Apoptotic markers in ejaculated human spermatozoa.
The role of male germ cell death in spermatogenesis is an important one as it removes dysfunctional or genetically damaged germ cells and is necessary to maintain an optimal germ cell to Sertoli cell ratio. The formation of the bloodtestis barrier requires the elimination of excessive germ cells and a surge of germ cell apoptosis occurs prior to puberty regulating the ratio of germ cells to Sertoli cells. The aim of this study was to evaluate the presence of four apoptotic markers on sperm from patients with various grades of fertility using flow cytometry. Furthermore, any correlations between the apoptotic marker assays and the standard semen analysis results were identified. This study compares early and late parameters of apoptosis with morphological features in spermatozoa in the same samples. The three sample groups were identified as: teratozoospermic [G-pattern] (n=26), teratozoospermic [P-pattern] (n=98) and oligoteratozoospermic [Ppattern] (n=36). Standard semen analysis was conducted on the semen samples according to the WHO guidelines. Four apoptotic marker assays using flow cytometry was applied in this study to examine the apoptotic alterations in ejaculate sperm. These assays included the Annexin-V staining for the determination of phosphatidylserine exposure, APO-Direct to identify DNA fragmentation, caspase-3 to detect expression of this active protease during early apoptosis and Fas expression. For the Annexin-V and caspase-3 assays, statistically significant differences (P<