Relationship between phospholipase C-zeta, semen parameters, and chromatin status

The need for additional tests to complement basic sperm analysis in clinics is well appreciated. In this regard, a number of tests such as sperm DNA integrity test as a tool in diagnosis and treatment of infertility are suggested. But recent studies have focused on main sperm factors involved in oocyte activation such as phospholipase C-zeta (PLCζ) that initiate intracellular Ca²⁺ signaling and embryogenesis. Therefore, this study aimed to investigate the relationship between PLCζ, basic semen parameters, sperm DNA fragmentation (SDF), and protamine deficiency in men with normal (n=32) and abnormal (n=23) semen parameters. Unlike SDF and protamine deficiency, as negative factors related to fertility, the mean value of PLCζ as positive factor related to infertility was significantly lower in men with abnormal semen parameters compared to men with normal semen parameters. Significant correlations were also observed between sperm concentration, motility, and abnormal morphology with the percentage of PLCζ positive spermatozoa. In addition, logistic regression analysis revealed that sperm morphology is more predictive than sperm motility and concentration for PLCζ presence. In addition, a statistically significant negative relationship was observed between the percentage of PLCζ positive spermatozoa and SDF. These findings suggested during ICSI, selection of sperm based on morphology has a profound effect on its ability to induce oocyte activation based on the likelihood of PLCζ expression. Therefore, assessment of PLCζ as an index for fertilization potential of a semen sample in men with severe teratozoospermia may define individuals who are candidates for artificial oocyte activation (AOA) and may avoid failed fertilization post ICSI.