Ionic regulation of the plasma membrane potential of rainbow trout (<i>Salmo gairdneri</i>) spermatozoa: Role in the initiation of sperm motility

Gatti, Jean‐Luc; Billard, Roland; Christen, Richard

doi:10.1002/jcp.1041430320

Cited by 80 publications

(49 citation statements)

References 50 publications

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“…Evoking such a conductance by exposing sperm to glutamate would have the effect of hyperpolarizing the sperm and could thus contribute to the hyperpolarization-mediated activation of sperm. 52 Moreover, it is known that extracellular glutamate concentration rises in a proximal-distal manner in the epididymis, 53 as does sperm motility. 54 Accordingly, it is possible that glutamate-evoked EAAT5-mediated chloride fluxes may have a role in modifying sperm motility.…”

Section: Discussionmentioning

confidence: 99%

Expression of multiple glutamate transporter splice variants in the rodent testis

Lee¹,

Anderson²,

Barnett³

et al. 2010

Asian J Androl

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Glutamate is a regulated molecule in the mammalian testis. Extracellular regulation of glutamate in the body is determined largely by the expression of plasmalemmal glutamate transporters. We have examined by PCR, western blotting and immunocytochemistry the expression of a panel of sodium-dependent plasmalemmal glutamate transporters in the rat testis. Proteins examined included: glutamate aspartate transporter (GLAST), glutamate transporter 1 (GLT1), excitatory amino acid carrier 1 (EAAC1), excitatory amino acid transporter 4 (EAAT4) and EAAT5. We demonstrate that many of the glutamate transporters in the testis are alternately spliced. GLAST is present as exon-3-and exon-9-skipping forms. GLT1 was similarly present as the alternately spliced forms GLT1b and GLT1c, whereas the abundant brain form (GLT1a) was detectable only at the mRNA level. EAAT5 was also strongly expressed, whereas EAAC1 and EAAT4 were absent. These patterns of expression were compared with the patterns of endogenous glutamate localization and with patterns of D-aspartate accumulation, as assessed by immunocytochemistry. The presence of multiple glutamate transporters in the testis, including unusually spliced forms, suggests that glutamate homeostasis may be critical in this organ. The apparent presence of many of these transporters in the testis and sperm may indicate a need for glutamate transport by such cells.

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Section: Discussionmentioning

confidence: 99%

Expression of multiple glutamate transporter splice variants in the rodent testis

Lee¹,

Anderson²,

Barnett³

et al. 2010

Asian J Androl

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“…Carp sperm motility can be initiated in media with an external pH of 6.0 -9.0 [91,92]. On the other hand, the internal pH of the sperm is about 1 unit below the external pH [60,93].…”

Section: Effect Of Phmentioning

confidence: 99%

Tale of Fish Sperm and Factors Affecting Sperm Motility: A Review

Islam¹,

Akhter²

2012

ALS

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Motility is an important function of the male gamete, which allows sperm to actively reach and penetrate the female gamete in organisms with internal and external fertilization. Sexual activity of some fish is generally seasonal and fertilization is external. Sperm, once differentiated in the gonad, remain there completely quiescent until they are released into the external medium, which is either freshwater or sea water. Various parameters such as ion concentrations (K + , Na + , Ca 2+ ), osmotic pressure, pH, and temperature affect motility. In the present paper, we review the roles of these factors on sperm motility in the teleosts. Studying the effects of these factors on teleost sperm can help establish good activation and/or immobilizing media for improving either artificial fertilization or cryopreservation.

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“…In salmonids, motility initiation occurs with dilution in freshwater, specifically from a reduction in extracellular potassium that drives a membrane hyperpolarization and an increase in intracellular calcium ([Ca 2ϩ ] i ) (2)(3)(4)(5)(6). Changes in the concentrations of specific ions (Ca 2ϩ , K ϩ , and possibly Na ϩ and Cl Ϫ ) also have been linked to motility initiation in Atlantic croaker sperm (7).…”

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confidence: 99%

Motility initiation in herring sperm is regulated by reverse sodium-calcium exchange

Vines

Yoshida

Griffin

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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Sperm of the Pacific herring, Clupea pallasi, are unique in that they are immotile upon spawning in the environment. Herring sperm have evolved to remain motionless for up to several days after spawning, yet are still capable of fertilizing eggs. An egg chorion ligand termed ''sperm motility initiation factor'' (SMIF) induces motility in herring sperm and is required for fertilization. In this study, we show that SMIF induces calcium influx, sodium efflux, and a membrane depolarization in herring sperm. Sperm motility initiation by SMIF depended on decreased extracellular sodium (<350 mM) and could be induced in the absence of SMIF in very low sodium seawater. Motility initiation depended on > 1 mM extracellular calcium. Calcium influx caused by SMIF involved both the opening of voltage-gated calcium channels and reverse sodiumcalcium (Na ؉ ͞Ca 2؉ ) exchange. Membrane depolarization was slightly inhibited by a calcium channel blocker and markedly inhibited by a Na ؉ ͞Ca 2؉ exchange inhibitor. Sodium efflux caused by SMIF-initiated motility was observed when using both extracellular and intracellular sodium probes. A Na ؉ ͞Ca 2؉ exchange antigen was shown to be present on the surface of the sperm, primarily over the midpiece, by using an antibody to the canine Na ؉ ͞Ca 2؉ exchanger. This antibody recognized a 120-kDa protein that comigrated with the canine myocyte Na ؉ ͞Ca 2؉ exchanger. Sperm of Pacific herring are now shown to use reverse Na ؉ ͞Ca 2؉ exchange in motility initiation. This mechanism of regulation of motility initiation may have evolved for both maintenance of immotility after spawning as well as ligand-induced motility initiation.T eleost fish sperm are quiescent within the testes and seminal plasma before spawning, but most initiate motility after dilution into the external medium (freshwater or seawater for most species) in which spawning occurs (1). In salmonids, motility initiation occurs with dilution in freshwater, specifically from a reduction in extracellular potassium that drives a membrane hyperpolarization and an increase in intracellular calcium ([Ca 2ϩ ] i ) (2-6). Changes in the concentrations of specific ions (Ca 2ϩ , K ϩ , and possibly Na ϩ and Cl Ϫ ) also have been linked to motility initiation in Atlantic croaker sperm (7). A hyperpolarization of the sperm membrane also has been documented in carp sperm, reportedly linked to the opening of voltage-gated Ca 2ϩ channels and an increase in [Ca 2ϩ ] i (8). In other freshwater teleost sperm (goldfish, zebra fish), as well as in marine teleost sperm (puffer, flounder), motility is believed to occur as a result of nonspecific hypo-or hyperosmotic changes that drive changes in intracellular ion concentrations (5, 9, 10). Thus, in all systems studied to date, a membrane hyperpolarization leads to an increase in [Ca 2ϩ ] i and the initiation of motility.Although the stimulation of sperm motility in the vicinity of eggs has been reported in some teleost fish, only herring sperm have been shown to require an egg chorion-derived ligand for ...

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Ionic regulation of the plasma membrane potential of rainbow trout (Salmo gairdneri) spermatozoa: Role in the initiation of sperm motility

Cited by 80 publications

References 50 publications

Expression of multiple glutamate transporter splice variants in the rodent testis

Expression of multiple glutamate transporter splice variants in the rodent testis

Tale of Fish Sperm and Factors Affecting Sperm Motility: A Review

Motility initiation in herring sperm is regulated by reverse sodium-calcium exchange

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