authors.initials: WS
authors.lastname: Hwang
authors.forename: Sung Keun
authors.initials: SK
authors.lastname: Kang
authors.forename: Byeong Chun
authors.initials: BC
authors.lastname: Lee
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics; D002478:Cells, Cultured; D019976:Cloning, Organism; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000378:metabolism; D005307:Fertilization in Vitro; D005333:Fetus / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D050991:GATA4 Transcription Factor / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005854:Germ Cells / Q000378:metabolism; D053652:Nuclear Transfer Techniques; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013552:Swine; D013556:Swine, Miniature / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D050991:GATA4 Transcription Factor; D050814:Octamer Transcription Factor-3; D012333:RNA, Messenger; C097341:helix-loop-helix protein, eHAND