ABSTRACT
Sex chromosome distribution and aneuploidy as well as germ cell degeneration were evaluated in meiotic and post-meiotic cells from an infertile XYY male. Sex chromosome distribution was assessed by multicolour fluorescence in situ hybridization on meiotic preparations. Post-meiotic cell aneuploidy was characterized by a method combining multicolour fluorescence in situ hybridization and immunocytochemistry using the proacrosin-specific monoclonal antibody (mAb 4D4). TUNEL assay was carried out on seminiferous tubules to evaluate germ cell degeneration. At the prophase stage of the first meiotic division, 63.64% of cells at the pachytene stage carried three sex chromosomes. The ratio of X-bearing to Y-bearing spermatids and spermatozoa differed significantly from 1 : 1 with an excess of Y-bearing spermatids and spermatozoa. The frequency of hyperhaploid XY spermatids was increased in the XYY male, as well as the incidence of YY, XY and disomic 18 ejaculated spermatozoa. A preferential elimination of germ cells by apoptosis occurred in spermatocytes I. The persistence of the extra Y chromosome during meiosis of an XYY male is associated with a high rate of spermatocyte I degeneration and a low rate of aneuploid spermatozoa.