title: Use of two conventional staining methods to assess the acrosomal status of stallion spermatozoa.
abstract: BACKGROUND
  The acrosome is a highly specialised region of the spermatozoon that is essential for fertilisation. Defects or dysfunction of this structure have been associated with fertility problems in man and various domestic species including stallions. Current methods of evaluating the acrosome of stallion spermatozoa are time consuming and require specialised equipment, which is cost prohibitive to the average practitioner.
  
  
  OBJECTIVE
  To evaluate 2 conventional stains (Dip Quick and Spermac) and determine their usefulness in assessing acrosome integrity in stallions as compared with specific acrosomal labelling with a fluorescein-conjugated lectin - a method that has been validated for acrosome status evaluation in stallions.
  
  
  METHODS
  In vivo experimental design.
  
  
  METHODS
  Semen from 6 mature Miniature horse stallions of known fertility was collected on 5 separate occasions. To increase the number of reacted acrosomes, portions of each ejaculate were incubated with the calcium ionophore, A23187. Ejaculates were divided and semen samples were processed according to recommendations for fluorescein-conjugated peanut lectin, Pisum sativum agglutin, Dip Quick, and Spermac staining methods. Slides were evaluated independently by 2 separate investigators. Spermatozoa were classified as having intact, reacting, reacted or defective acrosomes.
  
  
  RESULTS
  All parameters obtained by both investigators, using all 3 staining methods were highly correlated (P<0.001). There was no statistical difference (P>0.05) between investigators or staining method for the percentages of intact or reacted acrosomes. However, there was a significant difference between investigators and staining methods for determining reacting acrosome percentages (P<0.05).
  
  
  CONCLUSIONS
  Dip Quick and Spermac stains are useful for determining intact vs. reacted acrosomes for stallion spermatozoa.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine University of Florida, Gainesville, USA.
authors.forename: E E
authors.initials: EE
authors.lastname: Runcan
authors.forename: M A
authors.initials: MA
authors.lastname: Pozor
authors.forename: G L
authors.initials: GL
authors.lastname: Zambrano
authors.forename: S
authors.initials: S
authors.lastname: Benson
authors.forename: M L
authors.initials: ML
authors.lastname: Macpherson
mesh_terms: D000177:Acrosome / Q000502:physiology*; D000818:Animals; D006736:Horses / Q000502:physiology*; D008297:Male; D055101:Semen Analysis / Q000662:veterinary*; D013194:Staining and Labeling / Q000379:methods / Q000662:veterinary*
keywords: Dip Quick; Spermac; acrosome; horse; semen; spermatozoa; stallion