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.

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

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

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.

Studies on the gastrulation of amphibian embryos: Light and electron microscopic observation of a urodele Cynops pyrrhogaster

Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 669-685
Author(s):  
Norio Nakatsuji
Keyword(s):  
Initial Period ◽  
Electron Microscopic Observation ◽  
Dense Layer ◽  
Electron Microscopic ◽  
Cynops Pyrrhogaster ◽  
Free Region ◽  
Inner Surface ◽  
20 Nm ◽  
Yolk Platelet ◽  
Scanning Electron

The course of gastrulation in embryos of a urodele, Cynops pyrrhogaster, was studied with 1 µm Epon sections and transmission and scanning electron microscopy. During the initial period of gastrulation, the bottle cells and a groove are formed in the dorsal part. The outer ends of the bottle cells have many microvilli, an electron-dense layer and many small vesicles. Microtubules are present parallel to the long axis of the bottle cells, and a yolk-platelet-free region is observed at the inner end. Thereafter, the archenteric roof makes contact with the inner surface of the blastocoelic wall. Cells of the archenteric roof form lobopodia, filopodia and lamellipodia. These cells make many focal contacts, having gaps of less than 20 nm, with the blastocoelic wall. Invaginating mesodermal cells of the lateral and ventral parts also form pseudopodia, and are in contact with the blastocoelic wall. Some of these cells appear to flatten against the wall. These observations suggest that, after the bottle cells and the blastoporal groove are formed, the invaginating cells actively migrate along the inner surface of the blastocoelic wall, and that these locomotive forces have an important role inthe morphogenetic movements during gastrulation.

Egg-jelly structure promotes efficiency of internal fertilization in the newt,Cynops pyrrhogaster

2002 ◽  
Vol 292 (3) ◽  
pp. 314-322 ◽  
Author(s):  
Tokuko Itoh ◽  
Saori Kamimura ◽  
Akihiko Watanabe ◽  
Kazuo Onitake
Keyword(s):  
Internal Fertilization ◽  
Cynops Pyrrhogaster ◽  
Egg Jelly

Significance of egg-jelly substances in the internal fertilization of the newt, Cynops pyrrhogaster

2000 ◽  
Vol 126 (2) ◽  
pp. 121-128 ◽  
Author(s):  
Kazuo Onitake ◽  
Hiroyuki Takai ◽  
Masahiko Ukita ◽  
Jun-Ichi Mizuno ◽  
Takayuki Sasaki ◽  
...  
Keyword(s):  
Internal Fertilization ◽  
Cynops Pyrrhogaster ◽  
Egg Jelly

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

Observation of Concanavalin-A receptors on hydrated planar erythrocyte membrane film by in situ electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 608-609
Author(s):  
Neng-Bo He ◽  
S.W. Hui
Keyword(s):  
Lipid Bilayers ◽  
Erythrocyte Membrane ◽  
Lipid Membranes ◽  
Surface Film ◽  
Biological Membranes ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Black Lipid Membranes ◽  
Fine Mesh ◽  
Planar Films

Monolayers and planar "black" lipid membranes have been widely used as models for studying the structure and properties of biological membranes. Because of the lack of a suitable method to prepare these membranes for electron microscopic observation, their ultrastructure is so far not well understood. A method of forming molecular bilayers over the holes of fine mesh grids was developed by Hui et al. to study hydrated and unsupported lipid bilayers by electron diffraction, and to image phase separated domains by diffraction contrast. We now adapted the method of Pattus et al. of spreading biological membranes vesicles on the air-water interfaces to reconstitute biological membranes into unsupported planar films for electron microscopic study. hemoglobin-free human erythrocyte membrane stroma was prepared by hemolysis. The membranes were spreaded at 20°C on balanced salt solution in a Langmuir trough until a surface pressure of 20 dyne/cm was reached. The surface film was repeatedly washed by passing to adjacent troughs over shallow partitions (fig. 1).

The Scanning Electron Microscopic Observation of the Vestibular Sensory Epithelia

1969 ◽  
Vol 27 ◽  
pp. 40-41
Author(s):  
D.J. Lim ◽  
W.C. Lane
Keyword(s):  
Semicircular Canals ◽  
Electron Microscopic Observation ◽  
Gravitational Acceleration ◽  
Electron Microscopic ◽  
Sensory Epithelia ◽  
Scanning Electron Microscopic ◽  
Vestibular Sensory Epithelia ◽  
And Function ◽  
Sand Piles ◽  
Active Investigation

The morphology and function of the vestibular sensory organs has been extensively studied during the last decade with the advent of electron microscopy and electrophysiology. The opening of the space age also accelerated active investigation in this area, since this organ is responsible for the sensation of balance and of linear, angular and gravitational acceleration.The vestibular sense organs are formed by the saccule, utricle and three ampullae of the semicircular canals. The maculae (sacculi and utriculi) have otolithic membranes on the top of the sensory epithelia. The otolithic membrane is formed by a layer of thick gelatin and sand-piles of calcium carbonate crystals (Fig.l).

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