Development and quality of porcine embryos in different culture system and embryo-producing methods

Abstract

SUMMARYIn this study, the developmental ability and cellular composition of porcine IVF, parthenote and somatic cell nuclear transfer (SCNT) embryos were evaluated following differentin vitroculture systems. Group 1, embryos were cultured in NCSU-23 with 5.55 mMD-glucose (NCSU+) until day 6 on 20% O2or 5% O2(Group 2). Group 3, embryos were cultured inD-glucose-free NCSU-23 (NCSU−) with 0.17 mM Na pyruvate/2.73 mM Na lactate for 58 h and subsequently cultured in NCSU+ until day 6 (NCSU −/+) on 20% O2or 5% O2(Group 4). IVF blastocysts did not differ significantly with O2concentrations, but differed significantly with major energy source (glucose and pyruvate/lactate). In Group 3 and 4 IVF blastocysts, the total cell number and apoptosis rates were not significantly different with different O2concentrations. Blastocyst rate, total cell number and apoptosis rate in Groups 3 and 4 parthenote embryos also were not significantly different. Parthenote and SCNT, under the same culture treatment, exhibited significant differences in blastocyst and apoptosis rates (47.5 ± 16.1 vs. 24.0 ± 4.0 and 4.9 ± 9.0 vs. 22.8 ± 23.3). Apoptosis-generating rate increased in the order parthenote, IVF and then SCNT. In conclusion,in vitrodevelopment of porcine embryos was not affected by O2concentrations but was affected by major energy source. Even so, the concentration of each major energy source and the timing of its inclusion in culture could accomplish relatively high embryonic development, the apoptosis rate stressed that more work still needs to be done in developing a better defined culture system that could support SCNT embryos equivalent toin vivopreimplantation porcine embryos.