Effects that bovine sperm cryopreservation using two different extenders has on sperm membranes and chromatin.
The process of cryopreservation impairs sperm cell function, potentially leading to a reduction in fertility. The objectives of the present study were to evaluate the effects that cryopreservation using two different extenders has on sperm motility and mitochondrial function, as well as on the integrity of plasma membranes, acrosomal membranes and chromatin, using practical and objective techniques. The focus of the present study was to identify correlations between alterations in sperm membranes and sperm motility in cryopreserved bovine spermatozoa. Seven ejaculates were collected from eight Simmental bulls (n=56). After collection, semen volume and concentration were assessed for purposes of dilution. Sperm motility was evaluated subjectively and by computer-assisted semen analysis, morphological characteristics were evaluated by differential interference microscopy, the integrity of plasma and acrosomal membranes, as well as mitochondrial function, were determined using a combination of fluorescent probes containing fluorescein isothiocyanate-Pisum sativum agglutinin, propidium iodide or 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide. Chromatin integrity was evaluated using the acridine orange technique. The semen was subsequently divided into two aliquots and diluted with one of two extenders (Bioxcell or Botu-Bov), after which both were packaged in 0.5 mL straws and frozen using an automated system. Two straws of semen from each treatment were thawed, and the semen parameters were evaluated as described above. Cryopreservation of sperm reduced motility, damaging plasma and acrosomal membranes, as well as decreasing mitochondrial function. The Botu-Bov extender was more effective in preserving sperm motility and membrane integrity than was the Bioxcell extender.
Celeghini
Eneiva Carla Carvalho
EC
Laboratory of Semen Biotechnology and Andrology, Department of Animal Reproduction, Veterinary Medicine and Animal Science School, University of São Paulo (USP), Brazil.
de Arruda
Rubens Paes
RP
de Andrade
André Furugen Cesar
AF
Nascimento
Juliana
J
Raphael
Cláudia Fernandes
CF
Rodrigues
Paulo Henrique Mazza
PH
D000177:Acrosome / Q000502:physiology; D000818:Animals; D002417:Cattle / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D002843:Chromatin / Q000502:physiology; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000737:chemistry; D008297:Male; D008857:Microscopy, Interference / Q000662:veterinary; D008928:Mitochondria / Q000502:physiology; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility / Q000502:physiology; D013094:Spermatozoa / Q000502:physiology*; D018709:Statistics, Nonparametric
D002843:Chromatin; D003451:Cryoprotective Agents; D005456:Fluorescent Dyes