title: Nuclear DNA fragmentation negatively affects zona binding competence of Y bearing mouse spermatozoa.
abstract: OBJECTIVE
  To investigate the influence of sperm DNA integrity on the zona binding ability of mouse spermatozoa in relation to their sex chromosomal constitution.
  
  
  METHODS
  In this prospective experimental study, the sperm DNA fragmentation was induced by exposing testicular area of Swiss Albino mice (Mus musculus) to different doses of γ-radiation (0, 2.5, 5.0 and 10.0 Gy). Sperm DNA fragmentation was quantified by single cell gel electrophoresis (comet assay). In vitro sperm zona binding assay was performed and the numbers of zona bound X and Y bearing spermatozoa were determined using fluorescence in situ hybridization (FISH).
  
  
  RESULTS
  The assessment of zona pellucida bound X and Y-bearing spermatozoa using fluorescence in situ hybridization has revealed a unique binding pattern. The number of zona bound Y-spermatozoa declined significantly (P < 0.01 to 0.0001) with increase in the DNA damage. The skewed binding pattern of X and Y-bearing sperm was strongly correlated with the extent of sperm DNA damage.
  
  
  CONCLUSIONS
  The zona pellucida may have a role in preventing DNA damaged mouse sperm binding especially towards Y-bearing sperm. However, the exact mechanism behind this observation needs to be elucidated further.
authors.affiliation: Division of Clinical Embryology, Department of Obstetrics & Gynecology, Kasturba Medical College, Manipal University, Manipal, 576 104, India.
authors.forename: Dayanidhi
authors.initials: D
authors.lastname: Kumar
authors.forename: Dinesh
authors.initials: D
authors.lastname: Upadhya
authors.forename: Shubhashree
authors.initials: S
authors.lastname: Uppangala
authors.forename: Sujit Raj
authors.initials: SR
authors.lastname: Salian
authors.forename: Guruprasad
authors.initials: G
authors.lastname: Kalthur
authors.forename: Satish Kumar
authors.initials: SK
authors.lastname: Adiga
mesh_terms: D000818:Animals; D002467:Cell Nucleus; D004249:DNA Damage / Q000235:genetics; D053938:DNA Fragmentation; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D051379:Mice; D013084:Sperm-Ovum Interactions / Q000235:genetics* / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology*; D014960:X Chromosome / Q000235:genetics; D014998:Y Chromosome / Q000235:genetics*; D015044:Zona Pellucida / Q000502:physiology