Mitochondrial DNA integrity and copy number in sperm from infertile men

Objective: To determine the integrity and copy number of mitochondrial DNA (mtDNA) in spermatozoa from infertile men. We also compared mtDNA integrity to nuclear DNA integrity. Design: Observational. Setting: Tertiary care center. Patient(s): Semen samples were collected from 57 men, whose wives were undergoing in vitro fertilization, including 24 men with normal semen parameters. Main Outcome Measure(s): Quantitative long polymerase chain reaction (PCR) and real-time PCR were used to measure mtDNA integrity and copy number in spermatozoa. We also measured nuclear DNA integrity of spermatozoa with flow cytometry after acridine orange staining. Result(S): A significant increase in mtDNA copy number and a decrease in mtDNA integrity were observed in the spermatozoa samples from patients with abnormal semen parameters compared to the patients with normal semen parameters. The integrity and copy number of mtDNA were significantly correlated with sperm count. Conclusion(s): Mitochondrial DNA quantity and quality may serve as useful diagnostic markers of sperm quality in infertile men. (Fertil Steril (R) 2008;90:2238-44. (C) 2008 by American Society for Reproductive Medicine.)