Relationship between Developmental Ability and Cell Number of Day 2 Porcine Embryos Produced by Parthenogenesis or Somatic Cell Nuclear Transfer

Abstract

In vitro produced porcine embryos have potential application in reproductive biotechnology. However, their development potential has been very low. This study evaluated the in vitro developmental ability and quality of cloned and parthenogenetic porcine embryos having 2-4 cells or 5-8 cells on Day 2 of in vitro culture. Analysis of results showed that 2 to 4 cell embryos had higher ability to form blastocysts than 5 to 8 cell embryos (p<0.05). Blastocysts produced from culture of 2 to 4 cell embryos also contained higher cell numbers and had lower BAX:BCLxL transcript ratio than those produced from 5 to 8 cell embryos (p<0.05), thereby suggesting 2 to 4 cell embryos have higher development potential. Further investigation revealed that 5 to 8 cell embryos had higher incidence (100±0.0%) of blastomeric fragmentation than 2 to 4 cell embryos (15.2±5.5% for parthenogenetic and 27.7±7.1% for cloned embryos). This suggests that low development potential of 5 to 8 cell embryos was associated with blastomeric fragmentation. In conclusion, we have shown that morphological selection of embryos based on cell number on Day 2 of in vitro culture could offer a practical and valuable non-invasive means to select good quality porcine embryos.

Developmental arrest of scNT‐derived fetuses by disruption of the developing endometrial gland as a result of impaired trophoblast migration and invasiveness

“…scNT was performed as reported previously (Yin et al, 2003;Park et al, 2005;Chae et al, 2006Chae et al, , 2008Cho et al, 2007;Lee et al, 2007;Hwang et al, 2009;Park et al, 2009;Uhm et al, 2009). Briefly, matured eggs with a first polar body were cultured in medium supplemented with 0.05 mol/L sucrose for 1 hr.…”

“…Developing scNT-Derived Placenta Villi scNT was performed according to one of our established protocols (Yin et al, 2003;Park et al, 2005;Cho et al, 2007;Lee et al, 2007;Hwang et al, 2009;Park et al, 2009;Uhm et al, 2009). scNT eggs at the 1-to 4-cell stage were surgically transferred into the oviducts of the 11 synchronized recipient gilts.…”

Effects of Co‐culture of Cumulus Oocyte Complexes with Denuded Oocytes During In Vitro Maturation on the Developmental Competence of Cloned Bovine Embryos

“…One study showed that the total number of bovine SCNT embryos was lower than in the IVF embryos although there was no significant difference between the two groups . But another study reported that the total cell number of porcine SCNT blastocysts was significantly lower than in the parthenogenetic blastocysts (Uhm et al 2009). These results demonstrated that SCNT+DO embryos increased the blastocysts development, although no significant difference was found compared to control.…”

“…But another study reported that the total cell number of porcine SCNT blastocysts was significantly lower than in the parthenogenetic blastocysts (Uhm et al. ). These results demonstrated that SCNT+DO embryos increased the blastocysts development, although no significant difference was found compared to control.…”

Adiponectin Improves In Vitro Development of Cloned Porcine Embryos by Reducing Endoplasmic Reticulum Stress and Apoptosis

“…Inhibition of ER stress by alleviating the expression of active XBP1 improved embryo development in mice and pigs [ 29 , 60 , 61 ]. However, day-2 embryos with 5 to 8 cells can be associated with fragmented embryos [ 62 ]. Embryos derived from SCNT and parthenogenetic activation revealed a higher occurrence of fragmented embryos whose presence was misinterpreted during observation under a microscope [ 63 , 64 ].…”