title: Effect of synchronization of donor cells in early G1-phase using shake-off method on developmental potential of somatic cell nuclear transfer embryos in cattle.
abstract: In this study, we compared the developmental ability of somatic cell nuclear transfer (SCNT) embryos reconstructed with three bovine somatic cells that had been synchronized in G0-phase (G0-SCNT group) or early G1-phase (eG1-SCNT group). Furthermore, we investigated the production efficiency of cloned offspring for NT embryos derived from these donor cells. The G0-phase and eG1-phase cells were synchronized, respectively, using serum starvation and antimitotic reagent treatment combined with shaking of the plate containing the cells (shake-off method). The fusion rate in the G0-SCNT groups (64.2 ± 1.8%) was significantly higher than that of eG1-SCNT groups (39.2 ± 1.9%) (P < 0.05), but the developmental rates to the blastocyst stage of SCNT embryos per fused oocytes were similar for all groups. The overall production efficiency of the clone offspring in eG1-SCNT groups (12.7%) per recipient cow was higher than that in G0-SCNT groups (3%) (P < 0.05). The mean birth weight of cloned calves and the average calving score in the G0-SCNT groups (48.1 ± 3.4 kg and 3.3 ± 0.3, respectively) was significantly higher (P < 0.05) than those of eG1-SCNT groups (37.2 ± 2.1 kg and 2.3 ± 0.2, respectively). Results of this study indicate that synchronization of donor cells in eG1-phase using the shake-off method improved the overall production efficiency of the clone offspring per transferred embryo.
authors.affiliation: National Livestock Breeding Center, Ohu Station, Shichinohe, Aomori, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Goto
authors.forename: Muneyuki
authors.initials: M
authors.lastname: Hirayama
authors.forename: Kazuya
authors.initials: K
authors.lastname: Takeda
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Tukamoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Sakata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaeriyama
authors.forename: Masaya
authors.initials: M
authors.lastname: Geshi
mesh_terms: D000818:Animals; D001724:Birth Weight; D002417:Cattle / Q000502:physiology*; D005260:Female; D016193:G1 Phase; D053652:Nuclear Transfer Techniques / Q000662:veterinary*
keywords: bovine; cell cycle; nuclear transfer; shake-off