title: Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa.
abstract: The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized.
authors: Department of Preventive Veterinary Medicine and Animal Reproduction, School of Agrarian Sciences and Veterinary Medicine, Universidade Estadual Paulista, Jaboticabal 14884-900, Brazil. leticiazoccolaro@yahoo.com.br
authors: Letícia Z
authors: LZ
authors: Oliveira
authors: Vera Fm
authors: VF
authors: Hossepian de Lima
authors: Marcelo A
authors: MA
authors: Levenhagen
authors: Ricarda M
authors: RM
authors: Santos
authors: Terezinha I
authors: TI
authors: Assumpção
authors: José O
authors: JO
authors: Jacomini
authors: André Fc
authors: AF
authors: Andrade
authors: Rubens P
authors: RP
authors: Arruda
authors: Marcelo E
authors: ME
authors: Beletti
mesh_terms: D000177:Acrosome / Q000473:pathology* / Q000648:ultrastructure; D000818:Animals; D002417:Cattle / Q000502:physiology*; D002462:Cell Membrane / Q000473:pathology* / Q000648:ultrastructure; D002469:Cell Separation / Q000662:veterinary; D002499:Centrifugation, Density Gradient / Q000662:veterinary; D015925:Cryopreservation / Q000662:veterinary; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D011205:Povidone / Q000009:adverse effects*; D012822:Silicon Dioxide / Q000009:adverse effects*; D013094:Spermatozoa / Q000473:pathology / Q000648:ultrastructure
chemical_list: C016039:Percoll; D012822:Silicon Dioxide; D011205:Povidone