title: Motile human normozoospermic and oligozoospermic semen samples show a difference in double-strand DNA break incidence.
abstract: BACKGROUND
  Among ICSI children de novo structural chromosome aberrations of male descent are increased. Misrepair of double-strand DNA breaks (DSBs) is a prerequisite for such aberrations to occur. To date, no absolute assessment of the number of DSBs in human sperm nuclei after gamete fusion has been described.
  
  
  METHODS
  Using man-mouse heterologous ICSI and gammaH2AX immunofluorescent staining, capable of detecting a single DSB, the number of lesions in ICSI selected sperm from normozoospermic men (n = 2) and oligozoospermic patients (n = 3) was quantified. A comparison with a subfertile male mouse model (n = 5) has been made. In addition, the fate of morphologically normal ejaculated immotile sperm after ICSI was examined.
  
  
  RESULTS
  A significant increase in the fraction of sperm cells bearing DSBs was found in oligozoospermic semen compared with that from normozoospermic men (P < 0.01). The majority of morphologically normal immotile human sperm showed excess gammaH2AX staining and nuclear disintegration. However, some had a non-deviant DSB pattern.
  
  
  CONCLUSIONS
  The increased fraction of DSB-positive sperm in both human and mouse oligozoospermic semen is adding to the surmise that semen from oligozoospermic patients has a reduced chromatin quality, causally related to reduced preimplantation embryo development. The use of ejaculated immotile sperm for in vitro reproduction is debatable due to sperm DNA degradation.
authors.affiliation: Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Alwin A H A
authors.initials: AA
authors.lastname: Derijck
authors.forename: Godfried W
authors.initials: GW
authors.lastname: van der Heijden
authors.forename: Liliana
authors.initials: L
authors.lastname: Ramos
authors.forename: Maud
authors.initials: M
authors.lastname: Giele
authors.forename: Jan A M
authors.initials: JA
authors.lastname: Kremer
authors.forename: Peter
authors.initials: P
authors.lastname: de Boer
mesh_terms: D000818:Animals; D002843:Chromatin / Q000737:chemistry / Q000648:ultrastructure; D042002:Chromatin Assembly and Disassembly; D004247:DNA / Q000032:analysis*; D053903:DNA Breaks, Double-Stranded; D053938:DNA Fragmentation; D047108:Embryonic Development; D006657:Histones / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D009845:Oligospermia / Q000235:genetics* / Q000473:pathology; D012661:Semen / Q000737:chemistry*; D020554:Sperm Injections, Intracytoplasmic; D013081:Sperm Motility / Q000235:genetics*
chemical_list: D002843:Chromatin; C468783:H2AX protein, human; D006657:Histones; D004247:DNA