scholarly journals Acrosome reaction of fowl sperm: Evidence for shedding of the acrosomal cap in intact form to release acrosomal enzyme

2013 ◽  
Vol 92 (3) ◽  
pp. 798-803 ◽  
Author(s):  
M.U. Ahammad ◽  
C. Nishino ◽  
H. Tatemoto ◽  
N. Okura ◽  
S. Okamoto ◽  
...  
Keyword(s):  
Acrosome Reaction ◽  
Acrosomal Enzyme

Evidence that acrosin activity is important for the development of fusibility of mammalian spermatozoa with the oolemma: inhibitor studies using the golden hamster

Zygote ◽  
1993 ◽  
Vol 1 (1) ◽  
pp. 79-91 ◽  
Author(s):  
Hiroko Takano ◽  
R. Yanagimachi ◽  
Umbert A. Urch
Keyword(s):  
Plasma Membrane ◽  
Acrosome Reaction ◽  
Free Medium ◽  
Inhibitory Effects ◽  
Chloromethyl Ketone ◽  
Gamete Fusion ◽  
Sperm Plasma Membrane ◽  
Acrosomal Enzyme ◽  
Acrosin Activity ◽  
Mammalian Spermatozoa

SummaryThe sperm plasma membrane over the equatorial segment of the acrosome gains the ability to fuse with the oolemma some time during, or after, the acrosome reaction. Since acrosin is a major component of the acrosome matrix that dissolves during the acrosome reaction, we sought to determine the effect of acrosin inhibitors on the sperm's ability to fuse with the oolemma. Five acrosin inhibitors (soybean trypsin inhibitor (SBTI), leupeptin, benzamidine, N-p-tosyl-1-lysin-chloromethyl ketone (TLCK) and phenylmethylsulphonyl fluoride (PMSF) and one non-acrosin inhibitor (N-p-tosyl-1-phenylalanine chloromethyl ketone (TPCK) were tested at non-toxic levels (below motility-disturbing concentrations). These inhibitors were added at three different times: (1) during the acrosome reaction of spermatozoa, (2) during sperm-oocyte contact and fusion, and (3) soon after sperm-oocyte fusion was completed. TLCK prevented sperm-oocyte fusion by inhibiting the acrosome reaction.PMSF inhibited gamete fusion, without inhibiting the acrosome reaction. SBTI, leupeptin and benzamidine also inhibited gamete fusion, but they had no effect if spermatozoa were allowed to acrosome-react in inhibitor-free medium. TPCK was without any inhibitory effects, suggesting that chymotrypsin-like enzymes are not involved in gamete fusion. Although acrosin inhibitors prevented acrosome-reacted spermatozoa from becoming fusion-competent, acrosin (and trypsin) alone could not make the plasma membrane of acrosome-intact spermatozoa fusion-competent. The data suggest that (1) the plasma membrane of the acrosomal region first undergoes dramatic changes immediately before or during the acrosome reaction and (2) acrosin released from the acrosome during the acrosome reaction further alters biophysical and biochemical characteristics of the plasma membrane over the equatorial segment. Such dual changes make the plasma membrane of this specialised region of the spermatozoon competent to fuse with the oolemma. Acrosin may not be the only acrosomal enzyme to participate in these changes.

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).

TRPM8 in mouse sperm detects temperature changes and may influence the acrosome reaction

2011 ◽  
Vol 226 (6) ◽  
pp. 1620-1631 ◽  
Author(s):  
Pablo Martínez-López ◽  
Claudia L. Treviño ◽  
José Luis de la Vega-Beltrán ◽  
Gerardo De Blas ◽  
Esteban Monroy ◽  
...  
Keyword(s):  
Acrosome Reaction ◽  
Temperature Changes ◽  
Mouse Sperm

scholarly journals Formyl-met-leu-phe induces chemotaxis and acrosomal enzyme release in bull sperm

FEBS Letters ◽  
1980 ◽  
Vol 115 (2) ◽  
pp. 178-180 ◽  
Author(s):  
S. Vijayasarathy ◽  
S. Shivaji ◽  
M. Iqbal ◽  
P. Balaram
Keyword(s):  
Enzyme Release ◽  
Bull Sperm ◽  
Acrosomal Enzyme

scholarly journals Epidermal growth factor alleviates the negative impact of urea on frozen-thawed bovine sperm, but the subsequent developmental competence is compromised

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rasoul Kowsar ◽  
Shahrzad Ronasi ◽  
Nima Sadeghi ◽  
Khaled Sadeghi ◽  
Akio Miyamoto
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Dna Fragmentation ◽  
Acrosome Reaction ◽  
Developmental Competence ◽  
Ros Production ◽  
Sperm Capacitation ◽  
Bovine Sperm ◽  
Epidermal Growth ◽  
High Level

AbstractUpon insemination, sperm cells are exposed to components of the female reproductive tract (FRT) fluids, such as urea and epidermal growth factor (EGF). It has been shown that both urea and EGF use EGF receptor signaling and produce reactive oxygen species (ROS) that are required at certain levels for sperm capacitation and acrosome reaction. We therefore hypothesized that during bovine sperm capacitation, a high level of urea and EGF could interfere with sperm function through overproduction of ROS. High-level urea (40 mg/dl urea is equal to 18.8 mg/dl of blood urea nitrogen) significantly increased ROS production and TUNEL-positive sperm (sperm DNA fragmentation, sDF) percentage, but decreased HOS test score, progressive motility, acrosome reaction and capacitation. The EGF reversed the negative effects of urea on all sperm parameters, with the exception of ROS production and DNA fragmentation, which were higher in urea-EGF-incubated sperm than in control-sperm. The developmental competence of oocytes inseminated with urea-EGF-incubated sperm was significantly reduced compared to the control. A close association of ROS production or sDF with 0-pronuclear and sperm non-capacitation rates was found in the network analysis. In conclusion, EGF enhanced urea-reduced sperm motility; however, it failed to reduce urea-increased sperm ROS or sDF levels and to enhance subsequent oocyte competence. The data suggests that any study to improve sperm quality should be followed by a follow-up assessment of the fertilization outcome.

scholarly journals STUDIES ON THE ACROSOME. II. ACROSOME REACTION IN STARFISH SPERMATOZOA

1954 ◽  
Vol 107 (2) ◽  
pp. 203-218 ◽  
Author(s):  
JEAN C. DAN ◽  
A. KITAHARA ◽  
T. KOHRI
Keyword(s):  
Acrosome Reaction

Specific binding of acrosome-reaction-inducing substance to the head of starfish spermatozoa

Zygote ◽  
1993 ◽  
Vol 1 (2) ◽  
pp. 121-127 ◽  
Author(s):  
Akira Ushiyama ◽  
Takeo Araki ◽  
Kazuyoshi Chiba ◽  
Motonori Hoshi
Keyword(s):  
Acrosome Reaction ◽  
Specific Binding ◽  
Molecular Size ◽  
Polystyrene Latex ◽  
Anterior Region ◽  
Head Region ◽  
Signal Molecule ◽  
Jelly Coat ◽  
Plot Analysis ◽  
Species Specific

In the starfish, spermatozoa undergo the acrosome reaction upon encountering the jelly coat of eggs. A highly sulphated glycoprotein in the jelly coat is called acrosome-reaction-inducing substance (ARIS) because it is the key signal molecule to trigger the acrosome reaction. The activity of ARIS is mainly attributed to its sulphate and saccharide residues. The extremely large molecular size and speciesspecific action of ARIS suggest the presence of a specific ARIS receptor on the sperm surface, but no experimental evidence for the receptor has been presented. We therefore measured specific binding of ARIS and its pronase digest (P-ARIS), which retains the full activity of ARIS, to homologous spermatozoa by using fluorescien-isothiocyanate-labelled ARIS and125 I-labelled P-ARIS, respectively. The spermatozoa had the ability to bind ARIS, as well as P-ARIS, specifically. The binding was species-specific, and mostly localised to the head region of spermatozoa. Scatchard plot analysis indicated the presence of one class of ARIS receptor on the surface of acrosome-intact speramatozoa. Furthermore, the specific binding of P-ARIS to the anterior region of sperm heads was microscopically confirmed by using P-ARIS conjugated to polystyrene latex beads with intense fluorescence. It is concluded that starfish spermatozoa have a specific receptor for ARIS on the surface of the anterior region of heads.

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