since its first clinical application in early 90s, preimplantation genetic diagnosis (pgd) has became a powerful diagnostic procedure in clinical practice for avoiding the birth of an affected child as well as increasing the assisted reproductive technologies (art) outcome . the technique involves the screening of preimplantation embryos for chromosomal abnormalities in certain indications such...

During mammalian embryonic development, abnormal eggs and embryos are eliminated by apoptosis; however, the precise apoptotic pathways remain as yet unidentified. In the present study, expression of Fas and Fas ligand - the proximal members of the death receptor pathway, was evaluated in mouse preimplantation embryos by immunofluorescence and in situ hybridization techniques. Ovulated oocytes w...

BACKGROUND & OBJECTIVE There are potential risks of major birth defect in IVF (in vitro fertilization) pregnancy as well as IVF-ICSI (intra cytoplasmic sperm injection) pregnancies in comparison with naturally conceived human pregnancies. This increase risk could be due to either gonadotropins used for ovarian stimulation or in vitro culture conditions or multiple pregnancy or combinations of a...

We have established a model that shows cooperative interaction among preimplantation embryos and the role of growth factors on their development and growth. Two-cell mouse embryos cultured singly in 25-microliters microdrops had inferior development to blastocysts and lower cell numbers per blastocyst compared with those cultured in groups of 5 or 10. The inferior development of singly cultured...

The ability of two embryonal carcinoma (EC) cell lines, F9 and PC13, to aggregate with preimplantation 8-cell mouse embryos is described. Both adhere to the embryonic cells and subsequently compact with the embryos. The aggregates form blastocysts in culture. The blastocysts sometimes contain the EC cells, located almost always in their inner cell mass. Differentiated derivatives of EC cells, n...

The aim of our study was to test the influence of short exposure (6 h) of preimplantation rabbit embryos to elevated temperatures (41.5 degrees C or 42.5 degrees C) in vitro on their developmental capacity. Fertilized eggs recovered from female oviducts at the pronuclear stage (19 hpc) were cultured at standard temperature (37.5 degrees C) until the morula stage (72 hpc). Afterwards, the embryo...

Gathering knowledge about the molecular events during preimplantation development is one of the most important challenges in in-vitro fertilization (IVF). The interleukin-1 (IL-1) system has been shown to be intimately involved in embryonic implantation. The aim of our study was to detect the major components of the IL-1 system in single blastomeres from human preimplantation embryos and to rel...

BACKGROUND/AIMS MicroRNA-29b (miR29b) has been previously identified in early mouse embryos through miRNA microarray analysis. Recent research has indicated that miR29b participates in DNA methylation by regulating DNA methyltransferase 3a/3b (Dnmt3a/3b) expression. However, the expression pattern and biological function of miR29b in mouse preimplantation embryonic development remain unknown. ...

In order to resolve the mechanisms and reasons of cellular fragmentation it is crucial to understand what genes may be responsible for regulation of this process. We report herein that human oocytes and preimplantation embryos possess abundant levels of transcripts encoding cell death suppressors, Mcl-1, Bcl-x and Bag-1, and the cell death inducer genes, Bax and Caspase-2. Lower but detectable ...

The role of membrane sterols in the compaction and subsequent development of the preimplantation mouse embryo was studied by incubating embryos in 7-ketocholesterol and other oxygenated sterols. These sterols have been shown to inhibit sterol synthesis and deplete membranes of cholesterol in a variety of ther cell types. Compaction and subsequent blastocyst formation were normal when embryos we...