title: Single layer centrifugation-selected boar spermatozoa are capable of fertilization in vitro.
abstract: BACKGROUND
  Good quality spermatozoa are important to achieve fertilization, viable embryos and offspring. Single Layer Centrifugation (SLC) through a colloid (Androcoll-P) selects good quality spermatozoa. However, it has not been established previously whether porcine spermatozoa selected by this method maintain their fertility.
  
  
  METHODS
  The semen was prepared either by SLC or by standard centrifugation (control) and used for in vitro fertilization (IVF) at oocyte:spermatozoa ratios of 1:50; 1:100 and 1:300 (or 4 x 10(3), 8 x 10(3) and 24 x 10(3) spermatozoa/ml) to evaluate their subsequent ability to generate blastocysts. In addition, sperm motility was assessed by computer assisted sperm motility analysis.
  
  
  RESULTS
  Total and progressive motility were significantly higher in sperm samples prepared by SLC compared to uncentrifuged samples. Sperm binding ability, polyspermy, cleavage and blastocyst rates were affected by the oocyte:sperm ratio, but not by sperm treatment.
  
  
  CONCLUSIONS
  The use of SLC does not adversely affect the in vitro fertilizing and embryo-generating ability of the selected spermatozoa compared to their unselected counterparts, but further modifications in the IVF conditions would be needed to improve the monospermy in IVF systems. Since SLC did not appear to have a negative effect on sperm fertilizing ability, and may in fact select for spermatozoa with a greater potential for fertilization, an in vivo trial to determine the usefulness of this sperm preparation technique prior to artificial insemination is warranted.
authors.affiliation: Department of Clinical Sciences, Division of Reproduction, Swedish University of Agricultural Sciences, P.O. Box 7054, Uppsala, SE 750 07, Sweden. ylva.sjunnesson@slu.se
authors.forename: Ylva Cecilia Björnsdotter
authors.initials: YC
authors.lastname: Sjunnesson
authors.forename: Jane Margaret
authors.initials: JM
authors.lastname: Morrell
authors.forename: Raquel
authors.initials: R
authors.lastname: González
mesh_terms: D000818:Animals; D002498:Centrifugation / Q000379:methods / Q000662:veterinary*; D003102:Colloids; D005307:Fertilization in Vitro / Q000662:veterinary; D008297:Male; D055101:Semen Analysis / Q000662:veterinary; D013094:Spermatozoa / Q000502:physiology*; D013552:Swine / Q000502:physiology*
chemical_list: D003102:Colloids