Lack of an Association Between Sperm Head Abnormality and DNA Damage by Alkaline Comet Assay

Sperm DNA damage affects sperm function, compromising reproductive outcome in both natural and assisted reproduction. The present study addresses the existing ambiguity between sperm morphology and DNA damage, by use of comet assay/single cell gel electrophoresis. Using comet assay as an end point, sperm DNA fragmentation in a total of 17 control and infertile subjects presenting to the infertility clinic of Kasturba Medical College has been investigated. Percent tail DNA, tail length and olive tail moment were selected as a measure to compare the extent of DNA damage between the groups. No significant difference was observed between the control group with morphologically normal sperm and experimental group with abnormal sperm morphology with respect to head DNA, tail DNA, Olive tail moment or tail length by alkaline comet assay. The comet assay failed to demonstrate any positive association between sperm morphology and DNA damage. In view of accumulating evidence on the importance of sperm DNA integrity in fertilization and embryogenesis, refined techniques allowing sperm selection with intact sperm DNA or with minimal DNA damage for clinical use should be sought.