Biological Systems Engineering


Date of this Version



Reproduction, Fertility and Development, 2014, 26, 943–953


U.S. Government Work


Between Days 10 and 12 of gestation, porcine embryos undergo a dramatic morphological change, known as elongation, with a corresponding increase in oestrogen production that triggers maternal recognition of pregnancy. Elongation deficiencies contribute to embryonic loss, but exact mechanisms of elongation are poorly understood due to the lack of an effective in vitro culture system. Our objective was to use alginate hydrogels as three-dimensional scaffolds that can mechanically support the in vitro development of preimplantation porcine embryos. White cross-bred gilts were bred at oestrus (Day 0) to Duroc boars and embryos were recovered on Days 9, 10 or 11 of gestation. Spherical embryos were randomly assigned to be encapsulated within double-layered 0.7% alginate beads or remain as non-encapsulated controls (ENC and CONT treatment groups, respectively) and were cultured for 96 h. Every 24 h, half the medium was replaced with fresh medium and an image of each embryo was recorded. At the termination of culture, embryo images were used to assess morphological changes and cell survival. 17b-Oestradiol levels were measured in the removed media by radioimmunoassay. Real-time polymerase chain reaction was used to analyse steroidogenic transcript expression at 96 h in ENC and CONT embryos, as well as in vivo-developed control embryos (i.e. spherical, ovoid and tubular). Although no differences in cell survival were observed, 32% (P