Abstract

DNA DAMAGE IN SPERM DUE TO CRYOPRESERVATION – A STUDY IN RATS

K. Thyaga Raju*, K. Kamala and K. Divya

Abstract

Background: Evaluating cryoinjury of rat spermatozoa is crucial to improving the probability of fertilization. Methodology: The epididymal rat spermatozoa were subjected to 15, 30, 45 and 60 days freezing separately, and then determined the motility, count, viability, morphological changes and DNA intactness after thawing each sample. Results: The results of thawed samples showed that the cryopreservation has significant effect on decrease in sperm motility (P < 0.01) to more than 50% and increase in percentage of dead or membrane damaged sperm formation. Therefore the frozen and thawed samples had decreased count and viability of spermatozoa (P < 0.01). Genetic damage was determined by comet assay and was compared in fresh and frozen-thawed samples, there were significantly More DNA strand breaks after cryopreservation. Conclusion: Our research findings have suggest that cryopreservation makes rat spermatozoa susceptible to external and internal damage, in particular during cooling process.

Keywords: Comet assay, Count, Epididymis, Motility.