Male infertility joins the translational medicine revolution. Sperm DNA: from basic science to clinical reality.

This issue of MHR contains six papers outlining and discussing the current state of our knowledge about male germ-cell DNA including the packaging of DNA during spermatogenesis and its unpacking in the oocyte, assessment of DNA damage in the male germ line and the consequences of this damage upon early embryo development and the subsequent generations. As is the nature of New Research Horizons review papers, the authors have been encouraged to be speculative, thought provoking, challenging whereas at the same time outlining future directions of travel. These reviews were invited as a result of an ESHRE Workshop (the meeting took place in the Karolinska Institute, Stockholm, Sweden, 21–22 May 2009) on ‘Sperm DNA: organisation, protection and vulnerability—from basic science to clinical application’. They represent an important benchmark for male reproductive health and will provide a platform for a clear and rapid improvement in our understanding of DNA in the male germ line and the effective translation of this knowledge into clinical practice. The assessment, origin, dynamics and consequences of damage to the paternal genome are receiving ever increasing attention. The importance of assessing DNA damage was highlighted following the demonstration of higher levels of chromatin damage in men with severe semen defects (Sun et al., 1997) and the potential negative impact of high levels of sperm DNA damage on both natural (Spanò et al., 2000) and ART conception (Larson et al., 2000). Subsequently, the field has seen a rapid expansion. In animals, where experiments can be performed to induce DNA damage to the paternal germ line, there have been clear and very strong associations between damage to the paternal genome, adverse effected embryo development and importantly subsequent negative effect on the new born and subsequent generation (Fernandez-Gonzalez et al., 2008). It is not the purpose of this editorial to reiterate what the individual authors discuss but three key themes are outlined below. Male infertility requires more robust diagnostic tools: DNA damage assays are likely to be the answer