Long Term Incubation Affects the DNA Integrity and Methylation of Mouse Spermatozoa

Background: The quality of the sperm is influenced by various laboratory factors. This study investigated the effects of long-term incubation at room temperature (RT) versus 37°c on sperm DNA methylation and integrity. Methods: Mouse sperm samples were divided in to 3 groups( fresh, incubated at RT and 37°c for 24 hours). sperm parameters were assessed according to WHO guidelines. DNA Fragmentation index (%DFI) was evaluated by SCSA. DNA methylation was analyzed by flow cytometry. Results: Progressive motility and viability were significantly higher after incubation at RT compared with 37° c (P<0.001 and P<0.01, respectively). %DFI after 24 hours at 37° c was significantly higher than that at fresh sample (P < 0.002). Extended incubation at 37°C for 24 hours significantly decreases DNA methylation level compared with fresh sample (P <0.05). Conclusion: After 24 hours’ incubation, sperm DNA methylation and Fragmentation were affected. This study indicates a better sperm quality when incubation is performed at RT.

کلیدواژه ها:

Sperm ، DNA Fragmentation ، Temperature ، DNA Methylation ، Flow Cytometry