Sperm double-strand DNA breaks in patients with normozoospermia and pathozoospermia.

The levels of double-strand DNA breaks as a severe disruption of genome integrity were studied using the neutral version of the comet assay in the sperm samples of the men of the Belarusian population with normozoospermia and pathozoospermia, including asthenozoospermia, oligozoospermia, oligoasthenozoospermia, and other combined forms of pathozoospermia. It was demonstrated that double-strand DNA breaks have a large proportion (about 44–50 % on average) of the total number of DNA damage (singleand double-strand breaks, alkaline-labile sites, etc.) analyzed with the alkaline version of the comet assay recommended by the World Health Organization. Higher levels of sperm double-strand DNA breaks were established in the pathozoospermia group and in asthenozoospermia subgroup compared to the normozoospermia group. It was also shown that the levels of double-strand breaks observed at pathozoospermia correspond to the mutagenic effect in vitro of high concentrations (10–30 μg/ml) of bleomycin sulfate that acts as a strong radiomimetic, which points to a significant disruption of the DNA integrity at pathozoospermia. In general, the data obtained demonstrate the usefulness of the sperm double-strand DNA break analysis for male infertility diagnostics.