scholarly journals Binding of sperm protein Izumo1 and its egg receptor Juno drives Cd9 accumulation in the intercellular contact area prior to fusion during mammalian fertilization

Development ◽  
2014 ◽  
Vol 141 (19) ◽  
pp. 3732-3739 ◽  
Author(s):  
M. Chalbi ◽  
V. Barraud-Lange ◽  
B. Ravaux ◽  
K. Howan ◽  
N. Rodriguez ◽  
...  
Keyword(s):  
Contact Area ◽  
Intercellular Contact ◽  
Sperm Protein ◽  
Mammalian Fertilization

scholarly journals The sperm protein SPACA4 is required for efficient fertilization in mice

2021 ◽  
Author(s):  
Sarah Herberg ◽  
Yoshitaka Fujihara ◽  
Andreas Blaha ◽  
Karin Panser ◽  
Kiyonari Kobayashi ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Knockout Mice ◽  
Mammalian Species ◽  
Wild Type ◽  
Sperm Protein ◽  
Mammalian Sperm ◽  
Fundamental Process ◽  
Mammalian Fertilization

Fertilization is the fundamental process that initiates the development of a new individual in all sexually reproducing species. Despite its importance, our understanding of the molecular players that govern mammalian sperm-egg interaction is incomplete, partly because many of the essential factors found in non-mammalian species do not have obvious mammalian homologs. We have recently identified the Ly6/uPAR protein Bouncer as a new, essential fertilization factor in zebrafish (Herberg et al., 2018). Here, we show that Bouncer's homolog in mammals, SPACA4, is also required for efficient fertilization in mice. In contrast to fish, where Bouncer is expressed specifically in the egg, SPACA4 is expressed exclusively in the testis. Male knockout mice are severely sub-fertile, and sperm lacking SPACA4 fail to fertilize wild-type eggs in vitro. Interestingly, removal of the zona pellucida rescues the fertilization defect of Spaca4-deficient sperm in vitro, indicating that SPACA4 is not required for the interaction of sperm and the oolemma but rather of sperm and zona pellucida. Our work identifies SPACA4 as an important sperm protein necessary for zona pellucida penetration during mammalian fertilization.

scholarly journals TMEM95 is a sperm membrane protein essential for mammalian fertilization

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ismael Lamas-Toranzo ◽  
Julieta G Hamze ◽  
Enrica Bianchi ◽  
Beatriz Fernández-Fuertes ◽  
Serafín Pérez-Cerezales ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Membrane Fusion ◽  
Zona Pellucida ◽  
Sperm Protein ◽  
Egg Protein ◽  
Egg Membrane ◽  
Sperm Membrane ◽  
Mammalian Fertilization ◽  
Male Specific ◽  
Mechanical Injection

The fusion of gamete membranes during fertilization is an essential process for sexual reproduction. Despite its importance, only three proteins are known to be indispensable for sperm-egg membrane fusion: the sperm proteins IZUMO1 and SPACA6, and the egg protein JUNO. Here we demonstrate that another sperm protein, TMEM95, is necessary for sperm-egg interaction. TMEM95 ablation in mice caused complete male-specific infertility. Sperm lacking this protein were morphologically normal exhibited normal motility, and could penetrate the zona pellucida and bind to the oolemma. However, once bound to the oolemma, TMEM95-deficient sperm were unable to fuse with the egg membrane or penetrate into the ooplasm, and fertilization could only be achieved by mechanical injection of one sperm into the ooplasm, thereby bypassing membrane fusion. These data demonstrate that TMEM95 is essential for mammalian fertilization.

Purification of P26h: a hamster sperm protein

1996 ◽  
Vol 74 (2) ◽  
pp. 227-231 ◽  
Author(s):  
Louise Coutu ◽  
Pascal Des Rosiers ◽  
Robert Sullivan
Keyword(s):  
Aqueous Phase ◽  
Exchange Chromatography ◽  
Dead Volume ◽  
Total Protein Content ◽  
Two Dimensional Gel Electrophoresis ◽  
Sperm Protein ◽  
Step Procedure ◽  
The Matrix ◽  
Mammalian Fertilization ◽  
Triton X

P26h is a 26 kDa glycoprotein, located on the acrosome cap of hamster spermatozoa, involved in the species specificity of gamete interaction. We have purified this protein from hamster spermatozoa collected from the distal cauda region of the epididymis. Its purification was realized following a three-step procedure: detergent extraction, ion-exchange chromatography, and chromatofocusing. Protein partitioning using Triton X-114 (the first step) showed a ratio of 5:1 between the resulting aqueous and detergent phase. P26h was found almost exclusively in the aqueous phase where it represented about 10–12% of the total protein content. When the desalted aqueous phase was loaded on a carboxymethyl column for cation-exchange chromatography, about 80% of the proteins did not bind to the matrix and were eliminated. P26h was eluted from the column with a linear gradient of salt. At this point, P26h had a rate of purification estimated at 45–55%; three other major proteins of <21, 45, and 63 kDa remained in the sample. These undesired proteins were eliminated by submitting these samples to chromatofocusing using a PBE 94 polybuffer exchanger column. Indeed, P26h was collected almost in the dead volume of the column while the other proteins were eluted much later. Two-dimensional gel electrophoresis and Western blotting were performed to determine the purity of P26h. Only one major spot was detected, confirming the purity of P26h. Usefulness of this purified sperm antigen in the understanding of the physiology of mammalian fertilization is discussed.Key words: sperm protein, epididymis, purification.

scholarly journals Shear modulation of intercellular contact area between two deformable cells colliding under flow

2007 ◽  
Vol 40 (13) ◽  
pp. 2891-2897 ◽  
Author(s):  
Sameer Jadhav ◽  
Kit Yan Chan ◽  
Konstantinos Konstantopoulos ◽  
Charles D. Eggleton
Keyword(s):  
Contact Area ◽  
Intercellular Contact ◽  
Shear Modulation

Mammalian fertilization: the strange case of sperm protein 56

BioEssays ◽  
2009 ◽  
Vol 31 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Paul M. Wassarman
Keyword(s):  
Sperm Protein ◽  
Mammalian Fertilization

scholarly journals The conserved fertility factor SPACA4/Bouncer has divergent modes of action in vertebrate fertilization

2021 ◽  
Vol 118 (39) ◽  
pp. e2108777118
Author(s):  
Yoshitaka Fujihara ◽  
Sarah Herberg ◽  
Andreas Blaha ◽  
Karin Panser ◽  
Kiyonori Kobayashi ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Wild Type ◽  
Sperm Protein ◽  
Mammalian Sperm ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Fundamental Process ◽  
Mammalian Fertilization ◽  
Plasminogen Activator Receptor

Fertilization is the fundamental process that initiates the development of a new individual in all sexually reproducing species. Despite its importance, our understanding of the molecular players that govern mammalian sperm–egg interaction is incomplete, partly because many of the essential factors found in nonmammalian species do not have obvious mammalian homologs. We have recently identified the lymphocyte antigen-6 (Ly6)/urokinase-type plasminogen activator receptor (uPAR) protein Bouncer as an essential fertilization factor in zebrafish [S. Herberg, K. R. Gert, A. Schleiffer, A. Pauli, Science 361, 1029–1033 (2018)]. Here, we show that Bouncer’s homolog in mammals, Sperm Acrosome Associated 4 (SPACA4), is also required for efficient fertilization in mice. In contrast to fish, in which Bouncer is expressed specifically in the egg, SPACA4 is expressed exclusively in the sperm. Male knockout mice are severely subfertile, and sperm lacking SPACA4 fail to fertilize wild-type eggs in vitro. Interestingly, removal of the zona pellucida rescues the fertilization defect of Spaca4-deficient sperm in vitro, indicating that SPACA4 is not required for the interaction of sperm and the oolemma but rather of sperm and the zona pellucida. Our work identifies SPACA4 as an important sperm protein necessary for zona pellucida penetration during mammalian fertilization.

Load-Bearing in the Ovine Medial Tibial Condyle: Effect of Meniscectomy

1993 ◽  
Vol 06 (02) ◽  
pp. 100-104 ◽  
Author(s):  
D. M. Pickles ◽  
C. R. Bellenger
Keyword(s):  
Knee Joint ◽  
Contact Area ◽  
Mammalian Species ◽  
Total Removal ◽  
Load Bearing ◽  
Human Knee ◽  
Biochemical Effects ◽  
Pressure Sensitive ◽  
Medial Meniscectomy ◽  
Tibial Condyle

SummaryTotal removal of a knee joint meniscus is followed by osteoarthritis in many mammalian species. Altered load-bearing has been observed in the human knee following meniscectomy but less is known about biochemical effects of meniscectomy in other species. Using pressure sensitive paper in sheep knee (stifle) joints it was found that, for comparable loads, the load-bearing area on the medial tibial condyle was significantly reduced following medial meniscectomy. Also, for loads of between 50 N and 500 N applied to the whole joint, the slope of the regression of contact area against load was much smaller. Following medial meniscectomy, the ability to increase contact area as load increased was markedly reduced.The load bearing area on the medial tibial condyle was reduced following meniscectomy.

An Analytical Thermodynamic Approach to Friction of Rubber on Ice

2012 ◽  
Vol 40 (2) ◽  
pp. 124-150
Author(s):  
Klaus Wiese ◽  
Thiemo M. Kessel ◽  
Reinhard Mundl ◽  
Burkhard Wies
Keyword(s):  
Coefficient Of Friction ◽  
Liquid Layer ◽  
Contact Area ◽  
Leading Edge ◽  
Viscous Friction ◽  
Analytical Approximation ◽  
Real Contact Area ◽  
Length Scales ◽  
Real Contact ◽  
Ice Surface

ABSTRACT The presented investigation is motivated by the need for performance improvement in winter tires, based on the idea of innovative “functional” surfaces. Current tread design features focus on macroscopic length scales. The potential of microscopic surface effects for friction on wintery roads has not been considered extensively yet. We limit our considerations to length scales for which rubber is rough, in contrast to a perfectly smooth ice surface. Therefore we assume that the only source of frictional forces is the viscosity of a sheared intermediate thin liquid layer of melted ice. Rubber hysteresis and adhesion effects are considered to be negligible. The height of the liquid layer is driven by an equilibrium between the heat built up by viscous friction, energy consumption for phase transition between ice and water, and heat flow into the cold underlying ice. In addition, the microscopic “squeeze-out” phenomena of melted water resulting from rubber asperities are also taken into consideration. The size and microscopic real contact area of these asperities are derived from roughness parameters of the free rubber surface using Greenwood-Williamson contact theory and compared with the measured real contact area. The derived one-dimensional differential equation for the height of an averaged liquid layer is solved for stationary sliding by a piecewise analytical approximation. The frictional shear forces are deduced and integrated over the whole macroscopic contact area to result in a global coefficient of friction. The boundary condition at the leading edge of the contact area is prescribed by the height of a “quasi-liquid layer,” which already exists on the “free” ice surface. It turns out that this approach meets the measured coefficient of friction in the laboratory. More precisely, the calculated dependencies of the friction coefficient on ice temperature, sliding speed, and contact pressure are confirmed by measurements of a simple rubber block sample on artificial ice in the laboratory.

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