Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Zoology

In vitro fertilization (IVF) is an experimental procedure, is one of the most commonly used, which the oocytes are cultured with the sperm in a dish in the laboratory and once fertilization has occurred, the resulting embryos develop for 3 to 5 days before being placed in the uterus, and for the first time this conception happened outside a woman's body, nine months later the first test- tube baby was born. Intra cytoplasmic sperm injection (ICSI), is different from IVF, which one sperm is placed inside the oocyte with a microscopic needle, rather than many sperm positioned close to the outside of the oocyte, and as in IVF once fertilization occurs, the resulting embryo is transferred to the woman{u2019}s uterus. The oocytes are denuded by enzymatic and mechanical treatment in order to be able to perform the injection. The nuclear maturity of the oocytes can be evaluated and only oocytes that have extruded the first polar body are injected. However, metaphase-II oocytes that have not yet reached cytoplasmic maturity cannot be recognized. The mechanical stripping of the cumulus cells using small pipette diameter may cause; (1) displacement of the polar body, (2) impair the microtubule frame and the actin filament organization, (3) break of the cellular bridge that connect the polar body to the oocyte leading to deformation and damage of the oocyte cytoskeleton impairing its ability to sustain correctpronuclear formation, (4) zona pellucid fraction and oocyte degeneration

Issued also as CD