Genomic changes in spermatozoa of the aging male.

Modern society is witnessing a widespread tendency to postpone parenthood due to a number of socioeconomic factors. This ever-increasing trend relates to both women and men and raises many concerns about the risks and consequences lying beneath the natural process of aging. The negative influence of the advanced maternal age has been thoroughly demonstrated, while the paternal age has attracted comparatively less attention. A problematic issue of defining whether advanced paternal age can be considered an independent risk factor, not only for a man's fertility but also for the offspring's health, is represented by the difficulty, linked to reproductive studies, in characterizing the impact of maternal and paternal age, separately. Researchers are now trying to overcome this obstacle by directly analyzing the male germ cell, and emerging data prove this sperm-specific approach to be a valid tool for providing novel insights on the effects of aging on the spermatozoa and, thus, on the reproductive outcome of an aging male. The purpose of this chapter is to summarize most of what is known about the relationship between male aging and changes in the spermatozoa, giving special focus on the events occurring with age at the genomic level.