In Vitro Action of Cobra Venom on Goat Spermatozoa Ultrastructure by Transmission and Scanning Electron Microscopy

Abstract

Goat spermatozoa were incubated in vitro in Tris-citrate buffer, pH 7.2, containing 0, 40, 80, or 160 mug of Naja haje venom/mL buffer for 4 hours. During incubation, the percentages of sperm motility were decreased, while percentages of dead spermatozoa were increased in a time and concentration-dependent manner. The effect of venom concentrations on the ultrastructure of incubated spermatozoa was examined hourly by scanning (SEM) and transmission (TEM) electron microscopy. SEM results showed plasma membrane wrinkling at heads of some spermatozoa after 2 h incubation with 40mug venom. Most spermatozoa suffered membrane wrinkling after 4 h incubation. However, incubation with 80 mug venom caused membrane fractures in most sperm heads after 1 h incubation. The extent and depth of these fractures were increased after 2-3 h incubation. After 4 h incubation, plasma membrane focal erosion of many spermatozoa heads was common. Incubation with 160 mg venom induced sperm head swollen plasma membranes after 1 h incubation. Ruptured and disintegrated membranes were seen after 2 h; lysis and removal of external surface of spermatozoa head plasma membranes were recorded after 3-4 h incubation. TEM indicated slightly swollen areas on the sperm head plasma membrane, but showed normal nuclei, acrosomes, and tail regions after 2 h incubation in 40 mug cobra venom. The swollen areas were accompanied by sperm head membrane disintegration as well as membrane irregularities and distortion of tail mitochondrial cristae after 3-4 h incubation. However, incubation with 80 mug venom showed focal areas of membrane lysis and discontinuity in the sperm heads and tails increasing with incubation time. Severe axoneme and tail longitudinal fiber degeneration and increased numbers of distorted mitochondrial cristae were also observed after 3-4 h incubation. Spermatozoa incubation with 160 mug venom increased severity of plasma membrane dissolution, disintegration, and rupture. Axoneme disorganization and tail longitudinal fiber fusion were seen after 1-2 h; complete deformation of the motility system was recorded after 3-4 h incubation. Nuclei were normal, but acrosomes were partially damaged, and distorted mitochondrial cristae were increased after 4 h incubation. The results indicated that cobra venom induced a concentration and time-dependent alterations on spermatozoa plasma membrane as well as obvious deformation on the motility system and tail mitochondria, which are responsible for sperm viability and fertilizing ability

Heads you win, tails you lose: filtration processing for the microscopical examination of sperm heads

“…A further advantage of the technique was that many sperm heads were oriented in the coronal plane, an orientation rarely observed following either centrifugation or matrix pre‐embedding. Ultrastructural preservation was good following 1% glutaraldehyde fixation, and of comparable quality to that achieved in other studies (Rahmy & Ayoub, ; Tsai et al ., ; Collodel et al ., ).…”

Buckling patterns of thin films on curved compliant substrates with applications to morphogenesis and three-dimensional micro-fabrication

“…The intriguing wrinkling-like ordered patterns observed in quite a few fruits, vegetables, animal skins, tissues, and cells, [29][30][31][32][33] may be related to mechanics-driven buckling process owing to the mismatched deformation between the shell/film (e.g. skin of fruit or membrane of cell) and the underlying curved core/ substrate (e.g.…”

Crotalus durissus sp. rattlesnake venom induces toxic injury in mouse sperm

“…is the phospholipase A 2 (PLA 2 ). Studies have shown that this ophidic enzyme induces damage in membrane of goat (Rahmy and Ayoub, 2002) and mouse spermatozoa (Escoffier et al, 2010). Therefore, it is plausible to suggest the increase of sperm with abnormal morphology could have been mediated by the PLA 2 .…”