The osmolarities of media that are most effective for in vitro culture of mammalian oocytes and embryos are lower than that of oviductal fluid. Oocytes and embryos can survive the high physiological osmolarity in vivo perhaps owing to the presence of amino acids such as glycine, which serve as organic osmolytes in the female reproductive tract. In the present study, the effects of glycine on th...

We have investigated the mechanisms by which the epithelial apicolateral junctional complex (AJC) is generated during trophectoderm differentiation in the mouse blastocyst using molecular, structural and functional analyses. The mature AJC comprises an apical tight junction (TJ), responsible for intercellular sealing and blastocoel formation, and subjacent zonula adherens E-cadherin/catenin adh...

Early development of the mouse comprises a sequence of cell fate decisions in which cells are guided along a pathway of restricted potential and increasing specialisation. The first choice faced by cells of the embryo is whether to become trophectoderm (TE) or inner cell mass (ICM); TE is an extra-embryonic tissue which will form the embryonic portion of the placenta, whilst ICM gives rise to c...

Two-dimensional gel electrophoresis has allowed the detection of proteins characteristic of inner cell mass and trophectoderm in mouse blastocyst. Certain of the proteins characterizing trophectoderm copurify with intermediate filaments from trophectoderm and a trophoblastoma cell line. A monoclonal antibody prepared against proteins of these intermediate filaments labels a filament network in ...

Cytoplasts with diameters of 40-45, 50-55 and 70-75 microm, derived from mouse oocytes at the germinal vesicle, metaphase II and zygote stages were incorporated into zygotes by electrofusion. Manipulated (n = 867) and culture-control (n = 1114) embryos were cultured in vitro and transferred to pseudo-pregnant recipients at the blastocyst stage. When synchronous cytoplasts measuring 40-45 and 50...

BACKGROUND Time-lapse imaging combined with embryo morphokinetics may offer a non-invasive means for improving embryo selection. Data from clinics worldwide are necessary to compare and ultimately develop embryo classifications models using kinetic data. The primary objective of this study was to determine if there were kinetic differences between embryos with limited potential and those more o...

BACKGROUND The conversion of retinol (ROH) to retinoic acid (RA) is crucial during development but has been not studied during blastocyst formation. METHODS AND RESULTS In vitro-produced bovine morulae were treated for 24 h with citral (which inhibits the synthesis of RA from ROH), citral + all trans retinoic acid (ATRA), ATRA or no additives. Citral interfered with blastocyst development, wh...

The purpose of this study was to determine whether dithiothreitol (DTT) treatment of sperm and ethanol activation improve embryo production by intracytoplasmic sperm injection (ICSI). Further, we compared ICSI with standard in vitro fertilization (IVF) in oocytes obtained from cattle. We demonstrated that DTT reduced the disulfide bond in the bovine sperm head. Using oocytes obtained from a sla...

An assay to determine the mechanism of regulation of embryonal carcinoma cells by the blastocyst, which is based on a comparison of tumors produced when the cancer cells are cloned alone or after incorporation into blastocysts, was refined by labeling embryonal carcinoma cells with fluorescent microspheres and by following their fate after injection into the blastocysts. Through the use of the ...