Liucai Sui

Effects of chemically defined medium on early development of porcine embryos derived from parthenogenetic activation and cloning.

The present study was to investigate if a completely chemically defined medium (PZM-4) could support the early development of porcine embryos derived from parthenogenetic activation (PA) and cloning (somatic cell nuclear transfer, SCNT), and to lay the foundation for determining the physiological roles of certain supplements in this medium. Porcine embryos derived from PA and SCNT were cultured in media: PZM-3 (a chemically semi-defined medium), PZM-4 (a fully defined medium), and PZM-5 (an undefined medium). Early embryo development was observed. We found that the three medium groups (PZM-3, PZM-4 and PZM-5) exhibited no significant differences in cleavage rates of PA embryos (p > 0.05), while the blastocyst rate in PZM-3 was significantly higher than in PZM-4 and PZM-5 (78.9% vs. 36.0% and 52.3%) (p < 0.05). Moreover, total cell number per blastocyst in PZM-3 was clearly higher than in PZM-5 but similar to that in PZM-4. As for SCNT embryos, no significant differences were observed for the cleavage rates or the blastocyst rates among the three groups (p > 0.05). However, total cell number per blastocyst in PZM-3 was notably higher than in PZM-5, but was similar to that in PZM-4. In conclusion, our results suggested that the completely chemically defined medium PZM-4 can be used to efficiently support the early development of porcine PA and SCNT embryos.

Effect of Epigallocatechin-3-Gallate on the In Vitro Developmental Potential of Porcine Oocytes and Embryos Obtained Parthenogenetically and By Somatic Cell Nuclear Transfer

The present study aimed to investigate the effects of epigallocatechin-3-gallate (EGCG) on the in vitro development of porcine oocytes, parthenogenetic activation embryos (PA), and somatic cell nuclear transfer (SCNT) embryos. In Experiment 1, 0 (control), 10, 30, and 50 μg/mL EGCG were added to in vitro maturation (IVM) medium to explore the effect of EGCG on IVM of pig oocytes. The matured oocytes were then used to produce PA and SCNT embryos. Either for nuclear maturation of oocytes or for the rates of cleavage and blastocyst of PA and SCNT embryos, no significant difference was found among all groups. However, the total cell number per cloned blastocyst was significantly lower in blastocysts derived from oocytes matured in 50 μg mL EGCG (P<0.05) as compared with the other groups. In Experiment 2, we cultured pig SCNT and PA embryos in medium containing various concentrations of EGCG to examine the effect of EGCG on preimplantation development. The cleavage and blastocyst rates and the total cell number per blastocyst did not significantly differ between PA and SCNT embryos among all groups. However, the reactive oxygen species level was significantly lower in the PA embryos cultured in 10 μg mL EGCG than the other groups (P<0.05). Our results suggest that high doses of EGCG in IVM are harmful to the oocytes as evidenced by the decreased quality of SCNT embryos, and EGCG has no beneficial effects on in vitro development of pig cloned embryos.

Blastomere removal from cleavage-stage mouse embryos alters placental function, which is associated with placental oxidative stress and inflammation

Blastomere biopsy is an essential technique in preimplantation genetic diagnosis (PGD), a screening test that can detect genetic abnormalities of embryos before their transfer into uterus. Our results showed that the weights of fetuses derived from biopsied embryos were lower than that of non-biopsied counterparts at E12.5, E15.5, and E18.5. The ratio of fetal/placental (F/P) weights in the biopsied group was significantly lower than that in the non-biopsied group at E18.5. At E18.5, the mRNAs for selected glucose transporters, system A amino acid transporters, system L amino acid transporters, and imprinted genes were downregulated in the placentae of biopsied group, and the GLUT1 and CAT3 protein levels were decreased too. More apoptotic cells were detected by TUNEL in the placentae of biopsied group. Placentae from biopsied embryos exhibited lower levels of SOD and GSH. Furthermore, the concentration of MDA increased in the placentae from biopsied group. The levels of IL1B, IL6, and TNFA also significantly increased in the placentae of biopsied group. This study suggested that placental function may be sensitive to blastomere biopsy procedures, and placental oxidative stress and inflammation associated with blastomere biopsy may be critical factors of abnormal placental function and further influence the fetal development.