Sperm from beta 1,4-galactosyltransferase-null mice are refractory to ZP3-induced acrosome reactions and penetrate the zona pellucida poorly

Development ◽  
1997 ◽  
Vol 124 (20) ◽  
pp. 4121-4131 ◽  
Author(s):  
Q. Lu ◽  
B.D. Shur
Keyword(s):  
Acrosome Reaction ◽  
Direct Evidence ◽  
Calcium Ionophore ◽  
Wild Type ◽  
Sperm Surface ◽  
Gamete Recognition ◽  
Dependent Signal ◽  
Relative Inability ◽  
Egg Coat

A variety of sperm surface components have been suggested to mediate gamete recognition by binding to glycoside ligands on the egg coat glycoprotein ZP3. The function of each of these candidate receptors is based upon varying degrees of circumstantial and direct evidence; however, the effects on fertilization of targeted mutations in any of these candidate receptors have not yet been reported. In this paper, we describe the effects of targeted mutations in beta1,4-galactosyltransferase, the best studied of the candidate receptors for ZP3. Surprisingly, galactosyltransferase-null (gt[−/−]) males are fertile; however, sperm from gt(−/−) males bind less radiolabeled ZP3 than wild-type sperm, and are unable to undergo the acrosome reaction in response to either ZP3 or anti-galactosyltransferase antibodies, as do wild-type sperm. In contrast, gt(−/−) sperm undergo the acrosome reaction normally in response to calcium ionophore, which bypasses the requirement for ZP3 binding. The inability of gt(−/−) sperm to undergo a ZP3-induced acrosome reaction renders them physiologically inferior to wild-type sperm, as assayed by their relative inability to penetrate the egg coat and fertilize the oocyte in vitro. Thus, although ZP3 binding and subsequent induction of the acrosome reaction are dispensable for fertilization, they impart a physiological advantage to the fertilizing sperm. A second strain of mice was created that is characterized by a loss of of the long galactosyltransferase isoform responsible for ZP3-dependent signal transduction, but which maintains normal levels of Golgi galactosylation. Sperm from these mice show that the defective sperm-egg interactions in gt(−/−) mice are due directly to a loss of the long galactosyltransferase isoform from the sperm surface and are independent of the state of intracellular galactosylation during spermatogenesis.

scholarly journals Sperm binding to ZP2-coated beads improve the efficiency of porcine in vitro fertilisation

Reproduction ◽  
2020 ◽  
Vol 160 (5) ◽  
pp. 725-735
Author(s):  
Julieta Gabriela Hamze ◽  
María Jiménez-Movilla ◽  
Raquel Romar
Keyword(s):  
Acrosome Reaction ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
In Vitro Fertilisation ◽  
Sperm Binding ◽  
Fertilisation Rate ◽  
Gamete Recognition ◽  
Boar Spermatozoa

The role of specific zona pellucida (ZP) glycoproteins in gamete interaction has not yet been elucidated in many species. A recently developed 3D model based on magnetic sepharose beads (B) conjugated to recombinant ZP glycoproteins (BZP) and cumulus cells (CBZP) allows the study of isolated ZP proteins in gamete recognition studies. The objective of this work was to study the role of porcine ZP2, ZP3 and ZP4 proteins in sperm binding, cumulus cell adhesion and acrosome reaction triggering. ZP protein-bound beads were incubated with fresh ejaculated boar spermatozoa and isolated cumulus cells for 24 h. The number of sperm bound to the beads, the acrosomal shrouds (presence of acrosomal content) on the bead’s surface, and the acrosome integrity (by means of PNA-FITC lectin) in bound and unbound sperm were studied. Finally, in vitro matured porcine oocytes mixed with BZP2 were inseminated in vitro using fresh sperm and fertilisation results evaluated. Over 60% of beads had at least one sperm bound after 2 h of coincubation. ZP2-beads (BZP2) and cumulus-ZP2-bead complexes (CBZP2) reached the highest number of sperm per bead, whereas BZP3 and BZP4 models showed the highest number of unbound reacted sperm cells and acrosomal shrouds. Fertilisation efficiency and monospermy rate increased when oocytes were fertilised in the presence of BZP2. We, therefore, conclude that in pigs, it is mainly ZP2 that is involved in sperm-ZP binding whereas ZP3 and ZP4 induce acrosome reaction. Using magnetic sepharose ZP2-bound beads might be a valuable tool to improve the fertilisation rate in pigs.

In vitro induction of the acrosome reaction in ovine spermatozoa by calcium ionophore A23187

2003 ◽  
Vol 51 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Ö. Uçar ◽  
T. J. Parkinson
Keyword(s):  
Phase Contrast ◽  
Acrosome Reaction ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Contrast Microscopy ◽  
The Relationship ◽  
In Vitro Induction ◽  
Artificial Vagina

The relationship between concentration of calcium ionophore A23187 and incubation time upon the proportion of spermatozoa undergoing acrosome reaction (AR) in vitro was investigated in rams from a commercial artificial insemination (AI) program. Two ejaculates were collected by artificial vagina from each of nine rams of three breeds (Finn Dorset, Charolais and Suffolk) aged 8-36months. Each ejaculate was diluted in a skimmed milk extender. Spermatozoa were thereafter incubated for 45 or 60min in modified Tyrode's medium (TALP) which contained either zero, 0.1 or 1.0µM/l A23187. After fixing in 10% formaldehyde, the number of spermatozoa that had undergone AR was determined by phase contrast microscopy. In pre-incubation samples, 21.3± 3.3% of spermatozoa had undergone AR. Percentages of acrosome reacted spermatozoa were significantly (P<0.001) increased after incubation with A23187. After incubation with 0.1µM/l A23187 for 45 and 60min there were 22.4±3.0% and 31.7±4.3% acrosome reacted spermatozoa, respectively. After incubation with 1.0µM/l A23187 for 45 and 60min there were 46.2±6.5% and 53.8±5.9% acrosome reacted spermatozoa, whilst corresponding numbers in control samples were 17.0±2.7% and 22.3±4.2%. There was also a significant (P<0.001) effect of individual animals upon the responses to different concentrations of A23187. These findings indicate that (i) A23187 can be used to assess the AR of ovine spermatozoa in vitro and (ii) there are effects of individual animals upon the proportion of spermatozoa undergoing AR.

Monocyte-Derived Microparticles Improve Hemostasis in Factor VIIIDeficient Mice: Exploring the Role of PSGL-1/P-Selectin.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3386-3386
Author(s):  
Peter L. Gross ◽  
Nima Vaezzadeh ◽  
Lori Ivicic ◽  
Ran Ni ◽  
Bruno Esposito ◽  
...  
Keyword(s):  
Blood Loss ◽  
High Speed ◽  
Calcium Ionophore ◽  
Ionophore A23187 ◽  
Wild Type ◽  
Spontaneous Bleeding ◽  
Platelet Accumulation ◽  
Deficient Mice ◽  
Tail Clip

Abstract Introduction: Microparticles derived from leukocytes contribute to fibrin formation at thrombi in vivo and factor VIII-deficient (FVIII) mice treated with an agent that elevates their microparticles have decreased bleeding. A novel therapy for hemophilia patients with inhibitors is needed. We evaluated whether microparticles generated in vitro could improve hemostasis in FVIII mice. Methods: Mouse CD11b positive monocytes, isolated by MACS, or cultured monocytic cells (WEHI274.1) were treated with the calcium ionophore A23187. The resulting microparticles (isolated by differential centrifugation, and defined as CD18 positive events less than 1 μm diameter) or PIPES buffer were infused intravenously into FVIII-deficient mice (B6.129S4-F8tm1Kaz) or control wild type B6.129 mice prior to evaluation. The amount of platelets in laser-generated thrombi in cremaster muscle arterioles was evaluated using high-speed intravital fluorescence microscopy. The amount of hemoglobin shed from a 2 mm tail tip amputation measured blood loss. Results: Infusion of MPs at doses above 1000/g resulted in the death of wild type mice; FVIII-deficient mice tolerated MPs at doses up to 4000/g. Blood loss after tail clip in FVIII-deficient mice was 6-fold higher than blood loss from wild type mice. Blood loss after tail clip in FVIII-deficient mice was reduced to normal after the infusion of MPs at concentrations as low as 400/g. MPs, at 400/g, from CD11b positive cells isolated from wild type, FVIII-deficient mice or PSGL-1-deficient mice all similarly reduced blood loss after tail clip in FVIII-deficient mice. The biological half life of MP effect on tail-bleeding was 3 hours. Platelet accumulation in cremaster arteriolar thrombi was impaired in FVIII-deficient mice. Infusion of MPs at a concentration of 1000/g normalized platelet accumulation, but infusion of MPs at a lower concentration (400/g) did not. Conclusion: Abnormal hemostasis in FVIII-deficient mice can be temporarily reversed by the infusion of in vitro generated monocyte-derived MPs, including MPs derived from monocytes from FVIII-deficient or PSGL-1-deficient mice. The dose whereby MPs normalize FVIII-deficient mice is different between the hemostasis and thrombosis models. To explore whether P-selectin at injuries is required for the effect of MPs, we have generated by cross-breeding FVIII/P-selectin double deficient mice. These mice are born at expected mendelian frequency. Two of 20 male FVIII/P-selectin double deficient mice had spontaneous bleeding at 8 weeks of age, one in the thigh and one from the ear. FVIII/P-selectin double deficient mice also have prolonged tail bleeding times, which will serve as a model for testing the P-selectin targeting of microparticles.

scholarly journals Progress of sperm IZUMO1 relocation during spontaneous acrosome reaction

Reproduction ◽  
2014 ◽  
Vol 147 (2) ◽  
pp. 231-240 ◽  
Author(s):  
Natasa Sebkova ◽  
Lukas Ded ◽  
Katerina Vesela ◽  
Katerina Dvorakova-Hortova
Keyword(s):  
Fusion Protein ◽  
Acrosome Reaction ◽  
Mating Behaviour ◽  
Calcium Ionophore ◽  
Cumulus Cells ◽  
Sperm Head ◽  
High Rate ◽  
Field Mice ◽  
Species Specific

It has been recently shown in mice that sperm undergo acrosome reaction (AR) by passing through cumulus cells; furthermore, the acrosome-reacted sperm can bind to zona pellucida and consequently fertilise the egg. During AR, the relocation of the primary fusion protein IZUMO1 into the equatorial segment is crucial for sperm–egg fusion. There is a high rate of spontaneous AR in rodents, with up to 60% in promiscuous species. The aim of this study was to clarify whether the IZUMO1 relocation in sperm after spontaneous and induced AR is the same, and whether there is a correlation between the speed of IZUMO1 relocation and species-specific mating behaviour in field mice. Immunofluorescent detection of IZUMO1 dynamics during the in vitro capacitation, spontaneous, calcium ionophore and progesterone-induced AR was monitored. Our results show that during spontaneous AR, there is a clear IZUMO1 relocation from the acrosomal cap to the equatorial segment, and further over the whole sperm head. In addition, there is positive tail tyrosine phosphorylation (TyrP) associated with hyperactive motility. Moreover, the beginning and the progress of IZUMO1 relocation and tail TyrP positively correlate with the level of promiscuity and the acrosome instability in promiscuous species. The findings that crucial molecular changes essential for sperm–egg fusion represented by dynamic movements of IZUMO1 also happen during spontaneous AR are vital for understanding fertilisation in mice.

scholarly journals Complement Receptor 1 Expression on Mouse Erythrocytes Mediates Clearance of Streptococcus pneumoniae by Immune Adherence

2010 ◽  
Vol 78 (7) ◽  
pp. 3129-3135 ◽  
Author(s):  
Jie Li ◽  
Jennifer P. Wang ◽  
Ionita Ghiran ◽  
Anna Cerny ◽  
Alexander J. Szalai ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Direct Evidence ◽  
Wild Type Mouse ◽  
Complement Receptor ◽  
Blood Clearance ◽  
Wild Type ◽  
Immune Adherence ◽  
Complement Receptor 1

ABSTRACT Complement-containing immune complexes can be presented to phagocytes by human erythrocytes bearing complement receptor 1 (CR1). Although this has long been assumed to be a mechanism by which humans are able to protect themselves from “extracellular” bacteria such as pneumococci, there is little direct evidence. In these studies we have investigated this question by comparing results for erythrocytes from transgenic mice expressing human CR1 on their erythrocytes to the results for wild-type mouse erythrocytes that do not express CR1. We demonstrate that human CR1 expression on murine erythrocytes allows immune adherence to beads opsonized with either mouse or human serum as a source of complement. The role of CR1 in immune adherence was supported by studies showing that it was blocked by the addition of antibody to human CR1. Furthermore, human CR1 expression enhances the immune adherence of opsonized pneumococci to erythrocytes in vitro, and the pneumococci attached to erythrocytes via CR1 can be transferred in vitro to live macrophages. Even more importantly, we observed that if complement-opsonized pneumococci are injected intravenously with CR1+ mouse erythrocytes into wild-type mice (after a short in vitro incubation), they are cleared faster than opsonized pneumococci similarly injected with wild-type mouse erythrocytes. Finally, we have shown that the intravenous (i.v.) injection of pneumococci into CR1+ mice also results in more rapid blood clearance than in wild-type mice. These data support that immune adherence via CR1 on erythrocytes likely plays an important role in the clearance of opsonized bacteria from human blood.

scholarly journals ATP amplifies NADPH-dependent and -independent neutrophil extracellular trap formation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aderonke Sofoluwe ◽  
Marc Bacchetta ◽  
Mehdi Badaoui ◽  
Brenda R. Kwak ◽  
Marc Chanson
Keyword(s):  
Calcium Ionophore ◽  
Neutrophil Extracellular Traps ◽  
Calcium Ionophore A23187 ◽  
Neutrophil Extracellular Trap ◽  
Ionophore A23187 ◽  
Wild Type ◽  
Extracellular Traps ◽  
Brilliant Blue Fcf ◽  
Pathological Conditions

Abstract Neutrophils are the first immune cells to kill invading microbes at sites of infection using a variety of processes, including the release of proteases, phagocytosis and the production of neutrophil extracellular traps (NETs). NET formation, or NETosis, is a specific and highly efficient process, which is induced by a variety of stimuli leading to expulsion of DNA, proteases and antimicrobial peptides to the extracellular space. However, uncontrolled NETosis may lead to adverse effects and exert tissue damage in pathological conditions. Here, we show that the ATP channel pannexin1 (Panx1) is functionally expressed by bone marrow-derived neutrophils (BMDNs) of wild-type (WT) mice and that ATP contributes to NETosis induced in vitro by the calcium ionophore A23187 or phorbol 12-myristate 13-acetate (PMA). Interestingly, neutrophils isolated from Panx1−/− mice showed reduced and/or delayed induction of NETosis. Brilliant blue FCF dye (BB-FCF), a Panx1 channel inhibitor, decreased NETosis in wild-type neutrophils to the extent observed in Panx1−/− neutrophils. Thus, we demonstrate that ATP and Panx1 channels contribute to NETosis and may represent a therapeutic target.

45 ACROSOME REACTION AND HETEROLOGOUS ZONA BINDING ASSAY OF FROZEN STALLION SPERM AFTER HYPERACTIVATION

2016 ◽  
Vol 28 (2) ◽  
pp. 152
Author(s):  
M. A. Lagares ◽  
H. S. Martins ◽  
M. R. Souza ◽  
C. F. A. M. Penna ◽  
F. O. P. Leme ◽  
...  
Keyword(s):  
Seminal Plasma ◽  
Propidium Iodide ◽  
Acrosome Reaction ◽  
Fluorescent Microscopy ◽  
Calcium Ionophore ◽  
Peanut Agglutinin ◽  
Binding Assays ◽  
Frozen Semen ◽  
Fertilizing Ability

During cryopreservation and due to the large portion of seminal plasma removal, there is a decrease in equine sperm antioxidant protection. Lactoferrin and catalase in seminal plasma play an antioxidant role. The fertilizing ability of equine sperm has been analysed in vitro using sperm-zona binding assays with heterologous oocytes. The results have been correlated with in vivo fertility by means of acrosome reaction (AR) and the number of attached sperm to the zona pellucida (ZP). The aim of the present work was to estimate the potential fertilizing ability of stallion sperm frozen with INRA82 extender (Battelier et al. 1997) with lactoferrin and catalase, and after hyperactivation with procaine and calcium ionophore A-23187 (Ca-I) by determining the AR rate and number of attached sperm to the bovine ZP. Semen from 6 stallions was frozen with 3 extenders: (T1) control, INRA 82; (T2) T1 + 500 μg mL–1 lactoferrin; and (T3) T1 + 200 IU mL–1 catalase. After semen thawing, the sperm were selected by swim-up and distributed in 3 aliquots according to the hyperactivation treatments: (H1) control, after thawing; (H2) capacitating Whitten’s medium + 5 mM procaine chloride; and (H3) capacitating Whitten’s medium + 5 μM Ca-I. To the zona binding assays, bovine oocytes derived from abattoir ovaries were incubated at 38.5°C with 5% CO2 (1 h), and 5 oocytes were poured into each treatment droplet under mineral oil. Sperm were stained with Hoechst 33342 dye (35 μg mL–1), and after 2 h co-culture, the number of sperm attached to the ZP was determined with epi-fluorescent microscopy. The rate of sperm AR was determined after freezing-thawing (control) and hyperactivation treatments with propidium iodide and fluorescein isothiocyanate/peanut agglutinin dies with a flow cytometer. The green fluorescent (peanut agglutinin+) and not red stained (propidium iodide) sperm were considered acrosome reacted. Means of ZP attached sperm and percentage of AR sperm were analysed by ANOVA and Tukey test. A probability of P < 0.05 was considered significant. The mean of ZP attached sperm (4.2 ± 3.5) and AR sperm rate (4.4 ± 3.7%) did not differ among the extenders (P > 0.05). The rate of sperm AR after hyperactivation with procaine (5.2 ± 2.4%) did not differ to the Ca-I (6.1 ± 3.7%); however, they were higher than the spontaneous AR rate (1.1 ± 0.5%, P < 0.05). Lower number of ZP attached sperm was observed by the Ca-I induced hyperactivation protocol (1.9 ± 2.1) compared with the procaine (5.9 ± 3.7; P < 0.05), although they did not differ to the control (3.3 ± 2.7). In conclusion stallion frozen sperm were better hyperactivated with procaine than with Ca-I, and therefore, it is a more suitable sperm hyperactivation inductor to study equine IVF protocols with frozen semen. Acknowledgments are extended to CAPES, Brazil, for the financial support.

scholarly journals 106EVALUATION OF ADDITION OF REDUCED GLUTATHIONE TO COOLING MEDIUM ON IN VITRO FERTILITY AND ACROSOME REACTION IN BOAR SPERMATOZOA

2004 ◽  
Vol 16 (2) ◽  
pp. 175
Author(s):  
C. Matás ◽  
J. Gadea ◽  
F. García-Vázquez ◽  
J.C. Gardón ◽  
S. Cánovas
Keyword(s):  
In Vitro Fertilization ◽  
Acrosome Reaction ◽  
Reduced Glutathione ◽  
Membrane Integrity ◽  
Calcium Ionophore ◽  
Egg Yolk ◽  
Ros Generation ◽  
Vitro Fertilization ◽  
Cooling Medium

The process of cooling to 5°C prior to freezing produces physical and chemical stress on the sperm membrane associated with oxidative stress and reactive oxygen species (ROS) generation that reduces sperm viability and fertilizing ability. The addition of antioxidants to cooling medium could prevent the formation of ROS and improve the seminal parameters. The aim of these experiments was to investigate the effects of addition of reduced glutathione (GSH) to cooling extenders on (1) plasma membrane integrity, (2) acrosome reaction induction by ionophore A 23187 or progesterone, and (3) in vitro fertilization. Ejaculate-rich fractions from three mature pietrain boars were diluted in Beltsville Thaw Solution (BTS) extender and cooled to 15°C over 2h (group C). Thereafter, sperm were centrifuged and diluted in lactose/egg-yolk extender with 0mM (group 0), 1mM (group 1) or 5mM (group 5) of GSH, cooled to 5°C over 2h. The acrosome reaction was then induced by 1μM calcium ionophore or 10μM progesterone in TALP medium and incubated in 5% CO2, 38.5°C for 30 or 45min, respectively. Membrane integrity was evaluated by propidium iodide, and acrosomal status was monitored by means of FITC-labeled peanut agglutinin. Finally, in vitro fertilization was performed with these four spermatozoa groups as described previously (Matás et al. 2003 Reproduction 125, 133–141). ANOVA analysis revealed that the addition of GSH had no effect on the membrane integrity (ranged 58.8 to 66.9) or acrosome reaction induction (ranged 24.3 to 28.2, and 55.7 to 41.4 for progesterone and calcium ionophore, respectively). However, the results of the penetration assay revealed that the cooling affected the penetration rate and the number of sperm per oocyte (Table 1), and this assay is better than the others to predict changes in the spermatozoa functionality (Gadea J and Matás C 2000 Theriogenology 54, 1343–1357). In conclusion, the cooling process affects the in vitro fertilization, but the addition of GSH to the medium did not influence the parameters studied. Supported by AGL2000-0485-CO2-01. Table 1 Homologous in vitro penetration

Spermatozoa from a marsupial, the brushtail possum, contain β1,4-galactosyltransferase

2008 ◽  
Vol 20 (3) ◽  
pp. 402 ◽  
Author(s):  
A. G. Braundmeier ◽  
William G. Breed ◽  
D. J. Miller
Keyword(s):  
Molecular Weight ◽  
Zona Pellucida ◽  
Acrosome Reaction ◽  
Brushtail Possum ◽  
Laboratory Mice ◽  
Sperm Surface ◽  
Protein Functions ◽  
Sperm Acrosome Reaction ◽  
Porcine Spermatozoa ◽  
Egg Coat

β1,4-Galactosyltransferase-I (GalTase-I) is one of the key molecules on the sperm surface of eutherian mammals that is likely to be involved in binding to the egg coat, the zona pellucida, to mediate sperm–egg interaction. In laboratory mice, the species for which most data are available, this protein functions as a receptor for the zona pellucida protein ZP3 of the oocyte and, upon binding, triggers the sperm acrosome reaction. In the present study, we investigated the presence and abundance of GalTase-I in epididymal sperm extracts of a marsupial, the brushtail possum, Trichosurus vulpecula. For this, spermatozoa were collected from cauda epididymides and the amount of β1,4-galactosyltransferase activity in washed sperm extracts was compared with that of porcine spermatozoa. Overall β1,4-galactosyltransferase enzyme activity was found to be more abundant in possum sperm extracts than those from porcine spermatozoa (P < 0.05). Immunoblots with an antibody to mouse GalTase-I revealed that the molecular weight of possum spermatozoa GalTase-I was 66 kDa, which is similar to the molecular weight of GalTase-I in spermatozoa from eutherian mammals. The molecular weight of GalTase-I was the same in sperm extracts collected from the caput and cauda epididymides. These results demonstrate that GalTase-I is indeed present in possum spermatozoa and thus it may be a gamete receptor molecule on the sperm surface of marsupials as well as those of eutherian mammals.

Sign in / Sign up

Export Citation Format

Share Document