During fertilization, the fusion of the spermatozoa with the oocytes causes the release of calcium from the oocyte endoplasmatic reticulum. This, in turn, triggers a series of calcium ion (Ca²⁺) oscillations, a process known as oocyte activation. The sperm-specific factor responsible for oocyte activation is phospholipase C zeta (PLCζ). Men undergoing intracytoplasmic sperm injection (ICSI) with their spermatozoa lacking PLCζ are incapable of generating Ca²⁺ oscillation, leading to fertilization failure. The immunofluorescence assay is the most used technique to assess the expression and localization of PLCζ and to diagnose patients with reduced/absent ability to activate the oocytes. In these patients, the use of assisted oocyte activation (AOA) technique can help to yield successful ICSI results and shorten the time of pregnancy. However, the production of a stable PLCζ recombinant protein represents a new powerful therapeutic approach to treating individuals with this condition. We aim to conduct a systematic review focusing on the expression, level, and localization of PLCζ, discussing the novel genetic mutation associated with its impairment. In addition, we highlight the benefits of AOA, looking at new and less invasive methods to diagnose and treat cases with PLCζ dysfunction.

Background: The sperm centrosome is a key organelle composed of two centrioles surrounded by pericentriolar material and is essential for sperm aster formation and first mitotic spindle formation after sperm entry into the oocyte, thereby supporting early embryonic development. Methods: This systematic review evaluated 83 publications published between 1986 and 2026 to provide an updated overview of the human sperm centrosome, including its structural organization, protein composition, role in reproductive success, and association with embryonic abnormalities. Results: The available evidence indicates that centrosome-associated proteins such as centrin, γ-tubulin, and pericentrin are critical for spindle assembly, microtubule nucleation, and centriole duplication, and that alterations in their expression or localization are associated with poor sperm quality and reduced fertilization potential. Centrosomal dysfunction has also been linked to fertilization failure despite intracytoplasmic sperm injection, abnormal embryo cleavage, and possible embryonic aneuploidy. Although diagnostic approaches have improved, targeted treatments remain limited. Conclusions: These findings highlight the clinical relevance of sperm centrosomal integrity and support the need for further research into its diagnostic and therapeutic implications.

During fertilization, the fusion of the spermatozoa with the oocytes causes the release of calcium from the oocyte endoplasmatic reticulum. This, in turn, triggers a series of calcium ion (Ca2+) oscillations, a process known as oocyte activation. The sperm-specific factor responsible for oocyte activation is phospholipase C zeta (PLCζ). Men undergoing intracytoplasmic sperm injection (ICSI) with their spermatozoa lacking PLCζ are incapable of generating Ca2+oscillation, leading to fertilization failure. The immunofluorescence assay is the most used technique to assess the expression and localization of PLCζ and to diagnose patients with reduced/absent ability to activate the oocytes. In these patients, the use of assisted oocyte activation (AOA) technique can help to yield successful ICSI results and shorten the time of pregnancy. However, the production of a stable PLCζ recombinant protein represents a new powerful therapeutic approach to treating individuals with this condition. We aim to conduct a systematic review focusing on the expression, level, and localization of PLCζ, discussing the novel genetic mutation associated with its impairment. In addition, we highlight the benefits of AOA, looking at new and less invasive methods to diagnose and treat cases with PLCζ dysfunction ability.