BACKGROUND The present study was designed to investigate the expression of small-conductance calcium-activated K(+) channels 3 (SK3) in preimplantation embryos and to explore their role in the underlying mechanism of blastocyst hatching. METHODS Human preimplantation embryos were donated by patients who achieved successful pregnancy with in vitro fertilization. Mouse preimplantation embryos i...

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 ...

objective: 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...

BACKGROUND The aim of this study was to examine whether the integrity rate of pronuclei, after cryopreservation of pronuclear zygotes, could be a predictor of future embryo development and implantation. METHODS Two-pronuclei stage zygotes (n = 862) were cryopreserved by aseptic rapid freezing in 15% ethylene glycol + 15% DMSO + 0.2 M sucrose with a 4-step exposure in 12% (v:v), 25, 50 and 100...

In the present study, we propose an alternative technique called cytoplast fusion to improve the maturation rate and developmental competence of growing oocytes collected from early antral follicles in pigs. We examined whether the fusion of a growing oocyte with the cytoplast from a fully-grown oocyte (CFR group) could better promote maturation and developmental competence of the growing oocyt...

Background: Research studies on reproductive mechanism of laboratory animals are essential for further advancement of assisted reproductive techniques (ART). One of these studies includes the assessment of in-vitro development of pre-implantation embryos. The objective was to compare the cleavage rates and morphology of in-vivo formed 2 to 8 cell embryos and blastocysts with in-vitro culture of...

BACKGROUND Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known to promote the development and survival of human and mouse preimplantation embryos; however, the mechanism of action of GM-CSF in embryos is not defined. METHODS Mouse blastocysts were cultured from zygote stage in vitro with and without recombinant mouse GM-CSF (rmGM-CSF), and in vivo developed blastocysts were flu...

BACKGROUND Recently, human embryonic stem (hES) cells have become very important resources for basic research on cell replacement therapy and other medical applications. The purpose of this study was to test whether pluripotent hES cell lines could be successfully derived from frozen-thawed embryos that were destined to be discarded after 5 years in a routine human IVF-embryo transfer programme...

OBJECTIVE The aim of this study was to compare vitrification optimization of mouse embryos using electron microscopy (EM) grid, cryotop, and thin plastic strip (TPS) containers by evaluating developmental competence and apoptosis rates. METHODS Mouse embryos were obtained from superovulated mice. Mouse cleavage-stage, expanded, hatching-stage, and hatched-stage embryos were cryopreserved in E...

In this study we have examined the presence of mRNA encoding connexin 43 (Cx43) in bovine embryos derived in vivo and in vitro. Cumulus-oocyte complexes, immature and matured oocytes liberated from cumulus cells, zygotes, 2-4-cell and 8-16-cell embryos, morulae, blastocysts and hatched blastocysts were produced in vitro from ovaries obtained from an abattoir using TCM 199 supplemented with horm...