The objective of this study was to examine the effects of colcemid treatment during oocyte in vitro maturation (IVM) and embryonic development after parthenogenetic activation (PA) and somatic-cell nucleus transfer (SCNT) in pigs. Immature oocytes were treated with colcemid from 0 to 22, 38 to 42, or 0 to 22 hr followed by 38 to 42 hr during IVM (designated as COL0-22, COL38-42, and COL0-22/38-42, respectively). The proportion of oocytes reaching the germinal vesicle (GV)/GV breakdown (GVBD) stage after 22 hr of IVM was higher in COL0-22 (98.4%) than in controls not exposed to colcemid (68.7%). The proportion of metaphase-II (MII) oocytes after 30 hr of IVM was higher in control (79.6%) than in COL0-22 oocytes (61.7%); overall nuclear progression to the MII stage was not influenced by colcemid treatment by the end of the IVM period (93.8, 86.7, 86.8, and 84.8% for control, COL0-22, COL38-42, and COL0-22/38-42, respectively). COL0-22 oocytes showed higher intra-oocyte glutathione content (1.7 vs. 1.0-1.3 pixels/oocyte) and increased blastocyst formation after PA (68.7% vs. 42.5-52.2%) and SCNT (39.4% vs. 16.3-28.6%) than control, COL38-42, and COL0-22/38-42 oocytes. Colcemid treatment for 0-22 and 0-22/38-42 hr of IVM also stimulated the expression of cyclin-dependent kinase 1 (CDK1), proliferating cell nuclear antigen (PCNA), and extracellular signal-regulated kinase 2 (ERK2) mRNAs. Our results thus demonstrate that the presence of colcemid during the early stage of IVM stimulates preimplantation development of PA and SCNT porcine embryos by improving the cytoplasmic microenvironment.
© 2015 Wiley Periodicals, Inc.