Evaluation of aneuploidy and DNA damage in human spermatozoa: applications in field studies

With the goal of incorporating measures of sperm nuclear integrity in an epidemiology study, semen samples from young Czech men were analysed for sperm aneuploidy and sperm chromatin structure in addition to routine measures of sperm production and quality. The exposure in question was to high seasonal air pollution containing reactive polyaromatic hydrocarbons potentially capable of affecting spermatogenesis and damaging sperm DNA. The sperm aneuploidy assay uses fluorescence in situ hybridization to label selected sperm chromosomes; as applied in this study, the sex chromosomes (X,Y) and chromosome 8 were targeted. The sperm chromatin structure assay detects sperm nuclei with increased susceptibility to denaturation, a feature that is associated with DNA damage. Logistically, these assays were relatively easy to incorporate into the study design. The aneuploidy assay provided information suggesting that exposure to high levels of air pollution may increase the risk of sperm aneuploidy and that it is important to control for exposure to cigarette smoke and/or alcohol in such studies. The sperm chromatin structure assay provided valuable baseline information about Czech semen donors and data suggestive of an adverse effect of smoking and air pollution on spermatozoa that merits further investigation.