ABSTRACT
OBJECTIVE: To examine the relationship between sperm strict morphology and sperm chromatin integrity. DESIGN: Prospective study. SETTING: Infertility clinic. PATIENT(S): Eighty-seven consecutive semen samples from non-azoospermic men presenting for infertility evaluation and 6 samples from fertile donors. INTERVENTION(S): Assessment of standard semen parameters and sperm chromatin structure assay (SCSA) parameters (%DFI [DNA fragmentation index] and %HDS [high DNA stainability]). Evaluation of %HDS and %DFI after treatment with dithiothreitol (a thiol-reducing agent used to decondense sperm nuclei) was also undertaken. MAIN OUTCOME MEASURE(S): Relationship between sperm strict morphology defects and SCSA parameters (%DFI and %HDS). RESULT(S): We observed significant relationships between the percentage of normal sperm forms and both %HDS (r = -0.40) and sperm motility (r = 0.32). We also found significant relationships between sperm head defects and both %HDS (r = 0.40) and sperm concentration (r = -0.39). Sperm tail, midpiece, and neck defects were not significantly related to the SCSA parameters. Treatment of spermatozoa with dithiothreitol (to induce decondensation) resulted in a substantial increase in %HDS but no measurable change in %DFI. CONCLUSION(S): The observed relationship between sperm head defects and %HDS suggests that sperm head abnormalities may, in part, be due to incomplete sperm chromatin condensation.
Subject(s)
Chromatin/ultrastructure , DNA/analysis , Sperm Head/ultrastructure , Asthenozoospermia/pathology , Azoospermia/pathology , Chromatin/chemistry , DNA Damage , Dithiothreitol/pharmacology , Humans , Infertility, Male/pathology , Male , Oligospermia/pathology , Reference Values , Semen/cytology , Semen/physiology , Sperm Count , Sperm Head/drug effects , Sperm Head/pathology , Sperm Motility , Spermatozoa/physiologyABSTRACT
OBJECTIVE: To localize foci of single-stranded (ss) DNA in sperm nuclei of fertile and infertile men. DESIGN: Prospective, observational study. SETTING: University infertility clinic. PATIENT(S): Semen samples from 12 consecutive asthenoteratospermic men presenting for infertility evaluation and 5 consecutive fertile men presenting for vasectomy. INTERVENTION(S): Semen analysis, semen processing, and immunocytochemistry using an antibody targeting ssDNA. MAIN OUTCOME MEASURE(S): Sperm nuclear ssDNA immunostaining pattern in whole and processed semen samples. RESULT(S): Immunocytochemistry (using ssDNA antibody) demonstrated one of two sperm nuclear staining patterns: [1] faint punctated staining, and [2] diffuse nuclear staining. Infertile men had a higher proportion of spermatozoa exhibiting diffuse ssDNA staining than did fertile men (52 +/- 19 vs. 14 +/- 13, respectively). The proportion of spermatozoa exhibiting diffuse ssDNA staining was significantly higher in whole compared with processed semen. Positive (DNAse-treated nuclei) and negative controls (S1 nuclease-treated nuclei) were obtained to validate the specificity of the antibody. CONCLUSION(S): Human sperm nuclei generally exhibit discrete (presumably peripheral) foci of ssDNA. The data also show that infertile men have a higher proportion of sperm nuclei with diffuse areas of ssDNA than do fertile men, and suggest that spermatozoa with diffuse nuclear staining are abnormal.
