title: Short-term storage and swim-up selection do not affect the x/y ratio in equine spermatozoa.
abstract: The standard procedure of artificial insemination with fresh equine spermatozoa involves short-term storage (to 48 h at 5°C). This procedure is accompanied by a gradual loss of sperm viability. The aim of this study was to investigate whether the X/Y ratio of equine spermatozoa is affected by short-term storage and the swim-up procedure. We used a standard protocol, for short-term storage (0, 24 and 48 h at 5°C) of stallion semen diluted in the commercial extender EquiPro™ (Minitüb GmbH, Tiefenbach, Germany). After each set-up storage period, the motile fraction of sperm cells was selected by the swim-up method. The X/Y ratio was evaluated by fluorescence in situ hybridization (FISH) in the fresh, non-selected sperm, and in motile spermatozoa selected after each of the storage periods. Molecular probes for the equine chromosomes X and Y were used. The X/Y ratio in all sperm samples analysed in this study (fresh and stored) was not different from the theoretical 1 : 1 value. The incidence of chromosomally abnormal sperm cells in the fresh (0.28%) and motile (0.13%) sperm samples was not significantly different. The two approaches (sperm storage up to 48 h and the swim-up procedure) applied to this study did not affect the X/Y ratio in the motile fraction of equine spermatozoa. This finding does not conform to phenomena described for human and cattle. For this reason, the finding may imply species-related differences.
authors.affiliation: Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Poznan, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Orsztynowicz
authors.forename: P
authors.initials: P
authors.lastname: Pawlak
authors.forename: B
authors.initials: B
authors.lastname: Kociucka
authors.forename: S
authors.initials: S
authors.lastname: Mucha
authors.forename: J
authors.initials: J
authors.lastname: Klukowska-Rotzler
authors.forename: D
authors.initials: D
authors.lastname: Lechniak
mesh_terms: D000818:Animals; D002469:Cell Separation / Q000379:methods / Q000662:veterinary*; D006736:Horses; D017404:In Situ Hybridization, Fluorescence; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013076:Sperm Count / Q000662:veterinary; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology*