Significance of plasmalemma disruption in bovine and equine spermatozoa.
We have investigated fresh and cryopreserved bovine and equine spermatozoa using light and transmission soft X-ray microscopy. Spermatozoa were examined, in the presence or absence of semen, after using Percoll gradient centrifugation and re-suspending in medium. X-ray microscopy provided high resolution (30 nm) transmission images of whole cells in solution with high contrast, while retaining the simple preparation techniques used in light microscopy. We demonstrated translucent, membrane-bound vesicles in the acrosomal and midpiece regions that were similar in size and we noted their incidence in both fresh and frozen-thawed material from both animals. The vesicles were formed by the separation and expansion of the plasmalemma away from the underlying structure but were not caused by the freeze-thaw process. We suggest that these structures form part of the normal ultrastructure of spermatozoa and are damaged during preparation of the samples for transmission electron microscopy, resulting in a structure previously and incorrectly identified as damaged by the freezing and thawing process.
Abraham-Peskir
J V
JV
Institute for Storage Ring Facilities, University of Aarhus, Denmark. jabraham@ifa.au.dk
Chantler
E
E
Uggerhøj
E
E
D000177:Acrosome / Q000648:ultrastructure; D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000648:ultrastructure*; D002499:Centrifugation, Density Gradient; D015925:Cryopreservation; D006736:Horses; D008297:Male; D008853:Microscopy; D008854:Microscopy, Electron; D012662:Semen Preservation; D013094:Spermatozoa / Q000502:physiology* / Q000648:ultrastructure*; D014965:X-Rays