OBJECTIVE To analyze the genetic composition of oocytes and embryos presenting abnormal fertilization. DESIGN Case report. SETTING In vitro fertilization unit of a university-affiliated hospital. PATIENT(S) A couple with unexplained infertility with abnormal fertilizations in nine failed IVF-intracytoplasmic sperm injection cycles characterized by the presence of embryos with only one pro...

The morphology of fertilization events has been related to successful implantation by subjective criteria (pronuclei score, pronuclei symmetry and position). This work first described these events by time-lapse technology and then compared the timings of fertilization events (second polar body extrusion, first and second pronuclei appearance, abuttal and fading) in implanted versus nonimplanted...

Asymmetric meiotic divisions in mammalian oocytes rely on the eccentric positioning of the spindle and the remodeling of the overlying cortex, resulting in the formation of small polar bodies. The mechanism of this cortical polarization, exemplified by the formation of a thick F-actin cap, is poorly understood. Cdc42 is a major player in cell polarization in many systems; however, the spatio-te...