부산대학교 도서관

Contents The presence of apoptotic features in spermatozoa has been related to lower quality and functional impairment. Members of the poly- ADP-ribose polymerases ( PARP) familyare involved in both DNA repair and apoptosis, playing important roles in spermatogenesis. Poly- ADP-ribose polymerase can be cleaved by caspases, and the presence of its cleavage product ( cPARP) in spermatozoa has been related to chromatin remodelling during spermatogenesis and to the activation of apoptotic pathways. There are no reports on immunodetection of cPARP in ram spermatozoa; thus, we have tested a commercially available antibody for this purpose. cPARP was microscopically detected in the acrosomal ridge of some spermatozoa (indirect immunofluorescence). A preliminary study was carried out by flow cytometry (direct immunofluorescence, FITC). Ram semen was extended in TALP and incubated for 4 h with apoptosis inducers staurosporine (10 μ m) or betulinic acid (200 μ m). Both inducers and incubation caused a significant increase in cPARP spermatozoa (0 h, control: 21.4±3.3%, inducers: 44.3±1.4%; 4 h, control: 44.3±2.4%, inducers: 53.3±1.4%). In a second experiment, we compared the sperm fractions after density gradient separation (pellet and interface). The pellet yielded a slightly lower proportion of cPARP spermatozoa (28.5±1.2% vs 36.2±2.0% in the interface; p < 0.001), and a 12-h incubation increased cPARP similarly in both fractions (p < 0.001). cPARP seems to be an early marker of apoptosis in ram semen, although its presence in untreated samples was weakly related to worse quality (pellet/interface). We suggest to study the relationship of PARP and cPARP levels with between-male differences on sperm fertility. [ABSTRACT FROM AUTHOR]