Effects of different post-activation conditions on the developmental competence of in vitro matured porcine oocytes

다국어 초록 (Multilingual Abstract)

The objective of this study was to establish the effect of post-activation treatment with cytoskeletal regulators of CB, CB+CHX, CB+DC, CB+6’DMAP on embryonic development of pig oocytes after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT). PA and SCNT embryos were produced by using in vitro matured pig oocytes and treated for 4 h after electric activation with cytochalasins B (7.5 μg/ml), CB+cycloheximide (10 μg/ml), CB+demecolcine (0.4 μg/ml), and CB+2mM 6-Dimethylaminopurine. Post-activation treatment of PA oocytes with CB, CB+CHX, CB+DC and CB+6’DMAP no significant differences were found in embryo cleavage (83.2～91.5%), mean cell number of blastocysts (40.6～ 42.3% cells/blastocyst) but significantly (P<0.05) differences blastocyst formation (28.6～36.4%). When PA oocytes were treated with CB, CB+CHX, CB+DC, CB+6’DMAP, blastocyst formation was significantly (P<0.05) improved by CB (36.6%) compared to CB+CHX (30.9%), CB+DC (28.6%) and CB+6’DMAP (35.2%). In SCNT, was not significantly (P<0.05) increased by post-activation treatment with CB+CHX (81.3%), CB+DC (83.9%) and CB+6’DMAP (90.0%) compared to CB (84.5%) on embryo cleavage, blastocyst formation (19.1%~23.6%) and blastocyst cell number (39.6～41.4% cells/blastocyst) also were not influenced. But increased tendency in CB+6’DMAP. In addition, we investigated survivin expression in porcine SCNT embryos during the early developmental stages. The levels of survivin mRNA in 2-4 cell stage SCNT embryos were significantly higher 6’DMAP treated group than other treatment groups of SCNT embryos. These observations suggested that 2-4 cell cleaving embryos at have high developmental competence, and which may be influenced by survivin expression in porcine SCNT embryos. Our results demonstrate that post-activation treatment with CB, CB+CHX, CB+DC, CB+6’DMAP improves pre-implantation development of SCNT embryos and the stimulating effect of cytoskeletal modifiers on embryonic development is differentially shown depending on the origin (PA or SCNT) of embryos in pigs.