In the mouse, embryo culture results in a characteristic phenotype of retarded embryo preimplantation development and reduced numbers of cells within embryos. The expression of TRP53 is central to the regulation of the cell's capacity to proliferate and survive. In this study we found that Trp53 mRNA is expressed throughout the preimplantation stage of development. Levels of TRP53 protein expre...

The distribution of 5'-nucleotidase activity in pre-implantation mouse embryos is studied by means of a cytochemical method adapted from Uusitalo & Karnovsky (1977). The enzyme activity is detected, from the 4-cell stage up to the morula stage, on discrete patches of the cell membrane between blastomeres. Appropriate controls show that this distribution is not a localization artifact due to sel...

In an attempt to enhance embryo development, we have co-cultured 1-cell OF1 mouse embryos on bovine kidney epithelia (Madine-Darby bovine kidney; MDBK) cells in a complex medium called complex mouse tubal fluid (cMTF; based on the energy substrate levels found in the mouse oviduct, containing non-essential amino acids, glutamine and EDTA). To determine the quality of the blastocysts obtained, w...

Somatic cell nuclear transfer (SCNT) is considered to be a critical tool for propagating valuable animals. To determine the productivity calves resulting from embryos derived with different culture media, enucleated oocytes matured in vitro were reconstructed with fetal fibroblasts, fused, and activated. The cloned embryos were cultured in modified synthetic oviduct fluid (mSOF) or a chemically...

Low viability of manipulated or in vitro cultured is caused primarily by the reduced cell number in the implanting blastocysts. In order to investigate the effect of implantation delay on embryo viability and cell number, mouse blastocysts were transferred into oviducts of day 0 pseudopregnant females. This type of transfer improved embryo survival rates, indicating that embryos retarded by in ...

The key role of chemokine receptor CXCR4 in the maintenance of stemness property of stem cells has been shown recently. The low level laser irradiation (LLLI) is being used currently in a wide variety of clinical cases as a therapeutic tool for wound healing, relieving pain and destroying tumor cells. The aim of this study was to evaluate the effect of LLLI mimicking low level laser therapy (LL...

STUDY QUESTION Does the human embryo growth rate affect the outcome of vitrified-warmed blastocyst transfer? SUMMARY ANSWER Following vitrification, the incidence of abnormal spindle morphology was increased and the implantation competence was decreased in growth-retarded embryos compared with normally developing embryos. WHAT IS KNOWN ALREADY Various types of spindle abnormality occur in h...

Tetraploid complementation is often used to produce mice from embryonic stem cells (ESCs) by injection of diploid (2n) ESCs into tetraploid (4n) blastocysts (ESC-derived mice). This method has also been adapted to mouse cloning and the derivation of mice from induced pluripotent stem (iPS) cells. However, the underlying mechanism(s) of the tetraploid complementation remains largely unclear. Whe...