• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.181-189
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• 2008

The aim of this study was to evaluate the effects of $Ca^{2+}$, $HCO_3{^-}$ and BSA on the in vitro capacitation-associated protein tyrosine phosphorylation, hyperactivation and acrosome reaction in guinea pig sperm. Caudal epididymal sperm were incubated in four different groups: modified TALP (Tyrode's albumin lactate pyruvate) or TALP without one of the medium constituents ($Ca^{2+}$, $HCO_3{^-}$ and BSA). After incubation for the required time (0 h, 0.5 h, 1 h, 3 h, 5 h, and 7 h), sperm were removed for further experiment. The capacitation effect was assessed by CTC (Chlortetracycline) staining. Western blotting and indirect immunofluorescence were used to analyze the level and localization of tyrosine phosphorylation. The results showed that guinea pig sperm underwent a time-dependent increase in protein tyrosine phosphorylation during the in vitro capacitation and the percentage of protein tyrosine phosphorylated sperm increased from 36% to 92% from the beginning of incubation to 7 h incubation. Also, there was a shift in the site of phosphotyrosine-specific fluorescence from the head of sperm to both the head and the flagellum. Moreover, an absence of $Ca^{2+}$ or $HCO_3{^-}$ inhibited in vitro hyperactivation and acrosome reaction and decreased the phosphorylation of the proteins throughout the period of in vitro capacitation. However, an absence of BSA could not influence these processes if substituted by polyvinyl alcohol (PVA) in the medium.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.1005-1012
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• 1997

Fine structural changes of the germ cells during spermatogenesis in the goldeye rockfish, Sebastes thompson; were examined by means of the transmission and scanning electron microscopy. A spermatogonium has a large nucleus with a single nucleolus in the interphase. Primary spermatocytes are characterized by the formation of chromatin clumps and presence of the synaptonemal complex in the nucleus. The nucleoplasm of secondary spermatocytes is more condensed than that of primary spermatocytes, and the cytoplasm contains numerous mitochondria, endoplasmic reticulum and Golgi complex. The nuclei of spermatids in metamorphosis show sickle-like shape as the nucleoplasm becomes more condensed. In the cytoplasm of spermatids, the proacrosomal granules are not found at all. A spermatozoon consists of head, neck and tail. The acrosome is absent in the head. Four to five cytoplasmic collars are observed in the posterior portion of the head of spermatozoon. The well developed axonemal lateral fins are observed in the flagellum of spermatozoon.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.181-189
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• 2011

Cryopreservation protocols induce partially irreversible damage to mammalian sperm plasma membranes. Previous studies have indicated that adding cholesterol to the plasma membrane, as cholesterol-loaded-cyclodextrins, improves cryosurvival of sperm. Therefore, the purpose of this study was to determine if treating sperm of Markhoz bucks with cholesterol-loaded-cyclodextrins (CLC) (0, 0.75, 1.5, 2.25 and 3 mg/ml diluted $240{\times}10^6$ sperm/ml) in Tris-citric acid-glucose diluents with and without egg yolk (containing 5% glycerol) would improve the post-thaw sperm quality. The motion characteristics were evaluated with a Computer Assisted System Analyzer (CASA); acrosome integrity and vitality were measured with the triple-stain technique. Samples were recovered before and after freezing by means of putting straws into $37^{\circ}C$ water for 30 sec and then parameters were assessed. The results showed that the treatments significantly affected motility, progressive motility, recovery rate, curvilinear velocity, beat cross frequency, live sperm with reacted acrosome, live sperm with unreacted acrosome, dead sperm with reacted acrosorne, and dead sperm with unreacted acrosome during freezing (p<0.05). However; no significant differences were found for average path velocity, straight line velocity, amplitude of lateral head displacement, straightness and linearity (p>0.05). The best results were observed for extender containing 2.25 mg/ml ($240{\times}10^6$ sperm/ml) CLC supplemented with 2.6% egg yolk. In conclusion, the findings of this study indicate improved Markhoz sperm viability and motility following treatment in the presence of egg yolk.

• Development and Reproduction
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• v.5 no.1
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• pp.53-57
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• 2001

Sperm capacitation and acrosome reaction (AR) have been known to be Ca$^{2+}$-dependent events. Sperm capacitation accompanies with cholesterol efflux fiom plasma membrane, that eventually stimulates AR. However, whether the AR mediated by cholesterol efflux is Ca$^{2+}$ dependent has not been verified yet. Recently, methyl beta cyclodextrin (MBCD) was found to evoke AR by stimulating the cholesterol efflux fiom sperm membrane. In the present study, we examined the requirement of Ca$^{2+}$ in the MBCD-induced AR. During incubation of sperm in the bicarbonate buffered media MBCD increased AR in a dose-dependent manner regardless of the Ca$^{2+}$ presence. In the presence of low molar concentration of Ca$^{2+}$ (100 ${\mu}$M), MBCD-induced AR was slightly increased compared to Ca$^{2+}$-free condition. In the absence of Ca$^{2+}$ supplement, spontaneous AR was slightly increased during the incubation but inhibited by 100 ${\mu}$M EGTA. MBCD potentiated AR even the presence of EGTA. However, EGTA attenuated MBCD-induced AR, suagesting the functional involvement of intracellular Ca$^{2+}$ in the MBCD-induced AR. Taken together, it was suggested that cholesterol efflux from the sperm plasma membrane was sufficient for induction of AR even in the absence of extracellular Ca$^{2+}$and that a condition permissive for mobilization of intracellular Ca$^{2+}$ is important for MBCD-induced AR.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.3
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• pp.147-152
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• 2007

Spermiogenesis and mature spermatozoa of the Korean false minnow Pseudogobio esocinus (Cyprinidae) are described by means of scanning and transmission electron microscopy. Spermiogenesis is characterized by lateral development of the flagellum, absence of nuclear rotation, and eccentric nuclear fossa formation. The spermatozoa have a spherical head containing a nucleus with highly condensed chromatin and no acrosome. The nuclear fossa contains the proximal centriole and anterior part of the distal centriole. The midpiece is type A II and contains semi-fused mitochondria around the axoneme. However, the symmetrical distribution of 4 or more the mitochondria does not follow a general pattern of the cyprinid spermatozoa. Cytoplasmic vesicles in the midpiece are common in Cypriniformes and some of Siluriformes and Characiformes spermatozoa.

• Applied Microscopy
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• v.29 no.2
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• pp.241-253
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• 1999

Fertilization pattern of north temperate bats is known to be unique for their sperm storage in the female reproductive tract during hibernation (e.g. Korean greater horseshoe bats). They copulate in fall but their ejaculated spermatozoa survive until the next spring. In another words they can persist to survive during long hibernation under the cold condition $(8\sim13^{\circ}C)$ and are to be fertilized with the ovum ovulated in the next spring, so called delayed fertilization. The present study was designed to observe morphological and functional changes of spermatozoa plasma membrane of the bats, hamsters which are hibernators, and mice which are non-hibernators in the room and the cold (bat-hibernation) temperatures and to confirm influence of the temperature on spermatozoa; survival rate, acrosome reaction rate, protein distribution, $Na^+-K^+-ATPase$ activities and scanning electron microscopic histochemistry. Based on the experimental results obtained in the present study, there were no significant morphological and functional differences in the spermatozoa plasma membrane in both the room and cold (bat-hibernation) temperatures and such an absence of difference suggests that the spermatozoa plasma membrane might play a pertinent role as a protector for consistent fertilization during and after hibernation.