The purpose of this study was to assess the feasibility of polyester mesh culture for the in vitro production of bovine embryos. In vitro matured and fertilized bovine oocytes were cultured in the 217×217, 230×230 or 238×238 µm openings of polyethylene terephthalate (PET) mesh sections or in simple micro-drops (control) for 7 days in CR1aa medium supplemented with 5% calf serum either under 20% and 5% O2 tensions. There was no difference in embryo developmental rates between the culture groups in terms of cleavage, blastocyst formation (34.9-47.2%) and blastocyst expansion irrespective of O2 tension. In contrast, under 20% O2 tension blastocysts that developed in PET mesh with 217×217 µm opening had significantly higher numbers of total cells and trophectoderm (TE) cells than control embryos; however, the numbers of inner cell mass (ICM) cells did not differ. Under 5% O2 tension no difference was found among the culture groups in the numbers of total, ICM and TE cells in embryos. All three PET mesh products investigated in this study were proven to be effective to prevent embryo movement. The results demonstrate that bovine embryos can be cultured in PET mesh sections without negative side effects and suggest that embryo distance determined by the mesh affects embryo quality at atmospheric oxygen tension. PET mesh with 217×217 µm openings was found to be the most suitable for further application in time-lapse cinematography. This work was supported by the Research and Development Program for New Bio-industry Initiatives.
