title: In vitro fertilizing capacity of frozen-thawed bull spermatozoa selected by single-layer (glycidoxypropyltrimethoxysilane) silane-coated silica colloidal centrifugation.
abstract: Barriers to the use of density gradient centrifugation for preparing animal spermatozoa for artificial insemination (AI) include the scarcity of animal-specific formulations and the daunting prospect of processing large volumes of ejaculate in small aliquots (1.5 ml extended semen). Recently, new colloid formulations have been tested in vitro in a modified procedure, centrifugation on a single layer of colloid. The present study investigated the fertilizing ability during in vitro fertilization (IVF) of frozen-thawed bovine spermatozoa following centrifugation through a single layer of glycerolpropylsilane (GS)-coated silica colloid with a species-specific formulation (patent applied for; treatment, T). Controls (C) included centrifugation through gradients of either the same colloid (C1) or Percoll (C2). Sperm recovery surpassed 50% for both C1-C2 and T (n.s.). Mean values of various parameters of computerized analysis of sperm motility did not differ between T and C1 (n.s.), and only the proportions of path straightness and linearity were lower in T vs C2 (p < 0.05). In T, the mean (+/-SD) percentages of fertilization rate, blastocyst development rate and the total number of blastomeres were 58.1 +/- 23.3%, 24.5 +/- 14.3% and 94.6 +/- 23.4%, respectively. The proportions did not differ significantly from controls (C1/C2). Therefore, centrifugation through a single layer of colloid offers an alternative method to density gradient centrifugation for selection of viable, potentially fertile frozen-thawed bull spermatozoa. This single-layer technique is gentle, versatile and convenient because it facilitates scaling-up the process of sperm preparation to allow larger numbers of spermatozoa (for instance, whole ejaculates) to be processed for AI.
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Thys
authors.forename: L
authors.initials: L
authors.lastname: Vandaele
authors.forename: J M
authors.initials: JM
authors.lastname: Morrell
authors.forename: J
authors.initials: J
authors.lastname: Mestach
authors.forename: A
authors.initials: A
authors.lastname: Van Soom
authors.forename: M
authors.initials: M
authors.lastname: Hoogewijs
authors.forename: H
authors.initials: H
authors.lastname: Rodriguez-Martinez
mesh_terms: D000818:Animals; D002417:Cattle; D002469:Cell Separation / Q000379:methods / Q000662:veterinary*; D002499:Centrifugation, Density Gradient / Q000379:methods / Q000662:veterinary*; D003102:Colloids; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary*; D007202:Indicators and Reagents; D008297:Male; D011205:Povidone; D012821:Silanes; D012822:Silicon Dioxide; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology*
chemical_list: D003102:Colloids; D007202:Indicators and Reagents; D012821:Silanes; C016039:Percoll; D012822:Silicon Dioxide; D011205:Povidone