BACKGROUND This study investigated the effect of two in vitro embryo culture systems (co-culture system versus cell-free sequential-media) on developmental competence, cryosurvival and DNA- fragmentation of in vitro developed bovine blastocysts. MATERIALS AND METHODS Bovine presumptive zygotes were cultured in Ménézo's B2 (B2) plus vero-cells or sequential synthetic oviductal fluid (SOF) for ...

Reprogramming incompletely occurs in most somatic cell nuclear transfer (SCNT) embryos, which results in misregulation of developmentally important genes and subsequent embryonic malfunction and lethality. Here we examined transcriptome profiles in single bovine blastocysts derived by in vitro fertilization (IVF) and SCNT. Different types of donor cells, cumulus cell and ear-skin fibroblast, we...

Mouse blastocysts were exposed in vitro to various concentrations of N-methyl-N-nitrosourea and 3-methylcholanthrene. The incorporation of [3H]thymidine, [3H]uridine, and [3H]leucine into the exposed blastocysts was determined either immediately following exposure or after 18 hr of culture. The concentrations of N-methyl-N-nitrosourea or 3-methylcholanthrene used had no effect on blastocyst via...

BACKGROUND Ginkgolide B, the major active component of Ginkgo biloba extracts, can both stimulate and inhibit apoptotic signalling. We previously showed that ginkgolide treatment of mouse blastocysts induces apoptosis, decreases cell numbers, retards early post-implantation blastocyst development and increases early-stage blastocyst death. Here, we report more detailed examinations of the cytot...

The source and nature of zona lytic factors during zona escape of hamster blastocyts were investigated. When cultured in hamster embryo culture medium (HECM)-2h, all 8-cell embryos (n = 135) developed to zona escaped-blastocysts with complete zona lysis. In addition, 2-cell embryos, when co-cultured with zona escaping-blastocysts (at a ratio of 1:10), exhibited zona lysis. Various other embryos...

This study compared the effect of using either CZB or TCM 199 media on both the development of 1-2 cell ovine embryos from superovulated ewes to the blastocyst stage (Experiment 1), and the hatching process of ovine blastocysts developed in vitro (Experiment 2). For the first 5 d, the CZB medium showed higher rates of embryo development than the TCM 199 medium (p < 0.001). The embryos reaching ...

It is generally accepted that the hatching of mouse blastocysts is accompanied by regional dissolution of the zona pellucida by a trypsin-like proteinase synthesized in trophectoderm cells (Perona and Wassarman, 1986; Hogan et al., 1994), and trophectoderm cells protrude from the dissolved hole of the zona pellucida (Orsini and McLaren, 1967; McLaren, 1970; Niimura and Fujii, 1997). Then a slit...

OBJECTIVE To evaluate the effect of vitrification and two other methods of slow cryopreservation on DNA integrity in expanded and nonexpanded blastocysts. DESIGN Prospective in vitro study. SETTING Tertiary care academic hospital. INTERVENTION(S) 1) Twenty-two expanded blastocysts (EB) and 17 nonexpanded blastocysts (NEB) vitrified in cryotips; 2) 15 EB and 16 NEB by slow freezing using p...

Embryonic diapause (ED) is a temporary arrest of embryo development and is characterized by delayed implantation in the uterus. ED occurs in blastocysts of less than 2% of mammalian species, including the mouse (Mus musculus). If ED were an evolutionarily conserved phenomenon, then it should be inducible in blastocysts of normally non-diapausing mammals, such as domestic species. To prove this ...

OBJECTIVE To assess the effect of equilibration time on the DNA integrity of vitrified-warmed mouse blastocysts. DESIGN Prospective in vitro study. SETTING Embryology research laboratory. INTERVENTION(S) Mouse nonexpanded blastocysts (NEB) (n = 54) and expanded blastocysts (EB) (n = 56) were vitrified using cryotips. Blastocysts were vitrified using a two-step media protocol, with a first...