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Makoto Okuno - One of the best experts on this subject based on the ideXlab platform.
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Regulation of salmonid fish Sperm Motility by osmotic shock-induced water influx across the plasma membrane
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2014Co-Authors: L. Takei, Chinatsu Mukai, Makoto OkunoAbstract:Abstract The Motility of salmonid fish Sperm is initiated by a decrease in the extracellular K + concentration. However, our previous studies revealed that salmonid fish Sperm Motility could be initiated in the presence of an inhibitory concentration of K + by drastic osmotic shock induced by suspension in a hypertonic glycerol solution and subsequent dilution in a hypotonic solution (glycerol-treatment). In the present study, we examined if an osmotic shock-induced water influx is involved in the regulation of salmonid fish Sperm Motility. HgCl 2 , a common inhibitor of aquaporins (AQPs), decreased the duration of salmonid fish Sperm Motility. Dilution of Sperm cells in a hypotonic solution increased the cellular volume, whereas HgCl 2 inhibited such an increase in cellular volume. Furthermore, the expression of AQP 1a and 10 in rainbow trout testes was confirmed. In contrast, HgCl 2 did not affect glycerol-treated Sperm Motility, indicating that AQPs are not involved in glycerol-treated Sperm Motility. We also explored the possibility of aquaporin-independent water influx in glycerol-treated Sperm by assessing the Sperm membrane permeability using propidium iodide. The plasma membrane of glycerol-treated Sperm was considerably permeabilized. The cellular volume was decreased in a hypertonic glycerol solution and increased upon subsequent hypoosmotic shock, indicating an AQP-independent water flux across the plasma membrane upon glycerol-treatment. Taken together, these results showed that water influx across the plasma membrane via AQP is crucial for the maintenance of salmonid fish Sperm Motility under normal conditions, whereas water influx by osmotic shock-induced membrane permeation is critical for the initiation of glycerol-treated Sperm Motility.
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transient ca2 mobilization caused by osmotic shock initiates salmonid fish Sperm Motility
The Journal of Experimental Biology, 2012Co-Authors: Gen L Takei, Chinatsu Mukai, Makoto OkunoAbstract:Salmonid fish Sperm Motility is known to be suppressed in millimolar concentrations of extracellular K(+), and dilution of K(+) upon spawning triggers cAMP-dependent signaling for Motility initiation. In a previous study, however, we demonstrated that suspending Sperm in a 10% glycerol solution and subsequent dilution into a low-osmotic solution induced Motility independently of extracellular K(+) and cAMP. In the present study, we further investigated the glycerol-induced Motility mechanism. We found that treatment with solutions consisting of organic or inorganic ions, as well as glycerol, induced Sperm Motility in an osmolarity-dependent manner. Elimination of intracellular Ca(2+) by BAPTA-AM significantly inhibited glycerol-treated Sperm Motility, whereas removal of extracellular Ca(2+) by EGTA did not. Monitoring intracellular Ca(2+), using fluo-4, revealed that intracellular Ca(2+) increased when Sperm were suspended in hypertonic solutions, and a subsequent dilution into a hypotonic solution led to a decrease in intracellular Ca(2+) concomitant with Motility initiation. In addition, upon dilution of Sperm into a hypertonic glycerol solution prior to demembranation, the Motility of demembranated Sperm was reactivated in the absence of cAMP. The Motility recovery suggests that completion of axonemal maturation occurred during exposure to a hypertonic environment. As a result, it is likely that glycerol treatment of Sperm undergoing hypertonic shock causes mobilization of intracellular Ca(2+) from the intracellular Ca(2+) store and also causes maturation of axonemal proteins for Motility initiation. The subsequent dilution into a hypotonic solution induces a decrease in intracellular Ca(2+) and flagellar movement. This novel mechanism of Sperm Motility initiation seems to act in a salvaging manner for the well-known K(+)-dependent pathway.
Akihiko Watanabe - One of the best experts on this subject based on the ideXlab platform.
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Sperm Motility initiating substance may be insufficient to induce forward Motility of Cynops ensicauda Sperm.
Molecular Reproduction and Development, 2017Co-Authors: Tae Sato, Misato Yokoe, Daisuke Endo, Masaya Morita, Fubito Toyama, Yuuki Kawamura, Yuni Nakauchi, Eriko Takayama-watanabe, Akihiko WatanabeAbstract:Sperm Motility-initiating substance (SMIS) is a key protein for internal fertilization of the newt, Cynops pyrrhogaster, and commonly enhances forward Sperm Motility in some amphibian species, including external fertilizers. SMIS action varies among different species in correlation with a species-specific reproductive environment. In the present study, we identified the gene of C. ensicauda SMIS (CeSMIS) and examined the mechanism of SMIS action with reference to that of the closely related Cynops species. The CeSMIS was identified by a 176-amino acid sequence including seven amino acids critical for the initiation of Sperm Motility. The amino acid sequence showed 91% homology to the whole sequence of C. pyrrhogaster SMIS (CpSMIS). By immunostaining with an anti-CpSMIS antibody, CeSMIS was shown to be localized in the outer layer of the egg jelly. A peptide presenting the active site of SMIS was observed to bind to the axial rod of the midpiece in C. ensicauda Sperm. The localization and binding patterns of CeSMIS were fundamentally similar to those of CpSMIS. However, the SMIS peptide did not induce forward Motility of C. ensicauda Sperm, although it induced a fast wave of the undulating membrane. Forward Sperm Motility was induced in the egg jelly extract containing CeSMIS. These results suggest that the mechanism of initiation of Sperm Motility is differentiated between C. ensicauda and C. pyrrhogaster.
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Sperm Motility initiation by egg jelly of the anuran discoglossus pictus may be mediated by Sperm Motility initiating substance of the internally fertilizing newt cynops pyrrhogaster
Zygote, 2012Co-Authors: Eriko Takayamawatanabe, C Campanella, Hideo Kubo, Akihiko WatanabeAbstract:The egg jelly of Discoglossus pictus contains Sperm Motility-activating activity, the molecular basis of which has not been studied. Discoglossus pictus Sperm initiated Motility immediately after immersion in egg-jelly extract, as well as after immersion in hyposmotic solution, which initiates Sperm Motility in the external fertilization of anuran amphibians. Sequential treatment of the D. pictus Sperm with these two solutions revealed the predominant effect of hyposmolality in initiation of Motility. The Motility initiation induced by jelly extract was suppressed by a monoclonal antibody (mAb) that is specific for the 34 kDa Sperm Motility-initiating substance (SMIS) in the egg jelly of the newt, Cynops pyrrhogaster. Immunoblotting using the anti-SMIS mAb revealed several antigenic proteins that included major ones with sizes of 18- and 34-kDa in D. pictus jelly extract. Scanning electron microscopic observation revealed that granules of jelly matrix, in which SMIS localizes and which have a critical role in the internal fertilization of C. pyrrhogaster, were not observed near the surface of the D. pictus egg jelly. These results suggest that Sperm Motility-activating activity in egg jelly of D. pictus may be mediated by SMIS homologous proteins that act through a mechanism that is partially different from that of C. pyrrhogaster.
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characteristics of Sperm Motility induced on the egg jelly in the internal fertilization of the newt cynops pyrrhogaster
Zoological Science, 2003Co-Authors: Toshihiko Watanabe, Akihiko Watanabe, Tokuko Itoh, Kazuo OnitakeAbstract:Abstract Most urodeles undergo internal fertilization and Sperm are directly inseminated onto the surface of egg-jelly. Feature of Sperm Motility induced on the egg-jelly was examined in the newt, Cynops pyrrhogaster. When Sperm were directly inseminated onto an egg-jelly, Sperm Motility was immediately induced on its surface. The egg-jelly of C. pyrrhogaster was composed of six sublayers that were added by turns in oviduct. When the eggs with various sets of the sublayers were obtained and Sperm were inseminated onto the egg-jelly, the immediate activity for the initiation of Sperm Motility was observed only on the outermost sublayer. Similarly, the immediate initiation of Sperm Motility was induced in the Sperm suspended in the extract of the egg-jelly (JE). The initiation of Sperm Motility was affected by the external pH, and the Motility was activated in the moving Sperm. A K+-channel antagonist, charybdotoxin (CTX), or a Ca2+-channel antagonist, gallopamil inhibited the initiation of Sperm Motility i...
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Substances for the Initiation of Sperm Motility in Egg-Jelly of the Japanese Newt, Cynops pyrrhogaster
Zoological Science, 1999Co-Authors: Masahiko Ukita, Akihiko Watanabe, Tokuko Itoh, Toshihiko Watanabe, Kazuo OnitakeAbstract:Abstract The initiation of Sperm Motility is regulated by certain factors, including a change of osmolality or ion concentration. The cue for the initiation of Sperm Motility is unique to species and suits the environment in which the fertilization occurs. In the newt, Cynops pyrrhogaster, eggs are fertilized in the cloaca of the female with Sperm stored in the Sperm reservoir. In this study, we investigated possible factors initiating Sperm Motility in this unique environment. Sperm of C. pyrrhogaster could be initiated to move by a decrease of osmolality. However, eggs were fertilized with dry Sperm and developed to four-cell stage embryos without immersion in solution. They continued to develop normally to the tail-bud stage when placed in Steinberg's salt solution after fertilization. These results indicate that Sperm Motility was initiated without the change of osmolality around Sperm. In egg-jelly extract, the activity for the initiation of Sperm Motility was strong and heat stable, but disappeared ...
Emily R A Cramer - One of the best experts on this subject based on the ideXlab platform.
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Sperm morphology Sperm Motility and paternity success in the bluethroat luscinia svecica
PLOS ONE, 2018Co-Authors: Camilla Lo Cascio Saetre, Even Stensrud, Arild Johnsen, Emily R A CramerAbstract:: Postcopulatory sexual selection may select for male primary sexual characteristics like Sperm morphology and Sperm Motility, through Sperm competition or cryptic female choice. However, how such characteristics influence male fertilization success remains poorly understood. In this study, we investigate possible correlations between Sperm characteristics and paternity success in the socially monogamous bluethroat (Luscinia svecica svecica), predicting that Sperm length and Sperm swimming speed is positively correlated with paternity success. In total, 25% (15/61) of broods contained extra-pair offspring and 10% (33/315) of the offspring were sired by extra-pair males. Paternity success did not correlate significantly with Sperm morphology or any aspects of Sperm Motility. Furthermore, Sperm morphology and Sperm Motility did not correlate significantly with male morphological characters that previously have been shown to be associated with paternity success. Thus, the Sperm characteristics investigated here do not appear to be strong predictors of paternity success in bluethroats.
Chinatsu Mukai - One of the best experts on this subject based on the ideXlab platform.
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Regulation of salmonid fish Sperm Motility by osmotic shock-induced water influx across the plasma membrane
Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2014Co-Authors: L. Takei, Chinatsu Mukai, Makoto OkunoAbstract:Abstract The Motility of salmonid fish Sperm is initiated by a decrease in the extracellular K + concentration. However, our previous studies revealed that salmonid fish Sperm Motility could be initiated in the presence of an inhibitory concentration of K + by drastic osmotic shock induced by suspension in a hypertonic glycerol solution and subsequent dilution in a hypotonic solution (glycerol-treatment). In the present study, we examined if an osmotic shock-induced water influx is involved in the regulation of salmonid fish Sperm Motility. HgCl 2 , a common inhibitor of aquaporins (AQPs), decreased the duration of salmonid fish Sperm Motility. Dilution of Sperm cells in a hypotonic solution increased the cellular volume, whereas HgCl 2 inhibited such an increase in cellular volume. Furthermore, the expression of AQP 1a and 10 in rainbow trout testes was confirmed. In contrast, HgCl 2 did not affect glycerol-treated Sperm Motility, indicating that AQPs are not involved in glycerol-treated Sperm Motility. We also explored the possibility of aquaporin-independent water influx in glycerol-treated Sperm by assessing the Sperm membrane permeability using propidium iodide. The plasma membrane of glycerol-treated Sperm was considerably permeabilized. The cellular volume was decreased in a hypertonic glycerol solution and increased upon subsequent hypoosmotic shock, indicating an AQP-independent water flux across the plasma membrane upon glycerol-treatment. Taken together, these results showed that water influx across the plasma membrane via AQP is crucial for the maintenance of salmonid fish Sperm Motility under normal conditions, whereas water influx by osmotic shock-induced membrane permeation is critical for the initiation of glycerol-treated Sperm Motility.
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transient ca2 mobilization caused by osmotic shock initiates salmonid fish Sperm Motility
The Journal of Experimental Biology, 2012Co-Authors: Gen L Takei, Chinatsu Mukai, Makoto OkunoAbstract:Salmonid fish Sperm Motility is known to be suppressed in millimolar concentrations of extracellular K(+), and dilution of K(+) upon spawning triggers cAMP-dependent signaling for Motility initiation. In a previous study, however, we demonstrated that suspending Sperm in a 10% glycerol solution and subsequent dilution into a low-osmotic solution induced Motility independently of extracellular K(+) and cAMP. In the present study, we further investigated the glycerol-induced Motility mechanism. We found that treatment with solutions consisting of organic or inorganic ions, as well as glycerol, induced Sperm Motility in an osmolarity-dependent manner. Elimination of intracellular Ca(2+) by BAPTA-AM significantly inhibited glycerol-treated Sperm Motility, whereas removal of extracellular Ca(2+) by EGTA did not. Monitoring intracellular Ca(2+), using fluo-4, revealed that intracellular Ca(2+) increased when Sperm were suspended in hypertonic solutions, and a subsequent dilution into a hypotonic solution led to a decrease in intracellular Ca(2+) concomitant with Motility initiation. In addition, upon dilution of Sperm into a hypertonic glycerol solution prior to demembranation, the Motility of demembranated Sperm was reactivated in the absence of cAMP. The Motility recovery suggests that completion of axonemal maturation occurred during exposure to a hypertonic environment. As a result, it is likely that glycerol treatment of Sperm undergoing hypertonic shock causes mobilization of intracellular Ca(2+) from the intracellular Ca(2+) store and also causes maturation of axonemal proteins for Motility initiation. The subsequent dilution into a hypotonic solution induces a decrease in intracellular Ca(2+) and flagellar movement. This novel mechanism of Sperm Motility initiation seems to act in a salvaging manner for the well-known K(+)-dependent pathway.
Jacky Cosson - One of the best experts on this subject based on the ideXlab platform.
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species specificity of Sperm Motility activation and chemotaxis a study on ascidian species
The Biological Bulletin, 2013Co-Authors: Manabu Yoshida, Jacky Cosson, Noburu Sensui, Yuki Hiradate, Masaaki MorisawaAbstract:Egg-derived Sperm-activating factors and attractants activate Sperm Motility and attract the Sperm, respectively. These phenomena constitute the first communication signaling between males and females in the process of fertilization in many animals and plants, and in many cases, these are species-specific events. Thus, Sperm Motility activation and chemotaxis may act as a safety process for the authentication between conspecific egg and Sperm, and help to prevent crossbreeding. Here, we examine species-specificity of Sperm Motility activation and chemotaxis in the ascidians belonging to the order Phlebobranchiata: Ciona intestinalis, Ciona savignyi, Phallusia mammillata, Phallusia nigra, and Ascidia sydneiensis. Cross-reactivity in both Motility activation and chemotaxis of Sperm was not observed between C. savignyi and P. mammillata, or between A. sydneiensis and Phallusia spp. However, there is a “one way” (no reciprocity) cross-reaction between P. mammillata and P. nigra in Sperm activation, and betwee...
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Sperm Motility in fishes ii effects of ions and osmolality a review
Cell Biology International, 2006Co-Authors: Sayyed Mohammad Hadi Alavi, Jacky CossonAbstract:Abstract The Spermatozoa of most fish species are immotile in the testis and seminal plasma. Therefore, Motility is induced after the Spermatozoa are released into the aqueous environment during natural reproduction or into the diluent during artificial reproduction. There are clear relationships between seminal plasma composition and osmolality and the duration of fish Sperm Motility. Various parameters such as ion concentrations (K+, Na+, and Ca2+), osmotic pressure, pH, temperature and dilution rate affect Motility. In the present paper, we review the roles of these ions on Sperm Motility in Salmonidae, Cyprinidae, Acipenseridae and marine fishes, and their relationship with seminal plasma composition. Results in the literature show that: 1. K+ is a key ion controlling Sperm Motility in Salmonidae and Acipenseridae in combination with osmotic pressure; this control is more simple in other fish species: Sperm Motility is prevented when the osmotic pressure is high (Cyprinidae) or low (marine fishes) compared to that of the seminal fluid. 2. Cations (mostly divalent, such as Ca2+) are antagonistic with the inhibitory effect of K+ on Sperm Motility. 3. In many species, Ca2+ influx and K+ or Na+ efflux through specific ionic channels change the membrane potential and eventually lead to an increase in cAMP concentration in the cell, which constitutes the initiation signal for Sperm Motility in Salmonidae. 4. Media that are hyper- and hypo-osmotic relative to seminal fluid trigger Sperm Motility in marine and freshwater fishes, respectively. 5. The Motility of fish Spermatozoa is controlled through their sensitivity to osmolality and ion concentrations. This phenomenon is related to ionic channel activities in the membrane and governs the Motility mechanisms of axonemes.
