title: Understanding fertilization through intracytoplasmic sperm injection (ICSI).
abstract: Since the establishment of in vitro fertilization, it became evident that almost half of the couples failed to achieve fertilization and this phenomenon was attributed to a male gamete dysfunction. The adoption of assisted fertilization techniques particularly ICSI has been able to alleviate male factor infertility by granting the consistent ability of a viable spermatozoon to activate an oocyte. Single sperm injection, by pinpointing the beginning of fertilization, has been an invaluable tool in clarifying the different aspects of early fertilization and syngamy. However, even with ICSI some couples fail to fertilize due to ooplasmic dysmaturity in relation to the achieved nuclear maturation marked by the extrusion of the first polar body. More uncommon are cases where the spermatozoa partially or completely lack the specific oocyte activating factor. In this work, we review the most relevant aspects of fertilization and its failure through assisted reproductive technologies. Attempts at diagnosing and treating clinical fertilization failure are described.
authors.affiliation: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Queenie V
authors.initials: QV
authors.lastname: Neri
authors.affiliation: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Bora
authors.initials: B
authors.lastname: Lee
authors.affiliation: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Zev
authors.initials: Z
authors.lastname: Rosenwaks
authors.affiliation: Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Doha, Qatar.
authors.forename: Khaled
authors.initials: K
authors.lastname: Machaca
authors.affiliation: The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, NY, USA. Electronic address: gdpalerm@med.cornell.edu.
authors.forename: Gianpiero D
authors.initials: GD
authors.lastname: Palermo
mesh_terms: D002118:Calcium / Q000502:physiology; D005260:Female; D005306:Fertilization / Q000502:physiology*; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D008297:Male; D009865:Oocytes / Q000502:physiology; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000502:physiology
chemical_list: D002118:Calcium
keywords: Assisted oocyte activation; Calcium influx; Failed fertilization; ICSI; Oocyte activation; PLCζ; Sperm cytosolic factor