“…Sakkas and colleagues suggested that "abortive apoptosis" may be the cause since abnormal human spermatozoa presented some apoptotic-like features (Sakkas et al, 1999). Further investigation led to the demonstration that other biomarkers of apoptosis in sperm cells were present such as BCL-X, TP53, caspases, in addition to diverse structural defects (Baccetti et al, 1997;Donnelly et al, 2000;Gandini et al, 2000;Sakkas et al, 2002;Weng et al, 2002 Table 1. Summary of the single strand DNA repair pathways in mammalian cells (Ciccia and Elledge, 2010;Hoeijmakers, 2009;Martin et al, 2010;Mukherjee et al, 2010;Nouspikel, 2009;Robertson et al, 2009).…”