Optimization of Ca2+ concentrations in fusion and activation media for production of cloned embryos from miniature pig somatic cells

• Published in: Journal of Reproduction and Development 2005, Vol.51(6), pp.699-706
• Main Authors: Miyoshi, K.(Kagoshima Univ. (Japan). Faculty of Agriculture), Yuki, Y, Yoshida, M
• Format: Article
• Language: English
• Subjects: Animals; Blastocyst - cytology; Ca2; CALCIO; CALCIUM; Calcium - pharmacology; Cell Fusion - methods; CELLS; Cells, Cultured; CELLULE; CELULAS; CERDO; Cloning, Organism - methods; CULTIVO IN VITRO; CULTURE IN VITRO; Cytochalasin B - pharmacology; DESARROLLO EMBRIONARIO; DEVELOPPEMENT EMBRYONNAIRE; Electric Stimulation; Embryo development; EMBRYONIC DEVELOPMENT; Female; IN VITRO CULTURE; ION; IONES; IONS; Miniature pig; NOYAU CELLULAIRE; Nuclear transfer; NUCLEO; NUCLEUS; Oocyte activation; Oocytes - drug effects; Oocytes - physiology; OVA; OVULE; OVULO; Parthenogenesis; PORCIN; REPIQUAGE; SWINE; Swine, Miniature; TRANSPLANTING; TRASPLANTE
• ISSN: 0916-8818; 1348-4400
• DOI: 10.1262/jrd.17023

The effects of Ca2+ concentration in activation medium and cytochalasin B treatment after activation on the parthenogenetic development of pig oocytes were examined. In addition, cloned embryos derived from miniature pig somatic cells were activated under optimal conditions and the effects of Ca2+ in fusion medium on the development of embryos after activation was examined. When oocytes were activated in 0.1 mM Ca2+ and then treated with cytochalasin B, the blastocyst formation rate (28.6%) was significantly higher than those activated in 0-0.05) or 1.0 mM (11.0-18.3%). Treatment with cytochalasin B decreased the second polar body extrusion rate of activated oocytes. The presence or absence of Ca2+ in fusion medium did not affect the fusion rate of miniature pig somatic cells with recipient oocytes. A few cloned embryos developed to the blastocyst stage (2.7-9.0%) without an additional activation treatment. On the other hand, significantly more embryos developed to the blastocyst stage after activation treatment when they were fused in the absence (28.9%) of Ca2+ rather than the presence (16.5%) of it. These results show that the highest blastocyst formation rate for miniature pig cloned embryos is obtained when donor cells and recipient oocytes are fused in the absence of Ca2+ and then activated in 0.1 mM Ca2+ and treated with cytochalasin B.