Background: Complete deletion of the complete AZFc interval of the Y chromosome is the most common known genetic cause of human male infertility. Two partial AZFc deletions (gr/gr and b1/b3) that remove some copies of all AZFc genes have recently been identified in infertile and fertile populations, and an association study indicates that the resulting gene dose reduction represents a risk factor for spermatogenic failure. Methods: To determine the incidence of various partial AZFc deletions and their effect on fertility, we combined quantitative and qualitative analyses of the AZFc interval at the DAZ and CDY1 loci in 300 infertile men and 399 control men. Results: We detected 34 partial AZFc deletions (32 gr/gr deletions), arising from at least 19 independent deletion events, and found gr/gr deletion in 6% of infertile and 3.5% of control men (p.0.05). Our data provide evidence for two large AZFc inversion polymorphisms, and for relative hot and cold spots of unequal crossing over within the blocks of homology that mediate gr/gr deletion. Using SFVs (sequence family variants), we discriminate DAZ1/2, DAZ3/4, CDY1a (proximal), and CDY1b (distal) and define four types of DAZ-CDY1 gr/gr deletion. Conclusions:The only deletion type to show an association with infertility was DAZ3/4-CDY1a (p = 0.042), suggesting that most gr/gr deletions are neutral variants. We see a stronger association, however, between loss of the CDY1a SFV and infertility (p = 0.002). Thus, loss of this SFV through deletion or gene conversion could be a major risk factor for male infertility.

Beside cytotoxic drugs, other drugs can impact men's fertility through various mechanisms. Via the modification of the hypothalamic-pituitary-gonadal axis hormones or by non-hormonal mechanisms, drugs may directly and indirectly induce sexual dysfunction and spermatogenesis impairment and alteration of epididymal maturation. This systematic literature review summarizes existing data about the negative impact and associations of pharmacological treatments on male fertility (excluding cytotoxic drugs), with a view to making these data more readily available for medical staff. In most cases, these effects on spermatogenesis/sperm maturation/sexual function are reversible after the discontinuation of the drug. When a reprotoxic treatment cannot be stopped and/or when the impact on semen parameters/sperm DNA is potentially irreversible (Sulfasalazine Azathioprine, Mycophenolate mofetil and Methotrexate), the cryopreservation of spermatozoa before treatment must be proposed. Deleterious impacts on fertility of drugs with very good or good level of evidence (Testosterone, Sulfasalazine, Anabolic steroids, Cyproterone acetate, Opioids, Tramadol, GhRH analogues and Sartan) are developed.

We have recently demonstrated that heterochromatin HP1 proteins are aberrantly distributed in lymphocytes of patients with immunodeficiency, centromeric instability and facial dysmorphy (ICF) syndrome. The three HP1 proteins accumulate in one giant body over the 1qh and 16qh juxtacentromeric heterochromatins, which are hypomethylated in ICF. The presence of PML (promyelocytic leukaemia) protein within this body suggests it to be a giant PML nuclear body (PML-NB). The structural integrity of PML-NBs is of major importance for normal cell functioning. Nevertheless, the structural organisation and the functions of these nuclear bodies remain unclear. Here, we take advantage of the large size of the giant body to demonstrate that it contains a core of satellite DNA with proteins being organised in ordered concentric layers forming a sphere around it. We extend these results to normal PML-NBs and propose a model for the general organisation of these structures at the G2 phase. Moreover, based on the presence of satellite DNA and the proteins HP1, BRCA1, ATRX and DAXX within the PML-NBs, we propose that these structures have a specific function: the re-establishment of the condensed heterochromatic state on late-replicated satellite DNA. Our findings that chromatin-remodelling proteins fail to accumulate around satellite DNA in PML-deficient NB4 cells support a central role for PML protein in this cellular function.