scholarly journals Cytochemical detection of hyaluronidase activity in single human and mouse sperm by an improved substrate-film technique.

1984 ◽  
Vol 32 (1) ◽  
pp. 63-66 ◽  
Author(s):  
R Waibel ◽  
L C Ginsberg ◽  
G Ficsor
Keyword(s):  
Germ Cells ◽  
Screening Method ◽  
Human Sperm ◽  
Simple Method ◽  
Male Germ Cells ◽  
Mouse Sperm ◽  
Hyaluronidase Activity ◽  
Film Method ◽  
Human And Mouse ◽  
Substrate Film

A substrate-film method is described that allows the detection of hyaluronidase activity in nearly 100% of single human and mouse sperm. The level of hyaluronidase activity as determined by halo diameters was greater in mouse than in human sperm. This simple method may have use as a screening method for identifying compounds that cause developmental or genetic defects in male germ cells, or for the diagnosis of infertility due to decreased hyaluronidase activity.

scholarly journals Acidic hyaluronidase activity is present in mouse sperm and is reduced in the absence of SPAM1: Evidence for a role for hyaluronidase 3 in mouse and human sperm

2010 ◽  
Vol 77 (9) ◽  
pp. 759-772 ◽  
Author(s):  
Kristen L. Reese ◽  
Rolands G. Aravindan ◽  
Genevieve S. Griffiths ◽  
Minghai Shao ◽  
Yipei Wang ◽  
...  
Keyword(s):  
Human Sperm ◽  
Mouse Sperm ◽  
Hyaluronidase Activity

scholarly journals Conserved Mechanism of Bicarbonate-Induced Sensitization of CatSper Channels in Human and Mouse Sperm

2021 ◽  
Vol 9 ◽  
Author(s):  
Juan J. Ferreira ◽  
Pascale Lybaert ◽  
Lis C. Puga-Molina ◽  
Celia M. Santi
Keyword(s):  
Human Sperm ◽  
Membrane Depolarization ◽  
Concentration Increase ◽  
Epididymal Sperm ◽  
Soluble Adenylyl Cyclase ◽  
Mouse Sperm ◽  
Intracellular Ca ◽  
Sperm Membrane ◽  
Human And Mouse ◽  
Kinase A

To fertilize an egg, mammalian sperm must undergo capacitation in the female genital tract. A key contributor to capacitation is the calcium (Ca2+) channel CatSper, which is activated by membrane depolarization and intracellular alkalinization. In mouse epididymal sperm, membrane depolarization by exposure to high KCl triggers Ca2+ entry through CatSper only in alkaline conditions (pH 8.6) or after in vitro incubation with bicarbonate (HCO3–) and bovine serum albumin (capacitating conditions). However, in ejaculated human sperm, membrane depolarization triggers Ca2+ entry through CatSper in non-capacitating conditions and at lower pH (< pH 7.4) than is required in mouse sperm. Here, we aimed to determine the mechanism(s) by which CatSper is activated in mouse and human sperm. We exposed ejaculated mouse and human sperm to high KCl to depolarize the membrane and found that intracellular Ca2+ concentration increased at pH 7.4 in sperm from both species. Conversely, intracellular Ca2+ concentration did not increase under these conditions in mouse epididymal or human epididymal sperm. Furthermore, pre-incubation with HCO3– triggered an intracellular Ca2+ concentration increase in response to KCl in human epididymal sperm. Treatment with protein kinase A (PKA) inhibitors during exposure to HCO3– inhibited Ca2+ concentration increases in mouse epididymal sperm and in both mouse and human ejaculated sperm. Finally, we show that soluble adenylyl cyclase and increased intracellular pH are required for the intracellular Ca2+ concentration increase in both human and mouse sperm. In summary, our results suggest that a conserved mechanism of activation of CatSper channels is present in both human and mouse sperm. In this mechanism, HCO3– in semen activates the soluble adenylyl cyclase/protein kinase A pathway, which leads to increased intracellular pH and sensitizes CatSper channels to respond to membrane depolarization to allow Ca2+ influx. This indirect mechanism of CatSper sensitization might be an early event capacitation that occurs as soon as the sperm contact the semen.

scholarly journals Cleavage of arginyl-arginine and lysyl-arginine from the C-terminus ofpro-hormone peptides by human germinal angiotensin I-converting enzyme (ACE) and the C-domain of human somatic ACE

1997 ◽  
Vol 328 (2) ◽  
pp. 587-591 ◽  
Author(s):  
R. Elwyn ISAAC ◽  
A. Tracy WILLIAMS ◽  
Mohammed SAJID ◽  
Pierre CORVOL ◽  
David COATES
Keyword(s):  
Germ Cells ◽  
Human Sperm ◽  
Peptide Hormone ◽  
Maximal Activity ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Male Germ Cells ◽  
High Affinity ◽  
Angiotensin I Converting Enzyme ◽  
C Terminus

Mammalian germinal angiotensin I-converting enzyme (gACE) is a single-domain dipeptidyl carboxypeptidase found exclusively in male germ cells, which has almost identical sequence and enzymic properties with the C-domain of the two-domain somatic ACE. Mutant mice that do not express gACE are infertile, suggesting a role for the enzyme in the processing of undefined peptides involved in fertilization. A number of spermatid peptides [e.g. cholecystokinin (CCK) and gastrin] are processed from pro-hormones by endo- and exo-proteolytic cleavages which might generate substrates for gACE. We have shown that peptide hormone intermediates with Lys/Arg-Arg at the C-terminus are high-affinity substrates for human gACE. gACE from human sperm cleaved Arg-Arg from the C-terminus of the CCK5-GRR (GWMDFGRR), a peptide corresponding to the C-terminus of a CCK-gastrin prohormone intermediate. Hydrolysis of CCK5-GRR by recombinant human C-domain ACE was Cl- dependent, with maximal activity achieved in 5-10 mM NaCl at pH 6.4. C-Domain ACE cleaved Lys/Arg-Arg from the C-terminus of dynorphin-(1-7), a pro-TRH peptide KRQHPGKR, and two insect peptides FSPRLGKR and FSPRLGRR. C-Domain ACE displayed high affinity towards all these substrates with Vmax/Km values between 14 and 113 times greater than the Vmax/Km for the conversion of the best known ACE substrate, angiotensin I, into angiotensin II. In conclusion, we have identified a new class of substrates for human gACE, and we suggest that gACE might be an alternative to carboxypeptidase E for the trimming of basic dipeptides from the C-terminus of intermediates generated from pro-hormones by subtilisin-like convertases in human male germ cells.

scholarly journals NANOS2 suppresses the cell cycle by repressing mTORC1 activators in embryonic male germ cells

iScience ◽  
2021 ◽  
pp. 102890
Author(s):  
Ryuki Shimada ◽  
Hiroko Koike ◽  
Takamasa Hirano ◽  
Yuzuru Kato ◽  
Yumiko Saga
Keyword(s):  
Cell Cycle ◽  
Germ Cells ◽  
Male Germ Cells

scholarly journals ELECTRON MICROSCOPE STUDIES ON THE DICTYOSOMES AND ACROBLASTS IN THE MALE GERM CELLS OF THE CRICKET

1956 ◽  
Vol 2 (4) ◽  
pp. 123-128 ◽  
Author(s):  
H. W. Beams ◽  
T. N. Tahmisian ◽  
R. L. Devine ◽  
Everett Anderson
Keyword(s):  
Electron Microscope ◽  
Golgi Apparatus ◽  
Electron Micrographs ◽  
Germ Cells ◽  
Light Microscope ◽  
Golgi Body ◽  
Duplex Structure ◽  
Male Germ Cells ◽  
Secondary Spermatocyte ◽  
A Chain

The dictyosome (Golgi body) in the secondary spermatocyte of the cricket appears in electron micrographs as a duplex structure composed of (a) a group of parallel double-membraned lamellae and (b) a group of associated vacuoles arranged along the compact lamellae in a chain-like fashion. This arrangement of ultramicroscopic structure for the dictyosomes is strikingly comparable to that described for the Golgi apparatus of vertebrates. Accordingly, the two are considered homologous structures. Associated with the duplex structure of the dictyosomes is a differentiated region composed of small vacuoles. This is thought to represent the pro-acrosome region described in light microscope preparations. In the spermatid the dictyosomes fuse, giving rise to the acroblast. Like the dictyosomes, the acroblasts are made up of double-membraned lamellae and associated vacuoles. In addition, a differentiated acrosome region is present which, in some preparations, may display the acrosome vacuole and granule. Both the dictyosomes and acroblasts are distinct from mitochondria.

scholarly journals Male germ cells and photoreceptors, both dependent on close cell–cell interactions, degenerate upon ClC-2 Cl− channel disruption

2001 ◽  
Vol 20 (6) ◽  
pp. 1289-1299 ◽  
Author(s):  
Michael R. Bösl ◽  
Valentin Stein ◽  
Christian Hübner ◽  
Anselm A. Zdebik ◽  
Sven-Eric Jordt ◽  
...  
Keyword(s):  
Germ Cells ◽  
Cell Interactions ◽  
Male Germ Cells ◽  
Cl Channel ◽  
Cell Cell
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