Contribution of different Ca2+ channels to the acrosome reaction-mediated initiation of sperm motility in the newt Cynops pyrrhogaster

Zygote ◽  
2013 ◽  
Vol 23 (3) ◽  
pp. 342-351 ◽  
Author(s):  
Eriko Takayama-Watanabe ◽  
Hiroto Ochiai ◽  
Shunpei Tanino ◽  
Akihiko Watanabe
Keyword(s):  
Sperm Motility ◽  
Acrosome Reaction ◽  
Emission Spectrometry ◽  
Cynops Pyrrhogaster ◽  
Reliable Source ◽  
Voltage Dependent ◽  
Egg Jelly ◽  
High Level ◽  
Sequential Gating ◽  
Ca2 Channels

SummaryInitiation of sperm motility in urodeles, which is induced by a sperm motility-initiating substance (SMIS) in the sequestered granules on the surface of egg jelly, is mediated by the acrosome reaction (AR), which is triggered by an AR-inducing substance (ARIS) on a sheet-like structure. Details of the unique process of the interaction between egg jelly and sperm in these species is still unclear. The current study showed the fine structure of egg jelly in the newt Cynops pyrrhogaster, a urodele species, revealing that its outer surface was covered by a sheet-like structure of approximately 0.29 μm in thickness. Granules of approximately 2 μm in diameter with small particles of approximately 54 nm were attached to its surface and distributed inhomogeneously just beneath the sheet-like structure. Emission spectrometry revealed that the Ca2+ concentration was maintained at a high level compared with that of the blood plasma and the vas deferens fluid, suggesting that egg jelly is a reliable source of Ca2+ for the sperm–egg interaction. Blockers of the T-type voltage-dependent Ca2+ channel (VDCC), but not the L-type VDCC, inhibited both AR and initiation of sperm motility. Conversely, Ni+, which affects the α1 H subunit of T-type VDCC, only inhibited the initiation of sperm motility. These data suggest that, in response to ARIS and SMIS, sequential gating of distinct Ca2+ channels occurs in the AR, followed by the initiation of sperm motility on the surface of the egg jelly in C. pyrrhogaster at fertilization.

Identification of egg-jelly substances triggering sperm acrosome reaction in the newt,Cynops pyrrhogaster

2009 ◽  
Vol 76 (4) ◽  
pp. 399-406 ◽  
Author(s):  
Akihiko Watanabe ◽  
Keiko Fukutomi ◽  
Hideo Kubo ◽  
Manami Ohta ◽  
Eriko Takayama-Watanabe ◽  
...  
Keyword(s):  
Acrosome Reaction ◽  
Cynops Pyrrhogaster ◽  
Egg Jelly ◽  
Sperm Acrosome Reaction ◽  
Sperm Acrosome

scholarly journals Ca2+ channels from the sea urchin sperm plasma membrane.

1990 ◽  
Vol 95 (2) ◽  
pp. 273-296 ◽  
Author(s):  
A Liévano ◽  
E C Vega-SaenzdeMiera ◽  
A Darszon
Keyword(s):  
Plasma Membrane ◽  
Sea Urchin ◽  
Acrosome Reaction ◽  
Main Channel ◽  
Open Probability ◽  
Boltzmann Function ◽  
Sperm Plasma Membrane ◽  
Egg Jelly ◽  
Sea Urchin Sperm ◽  
Ca2 Channels

Ca2+ influx across the sea urchin sperm plasma membrane is a necessary step during the egg jelly-induced acrosome reaction. There is pharmacological evidence for the involvement of Ca2+ channels in this influx, but their presence has not been directly demonstrated because of the small size of this cell. Sea urchin sperm Ca2+ channels are being studied by fusing isolated plasma membranes into planar lipid bilayers. With this strategy, a Ca2+ channel has been detected with the following characteristics: (a) the channel exhibits a high mainstate conductance (gamma MS) of 172 pS in 50 mM CaCl2 solutions with voltage-dependent decaying to smaller conductance states at negative Em; (b) the channel is blocked by millimolar concentrations of Cd2+, Co2+, and La3+, which also inhibit the egg jelly-induced acrosome reaction; (c) the gamma MS conductance sequence for the tested divalent cations is the following: Ba2+ greater than Sr2+ greater than Ca2+; and (d) the channel discriminates poorly for divalent over monovalent cations (PCa/PNa = 5.9). The sperm Ca2+ channel gamma MS rectifies in symmetrical 10 mM CaCl2, having a maximal slope conductance value of 94 pS at +100 mV applied to the cis side of the bilayer. Under these conditions, a different single-channel activity of lesser conductance became apparent above the gamma MS current at positive membrane potentials. Also in 10 mM Ca2+ solutions, Mg2+ permeates through the main channel when added to the cis side with a PCa/PMg = 2.9, while it blocks when added to the trans side. In 50 mM Ca2+ solutions, the gamma MS open probability has values of 1.0 at voltages more positive than -40 mV and decreases at more negatives potentials, following a Boltzmann function with an E0.5 = -72 mV and an apparent gating charge value of 3.9. These results describe a novel Ca2(+)-selective channel, and suggest that the main channel works as a single multipore assembly.

Substances for the Initiation of Sperm Motility in Egg-Jelly of the Japanese Newt, Cynops pyrrhogaster

1999 ◽  
Vol 16 (5) ◽  
pp. 793-802 ◽  
Author(s):  
Masahiko Ukita ◽  
Tokuko Itoh ◽  
Toshihiko Watanabe ◽  
Akihiko Watanabe ◽  
Kazuo Onitake
Keyword(s):  
Sperm Motility ◽  
Cynops Pyrrhogaster ◽  
Egg Jelly

scholarly journals Characteristics of Sperm Motility Induced on the Egg-Jelly in the Internal Fertilization of the Newt, Cynops pyrrhogaster

2003 ◽  
Vol 20 (3) ◽  
pp. 345-352 ◽  
Author(s):  
Toshihiko Watanabe ◽  
Tokuko Itoh ◽  
Akihiko Watanabe ◽  
Kazuo Onitake
Keyword(s):  
Sperm Motility ◽  
Internal Fertilization ◽  
Cynops Pyrrhogaster ◽  
Egg Jelly

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 ◽  
2012 ◽  
Vol 20 (4) ◽  
pp. 417-422 ◽  
Author(s):  
Eriko Takayama-Watanabe ◽  
Chiara Campanella ◽  
Hideo Kubo ◽  
Akihiko Watanabe
Keyword(s):  
Sperm Motility ◽  
Critical Role ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Homologous Proteins ◽  
Internal Fertilization ◽  
External Fertilization ◽  
Cynops Pyrrhogaster ◽  
Discoglossus Pictus ◽  
Egg Jelly

SummaryThe 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.

The activity for the induction of the sperm acrosome reaction localises in the outer layers and exists in the high-molecular-weight components of the egg-jelly of the newt, Cynops pyrrhogaster

Zygote ◽  
2002 ◽  
Vol 10 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Takayuki Sasaki ◽  
Saori Kamimura ◽  
Hiroyuki Takai ◽  
Akihiko Watanabe ◽  
Kazuo Otinake
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Acrosome Reaction ◽  
Dependent Manner ◽  
Strong Activity ◽  
Maclura Pomifera ◽  
Cynops Pyrrhogaster ◽  
Sds Page ◽  
Egg Jelly ◽  
Dose Dependent

Localisation of the acrosome reaction inducing activity in egg-jelly was examined in the newt, Cynops pyrrhogaster. The jelly has six layers: the J0, J1, J2, J3, J4 and st layers. Jelly was mechanically dissected and placed on a Millipore filter. When sperm were added from the outer surface side of the jelly, most of them exhibited the acrosome reaction after passing through the jelly. When egg-jelly was divided into four layers, strong activity for the induction of acrosome reaction was detected in the outer layers, J4+st. These findings suggest that the acrosome reaction is induced by a substance in the outer layers of the egg-jelly. Among jelly components separated by SDS-PAGE, a fraction of more than 500 kDa in molecular weight induced the acrosome reaction. Wheat germ agglutinin (WGA), Griffonia simplicifoliar agglutinin 1 (GS-1), Maclura pomifera agglutinin (MPA) and Arachis hypogaea agglutinin (PNA) inhibited the induction of the acrosome reaction by jelly extract, and WGA did so in a dose-dependent manner. Those lectins precipitated some molecules of over 500 kDa. These results suggest that the acrosome reaction is induced by the high molecular-weight components of egg-jelly in C. pyrrhogaster.

scholarly journals Distinct Ca2+channels maintain a high motility state of the sperm that may be needed for penetration of egg jelly of the newt,Cynops pyrrhogaster

2013 ◽  
Vol 55 (7) ◽  
pp. 657-667 ◽  
Author(s):  
Tomoe Takahashi ◽  
Megumi Kutsuzawa ◽  
Kogiku Shiba ◽  
Eriko Takayama-Watanabe ◽  
Kazuo Inaba ◽  
...  
Keyword(s):  
Cynops Pyrrhogaster ◽  
Egg Jelly ◽  
Ca2 Channels

Molecular basis of adaptive evolution of sperm motility involved in in vivo fertilization of terrestrial animals

Impact ◽  
2020 ◽  
Vol 2020 (6) ◽  
pp. 73-75
Author(s):  
Akihiko Watanabe
Keyword(s):  
Sexual Reproduction ◽  
Sperm Motility ◽  
Asexual Reproduction ◽  
Acrosome Reaction ◽  
Sperm Morphology ◽  
Adaptive Potential ◽  
Selective Pressures ◽  
The Face ◽  
Genetic Profiles

One of the unifying traits of life on this planet is reproduction, or life's ability to make copies of itself. The mode of reproduction has evolved over time, having almost certainly begun with simple asexual reproduction when the ancestral single celled organism divided into two. Since these beginnings' life has tried out numerous strategies, and perhaps one of the most important and successful has been sexual reproduction. This form of reproduction relies on the union of gametes, otherwise known as sperm and egg. Evolutionarily, sexual reproduction allows for greater adaptive potential because the genes of two unique individuals have a chance to recombine and mix in order to produce a new individual. Unlike asexual reproduction which produces genetically-identical clones of the parent individual, sex produces offspring with novel genes and combinations of genes. Therefore, in the face of new selective pressures there is a higher chance that one of these novel genetic profiles will produce an adaptation that is advantageous in the new circumstances. Dr Akihiko Watanabe is a reproductive biologist based in the Department of Biology, Faculty of Science Yamagata University in Japan, he is currently working on three research projects; a comparative study on the signalling pathways for inducing sperm motility and acrosome reaction in amphibians, the mechanism behind the adaptive modification of sperm morphology and motility, and the origin of sperm motility initiating substance (SMIS).

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