title: Detection of apoptotic alterations in sperm in subfertile patients and their correlations with sperm quality.
abstract: BACKGROUND
  The aim of the present study was to define the effect of apoptosis on sperm quality and function.
  
  
  METHODS
  The apoptotic features in sperm were assessed in 60 subfertile subjects, using Annexin-V staining for phosphatidylserine (PS) externalization and Tdt-mediated dUTP nick end labelling (TUNEL) assay for DNA fragmentation.
  
  
  RESULTS
  On average, about 45% of the sperm were found to be apoptotic based on the results from Annexin-V staining, including both early (Annexin-V-positive, PI-negative) and late apoptosis (Annexin-V-positive, PI-positive). TUNEL-positive cells (median value 15%) significantly correlated to late apoptosis but not early apoptosis, indicating that DNA fragmentation only occurs at the later stage of sperm apoptosis. TUNEL-positive and late apoptotic cells (Annexin-V-positive, PI-positive) were found to be inversely correlated to sperm motility and vitality, and positively to abnormal sperm morphology. On the other hand, it is surprising to note that the apoptotic alterations in sperm positively correlated to sperm concentration or total sperm counts.
  
  
  CONCLUSIONS
  Overall results from this study support the abortive apoptosis theory; apoptosis in mature sperm is initiated during spermatogenesis, after which some cells earmarked for elimination via apoptosis may escape the removal mechanism and contribute to poor sperm quality.
authors: Department of Community, Occupational and Family Medicine, Faculty of Medicine, National University of Singapore, Republic of Singapore.
authors: Han-Ming
authors: HM
authors: Shen
authors: Jun
authors: J
authors: Dai
authors: Sin-Eng
authors: SE
authors: Chia
authors: Alvin
authors: A
authors: Lim
authors: Choon-Nam
authors: CN
authors: Ong
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D053938:DNA Fragmentation; D006801:Humans; D007248:Infertility, Male / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010718:Phosphatidylserines / Q000378:metabolism; D013076:Sperm Count; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000473:pathology / Q000502:physiology*
chemical_list: D010718:Phosphatidylserines