Abstract
This study aimed to describe phospholipase C zeta (PLCζ) deficiency from patients who experienced oocyte fertilization failure following intracytoplasmic sperm injection (ICSI) and to investigate the relationship between sperm DNA fragmentation, chromatin decondensation, and PLCζ. A total of 135 patients participated in this study-65 fertile men and 70 infertile patients- and semen samples were obtained to analyze concentration, motility, and morphology. PLCζ protein levels were assessed by immunofluorescence and quantitative techniques, DNA fragmentation by TUNEL essay, and chromatin decondensation by aniline blue staining. The proportion of spermatozoa presenting PLCζ was significantly lower in infertile patients (18.41 ± 18.84%) compared to fertile controls (67.31 ± 13.79%) (p < 0.001). A significant decrease in PLCζ protein levels was observed in infertile patients compared to fertile controls, which was the same for localization patterns for each region (acrosomal, equatorial, and combination of these regions). Significant correlations were also observed between sperm parameters and PLCζ levels, DNA fragmentation, and chromatin decondensation. Furthermore, a statistically significant correlation was detected between the percentage of spermatozoa presenting PLCζ and DNA integrity (p < 0.001). In summary, DNA fragmentation and chromatin decondensation are associated with alterations in the localization patterns and reduced protein levels of PLCζ, which may contribute to total fertilization failure.