The developmental competence of in vitro cultured (IVC) embryos is markedly lower than that of their in vivo counterparts, suggesting the need for optimization of IVC protocols. Embryo culture medium is routinely replaced three days after initial culture in bovine, however, whether this protocol is superior to continuous nonrenewal culture method under current conditions remains unclear. Using ...

Concentrations of glycine (Gly) in embryo culture media are often lower (~0.1 mM) than those in oviductal or uterine fluids (≥1.2 mM). The objective of this study was to determine direct and osmolarity-dependent effects of physiological concentrations of Gly on blastocyst formation and hatching, cell allocation to the trophectoderm (TE) and inner cell mass (ICM), and metabolic activity of bovin...

BACKGROUND Vitrification has been shown as one of the most effective methods of cryopreservation for mammalian embryos. However, there is no consensus which stage of embryonic development is the most appropriate for vitrification with subsequent maximal development after thawing. This study was carried out to explore and compare the effect(s) of vitrification on mouse 2-cell, 4-cell, 8-cell, mo...

Glutamine and taurine are reported to be beneficial for mouse embryo development in vitro, and we have recently shown that glutamine improves human blastocyst formation in vitro. This randomized study compared the development of supernumerary human embryos in the presence of 1 mmol/l glutamine and/or 5 mmol/l taurine from the 2-4-cell stage to the blastocyst stage. Blastocyst development and ce...

Retinoids are recognized as important regulators of vertebrate development, cell differentiation, and tissue function. Previous studies, performed both in vivo and in vitro, indicate that retinoids influence several reproductive events, including follicular development, oocyte maturation and early embryonic development. The present study evaluated in vitro effects of retinol addition to media c...

Background: Fibroblast growth factors are a great family of growth factors that exert variety of functions in vertebrates including cell growth, survival, differentiation and migration. FGFRs are transmembrane tyrosine kinase receptors transmitting FGF signals. Four types of FGFRs (1/2/3/4) exist in vertebrates. FGF2 is one of the FGFs detected in bovine and ovine uterus flushes, supposing that...

Background: While assisted reproductive techniques (ARTs) are considered to be safe, many concerns exist about the safety of these techniques. Two important and indispensable parts of these techniques are in vitro culture and vitrification. While much progress has been made in developing culture conditions, it remains suboptimal. In order to investigate the effect of culture medium on in vitro ...

Interspecies somatic cell nuclear transfer (iSCNT) can be a solution for preservation of endangered species that have limited oocytes. It has been reported that blastocyst production by iSCNT is successful even if the genetic distances between donors and recipients are large. In particular, domestic pig oocytes can support the development of canine to porcine iSCNT embryos. Therefore, we examin...

Oct-4, the marker of pluripotent cells, is crucial for murine preimplantation development. During the formation of the blastocyst Oct-4 is downregulated in the trophectoderm (TE) and its expression becomes restricted to the inner cell mass (ICM). In order to determine the exact timing of the disappearance of Oct-4 protein from TE we analyzed the localization and level of Oct-4 at different stag...