1
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Burgstaller SM, Auer KE, Rülicke T. A simple method for repeated in vivo sperm collection from laboratory mice. J Assist Reprod Genet 2024:10.1007/s10815-024-03201-x. [PMID: 39017771 DOI: 10.1007/s10815-024-03201-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 07/05/2024] [Indexed: 07/18/2024] Open
Abstract
PURPOSE Mouse spermatozoa for archiving laboratory mice or for in vitro fertilization (IVF) are routinely obtained from the cauda epididymis of adult males sacrificed for this purpose. To avoid the death of the donor, we tested whether a precisely timed interruption of the mating act could be used for repeated sperm collection from laboratory mice. METHODS Sperm donors (B6D2F1) were mated with a receptive female, and mating behavior was observed. The stud was separated from the female 1-2 s after the onset of the ejaculatory shudder. The ejected copulatory plug with the yellowish viscous ejaculate was carefully removed from the penile cup. RESULTS A total of 80 ejaculates were successfully obtained from 100 ejaculations. The latency to first mount was 1.1 ± 1.1 min (mean ± SD) and to ejaculation 8.1 ± 4.7 min. The average number of mounts to ejaculation was 10.5 ± 5.8, and the mean number of spermatozoa per collected ejaculate was 1.86 ± 1.05 × 106. An average fertilization rate of 76% was observed after IVF. CONCLUSIONS Separating the stud from the female just before ejaculation is feasible, easy to learn, and requires no special equipment. The sperm count of collected ejaculates is lower than natural ejaculations, but higher than previous in vivo sperm collection methods achieved. We recommend this simple sperm collection method in mice, especially when the donor cannot be sacrificed and/or repeated sperm collection from the same animal is required for experimental purposes.
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Affiliation(s)
- Sophie M Burgstaller
- Department of Biomedical Sciences and Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Kerstin E Auer
- Department of Biomedical Sciences and Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Thomas Rülicke
- Department of Biomedical Sciences and Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria.
- Ludwig Boltzmann Institute for Hematology and Oncology, Vienna, Austria.
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2
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Li Y, Wang H, Wang S, Zhang Q, Zhang H, Li T, Wang Q, Guo M, Feng H, Song Y, Wei G, Li J. Methylprednisolone improves the quality of liquid preserved boar spermatozoa in vitro and reduces polymorphonuclear neutrophil chemotaxis and phagocytosis. Front Vet Sci 2023; 10:1177873. [PMID: 37256001 PMCID: PMC10226469 DOI: 10.3389/fvets.2023.1177873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/18/2023] [Indexed: 06/01/2023] Open
Abstract
After artificial insemination, immune cells such as polymorphonuclear neutrophils will be recruited into the genital tract and induce endometrial inflammation, adversely affecting the spermatozoa. This study aimed to analyze the effect of methylprednisolone (MPS) on boar spermatozoa quality of in vitro liquid preservation and chemotaxis and phagocytosis of polymorphonuclear neutrophils toward boar spermatozoa. Various concentrations of MPS were added to the extender and analyzed for their effects on spermatozoa motility, kinetic parameters, abnormality rate, total antioxidant capacity (T-AOC) levels, H2O2 content, mitochondrial membrane potential and acrosome integrity. Testing of MPS on chemotaxis and phagocytosis of polymorphonuclear neutrophils toward spermatozoa induced by lipopolysaccharide (LPS). The results showed that an extender containing 2 × 10-7 mol/mL MPS was the most effective for preserving boar spermatozoa during in vitro liquid preservation at 17°C. It effectively improved spermatozoa motility, kinetic parameters, T-AOC levels, mitochondrial membrane potential and acrosome integrity, reducing the abnormality rate and H2O2 content. Meanwhile, the chemotaxis and phagocytosis of polymorphonuclear neutrophils toward spermatozoa under LPS induction were inhibited in a concentration-dependent manner. In conclusion, MPS has positive implications for improving in vitro liquid preserved boar spermatozoa quality, inhibiting chemotaxis and phagocytosis of polymorphonuclear neutrophils toward spermatozoa.
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3
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Balbach M, Rossetti T, Ferreira J, Ghanem L, Ritagliati C, Myers RW, Huggins DJ, Steegborn C, Miranda IC, Meinke PT, Buck J, Levin LR. On-demand male contraception via acute inhibition of soluble adenylyl cyclase. Nat Commun 2023; 14:637. [PMID: 36788210 PMCID: PMC9929232 DOI: 10.1038/s41467-023-36119-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 01/17/2023] [Indexed: 02/16/2023] Open
Abstract
Nearly half of all pregnancies are unintended; thus, existing family planning options are inadequate. For men, the only choices are condoms and vasectomy, and most current efforts to develop new contraceptives for men impact sperm development, meaning that contraception requires months of continuous pretreatment. Here, we provide proof-of-concept for an innovative strategy for on-demand contraception, where a man would take a birth control pill shortly before sex, only as needed. Soluble adenylyl cyclase (sAC) is essential for sperm motility and maturation. We show a single dose of a safe, acutely-acting sAC inhibitor with long residence time renders male mice temporarily infertile. Mice exhibit normal mating behavior, and full fertility returns the next day. These studies define sAC inhibitors as leads for on-demand contraceptives for men, and they provide in vivo proof-of-concept for previously untested paradigms in contraception; on-demand contraception after just a single dose and pharmacological contraception for men.
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Affiliation(s)
- Melanie Balbach
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Thomas Rossetti
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Jacob Ferreira
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Lubna Ghanem
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Carla Ritagliati
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Robert W Myers
- Tri-Institutional Therapeutics Discovery Institute, New York, NY, USA
| | - David J Huggins
- Tri-Institutional Therapeutics Discovery Institute, New York, NY, USA.,Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Clemens Steegborn
- Department of Biochemistry, University of Bayreuth, Bayreuth, Germany
| | - Ileana C Miranda
- Laboratory of Comparative Pathology, Weill Cornell Medicine, Memorial Sloan Kettering Cancer Center, and The Rockefeller University, New York, NY, USA
| | - Peter T Meinke
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA.,Tri-Institutional Therapeutics Discovery Institute, New York, NY, USA
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA.
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
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4
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Smirnov GY. Sperm Motility in Bank (Clethrionomys glareolus) and Northern Red-backed Voles (Cl. rutilus) Exposed to Industrial Pollution. RUSS J ECOL+ 2022. [DOI: 10.1134/s1067413622010106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Ded L, Chung JJ. Collection of in vivo Capacitated Sperm from Different Locations Along the Reproductive Tract of Time-Mated Female Mice by Microdissection. Bio Protoc 2021; 11:e4193. [PMID: 34761066 PMCID: PMC8554814 DOI: 10.21769/bioprotoc.4193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
Mammalian sperm cells are not capable of fertilizing an egg immediately after ejaculation; instead, they must gradually acquire the capacity to fertilize while they travel inside the female reproductive tract. Sperm cells are transported by the muscular activity of the myometrium to the utero-tubal junction (UTJ) before entering the oviduct where they undergo this physiological process, termed capacitation. Since the successful emulation of mammalian sperm capacitation in vitro, which led to the development of in vitro fertilization techniques, sperm capacitation and gamete interaction studies have been mostly carried out under in vitro conditions. Sperm cells are typically incubated in vitro for up to several hours at a concentration of more than 1 million cells per milliliter in the capacitation media inside a 37°C incubator with 5% CO2, mimicking the tubal fluid composed of serum albumin, bicarbonate, and Ca2+. The resultant sperm are functionally and molecularly heterogeneous with respect to acrosome reaction, motility, and phosphorylation. By contrast, in vivo sperm capacitation occurs in a time- and space-dependent manner, with limits on the number of capacitating sperm in the oviduct. The small number of sperm at the fertilization site in vivo are highly homogeneous and uniformly capable of fertilization. This discrepancy makes the degree of correlation between the changes observed from in vitro capacitation as a population average and the fertilizing capacity of sperm less clear. To overcome this issue, we used CLARITY tissue clearing to visualize sperm directly inside the female tract in situ and isolated sperm capacitated in vivo from the oviducts of the female mice after timed mating (
Ded et al., 2020
). Here, we present a step-by-step protocol to collect in vivo capacitated sperm by detailing a microdissection technique and subsequent preparation steps for fluorescent imaging. The advantage of the microdissection technique over in vitro capacitation is the ability to collect physiologically segregated, homogeneous sperm populations at different stages of capacitation. Compared to CLARITY, this technique is more straightforward and compatible with a broader spectrum of antibodies for downstream imaging studies, as it allows the researcher to avoid a potentially high background from non-sperm cells in the tissue. The disadvantage of this technique is the potential contamination of the isolated sperm from different regions of the oviduct and disruption of the fine molecular structures (e.g., CatSper nanodomains) during sperm isolation, especially when the preparation is not performed swiftly. Hence, we suggest that the combination of both in situ and ex vivo isolated sperm imaging is the best way how to address the molecular features of in vivo capacitated sperm.
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Affiliation(s)
- Lukas Ded
- Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, USA.,Laboratory of Reproductive Biology, Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic
| | - Jean-Ju Chung
- Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, USA.,Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, USA
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6
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Ferreira JJ, Lybaert P, Puga-Molina LC, Santi CM. Conserved Mechanism of Bicarbonate-Induced Sensitization of CatSper Channels in Human and Mouse Sperm. Front Cell Dev Biol 2021; 9:733653. [PMID: 34650979 PMCID: PMC8505895 DOI: 10.3389/fcell.2021.733653] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022] Open
Abstract
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.
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Affiliation(s)
- Juan J Ferreira
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States.,Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Pascale Lybaert
- Research Laboratory on Human Reproduction, Faculté de Médecine, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Lis C Puga-Molina
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States
| | - Celia M Santi
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, United States.,Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
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7
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Zigo M, Maňásková-Postlerová P, Zuidema D, Kerns K, Jonáková V, Tůmová L, Bubeníčková F, Sutovsky P. Porcine model for the study of sperm capacitation, fertilization and male fertility. Cell Tissue Res 2020; 380:237-262. [PMID: 32140927 DOI: 10.1007/s00441-020-03181-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 01/28/2020] [Indexed: 12/12/2022]
Abstract
Mammalian fertilization remains a poorly understood event with the vast majority of studies done in the mouse model. The purpose of this review is to revise the current knowledge about semen deposition, sperm transport, sperm capacitation, gamete interactions and early embryonic development with a focus on the porcine model as a relevant, alternative model organism to humans. The review provides a thorough overview of post-ejaculation events inside the sow's reproductive tract including comparisons with humans and implications for human fertilization and assisted reproductive therapy (ART). Porcine methodology for sperm handling, preservation, in vitro capacitation, oocyte in vitro maturation, in vitro fertilization and intra-cytoplasmic sperm injection that are routinely used in pig research laboratories can be successfully translated into ART to treat human infertility. Last, but not least, new knowledge about mitochondrial inheritance in the pig can provide an insight into human mitochondrial diseases and new knowledge on polyspermy defense mechanisms could contribute to the development of new male contraceptives.
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Affiliation(s)
- Michal Zigo
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Pavla Maňásková-Postlerová
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, 25250, Vestec, Czech Republic.,Department of Veterinary Sciences, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 16521, Prague, Czech Republic
| | - Dalen Zuidema
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Karl Kerns
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Věra Jonáková
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, 25250, Vestec, Czech Republic
| | - Lucie Tůmová
- Department of Veterinary Sciences, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 16521, Prague, Czech Republic
| | - Filipa Bubeníčková
- Department of Veterinary Sciences, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 16521, Prague, Czech Republic
| | - Peter Sutovsky
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65211, USA.,Department of Obstetrics, Gynecology & Women's Health, University of Missouri, Columbia, MO, 65211, USA
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8
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Brown SG, Publicover SJ, Barratt CLR, Martins da Silva SJ. Human sperm ion channel (dys)function: implications for fertilization. Hum Reprod Update 2019; 25:758-776. [PMID: 31665287 PMCID: PMC6847974 DOI: 10.1093/humupd/dmz032] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 07/14/2019] [Accepted: 08/13/2019] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Intensive research on sperm ion channels has identified members of several ion channel families in both mouse and human sperm. Gene knock-out studies have unequivocally demonstrated the importance of the calcium and potassium conductances in sperm for fertility. In both species, the calcium current is carried by the highly complex cation channel of sperm (CatSper). In mouse sperm, the potassium current has been conclusively shown to be carried by a channel consisting of the pore forming subunit SLO3 and auxiliary subunit leucine-rich repeat-containing 52 (LRRC52). However, in human sperm it is controversial whether the pore forming subunit of the channel is composed of SLO3 and/or SLO1. Deciphering the role of the proton-specific Hv1 channel is more challenging as it is only expressed in human sperm. However, definitive evidence for a role in, and importance for, human fertility can only be determined through studies using clinical samples. OBJECTIVE AND RATIONALE This review aims to provide insight into the role of sperm ion channels in human fertilization as evidenced from recent studies of sperm from infertile men. We also summarize the key discoveries from mouse ion channel knock-out models and contrast the properties of mouse and human CatSper and potassium currents. We detail the evidence for, and consequences of, defective ion channels in human sperm and discuss hypotheses to explain how defects arise and why affected sperm have impaired fertilization potential. SEARCH METHODS Relevant studies were identified using PubMed and were limited to ion channels that have been characterized in mouse and human sperm. Additional notable examples from other species are included as appropriate. OUTCOMES There are now well-documented fundamental differences between the properties of CatSper and potassium channel currents in mouse and human sperm. However, in both species, sperm lacking either channel cannot fertilize in vivo and CatSper-null sperm also fail to fertilize at IVF. Sperm-lacking potassium currents are capable of fertilizing at IVF, albeit at a much lower rate. However, additional complex and heterogeneous ion channel dysfunction has been reported in sperm from infertile men, the causes of which are unknown. Similarly, the nature of the functional impairment of affected patient sperm remains elusive. There are no reports of studies of Hv1 in human sperm from infertile men. WIDER IMPLICATIONS Recent studies using sperm from infertile men have given new insight and critical evidence supporting the supposition that calcium and potassium conductances are essential for human fertility. However, it should be highlighted that many fundamental questions remain regarding the nature of molecular and functional defects in sperm with dysfunctional ion channels. The development and application of advanced technologies remains a necessity to progress basic and clinical research in this area, with the aim of providing effective screening methodologies to identify and develop treatments for affected men in order to help prevent failed ART cycles. Conversely, development of drugs that block calcium and/or potassium conductances in sperm is a plausible strategy for producing sperm-specific contraceptives.
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Affiliation(s)
- Sean G Brown
- School of Applied Sciences, Abertay University, Dundee DD11HG, UK
| | | | - Christopher L R Barratt
- Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
| | - Sarah J Martins da Silva
- Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD19SY, UK
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9
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Arai Y, Sakase M, Fukushima M, Harayama H. Identification of isoforms of calyculin A-sensitive protein phosphatases which suppress full-type hyperactivation in bull ejaculated spermatozoa. Theriogenology 2019; 129:46-53. [PMID: 30798082 DOI: 10.1016/j.theriogenology.2019.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 01/04/2019] [Accepted: 02/10/2019] [Indexed: 01/04/2023]
Abstract
In bull spermatozoa, extracellular Ca2+-dependent full-type hyperactivation, which is characterized by the asymmetrical beating in whole parts of the middle/principal pieces, is suppressed by calyculin A-sensitive protein phosphatases. The aim of this study was to identify isoforms of these protein phosphatases. Ejaculated spermatozoa were used for the investigation on effects of protein phosphatase inhibitors (calyculin A with high specificity for both of protein phosphatases 1 and 2A, and okadaic acid with relatively higher specificity for protein phosphatase 2A than protein phosphatase 1) on the induction of extracellular Ca2+-dependent full-type hyperactivation by incubation with CaCl2 and cAMP analog (cBiMPS). They were also used for the immunodetection of protein phosphatases 1α, 1β, 1γ, 2Aα and 2Aβ. Percentages of full-type hyperactivated spermatozoa significantly increased after incubation with calyculin A (10 nM) in a concentration-dependent manner of CaCl2 (0-3.42 mM), though only minor increases in the percentages of full-type hyperactivated spermatozoa were observed after incubation with okadaic acid (10 nM). Moreover, the immunodetection of protein phosphatase isoforms showed sperm connecting piece and flagellum included protein phosphatases 1α and 1γ, but did not do the other isoforms. These results suggest that calyculin A-sensitive and okadaic acid-less sensitive protein phosphatases (1α and 1γ) are suppressors for the extracellular Ca2+-dependent full-type hyperactivation in bull ejaculated spermatozoa.
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Affiliation(s)
- Yuka Arai
- Laboratory of Reproductive Biology, Division of Animal Science, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Japan
| | - Mitsuhiro Sakase
- Hokubu Agricultural Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Japan
| | - Moriyuki Fukushima
- Hokubu Agricultural Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Japan
| | - Hiroshi Harayama
- Laboratory of Reproductive Biology, Division of Animal Science, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Japan.
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10
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Harayama H. Flagellar hyperactivation of bull and boar spermatozoa. Reprod Med Biol 2018; 17:442-448. [PMID: 30377397 PMCID: PMC6194283 DOI: 10.1002/rmb2.12227] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND In mammals, flagellar hyperactivation is indispensable to sperm fertilization with oocytes in vivo, although there are species differences in regulatory mechanisms for this event. In this study, I reviewed researches regarding hyperactivation of bull and boar spermatozoa, in comparison with those of spermatozoa from other species. METHODS Recent publications regarding sperm hyperactivation were collected and summarized. RESULTS MAIN FINDINGS In bull and boar spermatozoa, there are two types of hyperactivation "full-type hyperactivation and nonfull-type hyperactivation" which are equivalent to anti-hock hyperactivation and pro-hock hyperactivation of mouse spermatozoa, respectively, on the basis of the flagellar parts exhibiting asymmetrical beating. Full-type hyperactivation is initiated in response to a rapid increase of cytoplasmic Ca2+ in the connecting/middle and principal pieces by the mobilization of this divalent ion from extracellular space and internal store through cation channels. Regulatory molecules for the increase of cytoplasmic Ca2+ in the connecting/middle pieces are probably different from those in the principal pieces. CONCLUSION I have proposed a hypothesis on the regulation of full-type hyperactivation by the distinct signaling cascades leading to the increase in cytoplasmic Ca2+ between the connecting/middle and principal pieces of bull and boar spermatozoa.
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Affiliation(s)
- Hiroshi Harayama
- Division of Animal Science, Department of Bioresource Science, Graduate School of Agricultural ScienceKobe UniversityKobeJapan
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11
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Park YJ, Battistone MA, Kim B, Breton S. Relative contribution of clear cells and principal cells to luminal pH in the mouse epididymis. Biol Reprod 2018; 96:366-375. [PMID: 28203710 DOI: 10.1095/biolreprod.116.144857] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/06/2016] [Accepted: 01/04/2017] [Indexed: 12/27/2022] Open
Abstract
While spermatozoa undergo epididymal maturation, they remain quiescent thanks to the establishment of a low luminal pH. This study is aimed at determining how epithelial cells lining the epididymal lumen work together to maintain and regulate this acidic milieu. In particular, we examined the relative contribution of clear cells (CCs) and principal cells (PCs) to this process. Functional analysis in the mouse cauda epididymidis (Cd) perfused in vivo showed that the pH of a control solution remained constant at pH 6.6 after perfusion through the Cd lumen. In contrast, the pH of both an acidic (pH 5.8) and alkaline (pH 7.8) perfusate was progressively restored toward the control acidic pH. Pharmacological studies indicated the contribution of cystic fibrosis transmembrane regulator, previously shown to be present in the apical membrane of PCs, to the recovery from an acidic pH of 5.8. In addition, we found that CCs and PCs equally contribute to the recovery from an alkaline of 7.8, via the H+ pumping vacuolar ATPase (V-ATPase) located in CCs, and the Na+/H+ exchanger type 3 (NHE3) located in PCs. Immunofluorescence labeling showed apical membrane accumulation of the V-ATPase in CCs at pH 7.8, and its internalization at pH 5.8 compared to pH 6.6. Immunofluorescence showed expression of NHE3, but absence of NHE2, in PCs located in the Cd. RT-PCR and western blotting showed expression of NHE3 in all epididymal regions. Luminal 8-(4-chlorophenylthio)adenosine 3΄,5΄-cyclic monophosphate (cpt-cAMP) partially inhibited luminal pH recovery from pH 7.8. However, cpt-cAMP induced an increase in V-ATPase apical membrane accumulation at this pH. Cell fractionation studies showed the apical accumulation of NHE3 from intracellular vesicles at pH 7.8 versus 6.6, and prevention of this effect by cpt-cAMP. These results indicate the participation of both CCs and PCs in the regulation of luminal pH in the epididymis. Our study also shows the dual role of PCs in HCO3− and H+ secretion, and that this switch from base to acid secretion depends on the luminal environment. Characterization of the respective roles of CCs and PCs in the regulation of the optimal luminal condition for epididymal sperm maturation should provide new frameworks for the evaluation and treatment of male infertility.
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Affiliation(s)
- Yoo-Jin Park
- Department of Laboratory Medicine,College of Medicine,The Catholic University of Korea,Seoul,Republic of Korea
| | - Maria Agustina Battistone
- Instituto de Biología y Medicina Experimental (IByME-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Bongki Kim
- Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Korea.,Division of Biomedical Engineering, Hankuk University of Foreign Studies, Yongin, Korea
| | - Sylvie Breton
- Lesieur, R&D Center ESPCI ParisTech - CNRS, Coudekerque-Branche, France
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12
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Lishko PV, Mannowetz N. CatSper: A Unique Calcium Channel of the Sperm Flagellum. CURRENT OPINION IN PHYSIOLOGY 2018; 2:109-113. [PMID: 29707693 DOI: 10.1016/j.cophys.2018.02.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
To overcome egg protective vestments and ensure successful fertilization, mammalian spermatozoa switch symmetrical progressive motility to a powerful, whip-like flagellar motion, known as hyperactivation. The latter is triggered by a calcium influx through the sperm-specific, voltage-dependent, and alkalization-activated calcium channel of sperm - CatSper. The channel comprises nine subunits which together form a heteromeric complex. CatSper-deficient male mice and men with mutations in CatSper genes are infertile. This calcium channel is regulated by various endogenous compounds, such as steroids, prostaglandins, endocannabinoids, and intracellular pH. Being a sperm-specific ion channel that is not expressed anywhere else in the body, CatSper represents an ideal target for the development of female and even male contraceptives. In this review, we discuss the recent advances in studying CatSper functional properties and discuss future steps that are required to take in order to achieve a deep understanding of the molecular basis of CatSper function.
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Otsuka N, Harayama H. Characterization of extracellular Ca 2+ -dependent full-type hyperactivation in ejaculated boar spermatozoa preincubated with a cAMP analog. Mol Reprod Dev 2017; 84:1203-1217. [PMID: 28981180 DOI: 10.1002/mrd.22921] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 12/20/2022]
Abstract
Ejaculated boar spermatozoa exhibit two types of hyperactivation: full and non-full. Full-type hyperactivation is characterized by the asymmetrical bending of the entire middle piece-principal piece and a twisting/figure-eight-like trajectory, and can be induced by simple incubation with CaCl2 after preincubation with a cAMP analog (Sp-5,6-dichloro-1-β-D-ribofuranosyl-benzimidazole-3',5'-cyclic monophosphorothioate [cBiMPS]). Here, we compared the sperm flagellar motility after treatments with elevators of [Ca2+ ]i (cBiMPS/CaCl2 , thimerosal, procaine, and 4-aminopyridine) to characterize the regulatory mechanism of extracellular Ca2+ -dependent, full-type hyperactivation in ejaculated boar spermatozoa, and examined the possible involvement of Transient receptor potential cation channel subfamily C member 3 (TRPC3) in this event using the specific inhibitor Pyr3. Full-type hyperactivation was induced by a 60-min incubation with CaCl2 following a 180-min preincubation with cBiMPS but without Ca2+ . Thimerosal-treated spermatozoa exhibited full-type hyperactivation in a manner independent of extracellular Ca2+ ; conversely, this was not observed in procaine- or 4-aminopyridine-treated spermatozoa. A 20-min treatment with Pyr3 between preincubation with cBiMPS and incubation with CaCl2 , significantly suppressed the normal phenotype. These observations indicated that mechanisms underlying full-type hyperactivation in spermatozoa incubated with CaCl2 after preincubation with cBiMPS are different from those in the thimerosal-treated spermatozoa. Furthermore, indirect immunofluorescence localized TRPC3 in the upper segment of the middle piece, which bends asymmetrically during full-type hyperactivation but not in non-full-type hyperactivation, suggesting that TRPC3 may be involved in the extracellular Ca2+ -dependent full-type hyperactivation in ejaculated boar spermatozoa.
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Affiliation(s)
- Nagisa Otsuka
- Laboratory of Reproductive Biology, Division of Animal Science, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Hiroshi Harayama
- Laboratory of Reproductive Biology, Division of Animal Science, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
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Comparison of different extenders on the recovery and longevity of epididymal sperm from Spix's yellow-toothed cavies (Galea spixii Wagler, 1831). ZYGOTE 2017; 25:176-182. [DOI: 10.1017/s0967199417000016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SummaryThe aim of this study was to evaluate the performance of cavy (Galea spixii) epididymal sperm following addition to TES or TRIS extenders and using a thermal resistance test (TRT), as well as fluorescence analysis as a complementary method to predict the viability of these gametes. Nine testicle–epididymis complexes were used for sperm collection using a flotation method. Epididymis tails were sliced and one was immersed in 3 ml of TRIS buffer, and the other in 3 ml of TES, for 5 min. After sperm recovery, the samples were subjected to a TRT which involved incubation in a water bath at 37°C for 3 h. During incubation, sample parameters were assessed at 0, 15, 30, 60, 90, 120, 150 or 180 min intervals. Results indicated that the TRIS diluent was more efficient than TES (P < 0.05) for the maintenance of sperm parameters in Spix's yellow-toothed cavies over the whole TRT, maintaining sperm longevity for an extended time. In conclusion, we indicate the use of TRIS diluent for recovery and maintenance of longevity of epididymal sperm from cavies (G. spixii).
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15
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Chung JJ, Miki K, Kim D, Shim SH, Shi HF, Hwang JY, Cai X, Iseri Y, Zhuang X, Clapham DE. CatSperζ regulates the structural continuity of sperm Ca 2+ signaling domains and is required for normal fertility. eLife 2017; 6. [PMID: 28226241 PMCID: PMC5362262 DOI: 10.7554/elife.23082] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/20/2017] [Indexed: 12/16/2022] Open
Abstract
We report that the Gm7068 (CatSpere) and Tex40 (CatSperz) genes encode novel subunits of a 9-subunit CatSper ion channel complex. Targeted disruption of CatSperz reduces CatSper current and sperm rheotactic efficiency in mice, resulting in severe male subfertility. Normally distributed in linear quadrilateral nanodomains along the flagellum, the complex lacking CatSperζ is disrupted at ~0.8 μm intervals along the flagellum. This disruption renders the proximal flagellum inflexible and alters the 3D flagellar envelope, thus preventing sperm from reorienting against fluid flow in vitro and efficiently migrating in vivo. Ejaculated CatSperz-null sperm cells retrieved from the mated female uterus partially rescue in vitro fertilization (IVF) that failed with epididymal spermatozoa alone. Human CatSperε is quadrilaterally arranged along the flagella, similar to the CatSper complex in mouse sperm. We speculate that the newly identified CatSperζ subunit is a late evolutionary adaptation to maximize fertilization inside the mammalian female reproductive tract. DOI:http://dx.doi.org/10.7554/eLife.23082.001 Male mammals ejaculate millions of sperm cells each time they mate with a female. Only a few of these cells manage to travel up the female’s reproductive tract to reach the egg, and usually only one sperm fertilizes it. Freshly ejaculated sperm are incapable of fertilizing eggs and have to undergo several changes within the female to become able to do so. One crucial change occurs in the sperm tail, which starts to beat vigorously in a whip-like motion. This type of movement – known as hyperactivated motility – enables the sperm to swim towards the egg, push through a sticky coating that surrounds it, and then burrow into it. Hyperactivated motility is triggered when calcium ions enter the sperm cell via a specific channel protein known as CatSper, which is found in the membrane that surrounds the cell. CatSper channels form groups (known as complexes) with several other proteins that are arranged in a unique pattern of four straight ‘stripes’ running down the tail of the sperm. This arrangement is necessary for hyperactivated motility and mutations in the genes that encode these proteins can lead to infertility in males. The CatSper channel complex is known to contain seven proteins: four that form a pore through which calcium ions can enter, and three accessory proteins whose roles in hyperactivated motility are less clear. Chung et al. identified two genes in mice that encode new accessory proteins in the CatSper channel complex named CatSper epsilon and CatSper zeta. Further experiments analyzed the role of CatSper zeta in more detail. Mutant males that lack CatSper zeta have fragmented patterns of CatSper stripes in the tails of their sperm. Moreover, fewer calcium ions were able to pass through the channels to enter the cell. Together, this made the sperm tail more rigid, which prevented it from moving efficiently within the female, resulting in reduced fertility. Chung et al. also found that the mutant sperm were less able to penetrate the egg than normal sperm. During evolution, the gene that encodes CatSper zeta appeared first in mammals and may represent an adaptation that improved the chances of a sperm fertilizing the egg inside the reproductive tract of female mammals. Future challenges will be to explore how the CatSper channel assembles on the membrane of sperm and find out exactly how calcium ions trigger hyperactivated motility. DOI:http://dx.doi.org/10.7554/eLife.23082.002
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Affiliation(s)
- Jean-Ju Chung
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States.,Department of Neurobiology, Harvard Medical School, Boston, United States.,Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, United States
| | - Kiyoshi Miki
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States
| | - Doory Kim
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.,Department of Physics, Harvard University, Cambridge, United States
| | - Sang-Hee Shim
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.,Department of Physics, Harvard University, Cambridge, United States
| | - Huanan F Shi
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, United States
| | - Jae Yeon Hwang
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, United States
| | - Xinjiang Cai
- Department of Medicine, James J. Perters VA Bronx, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Yusuf Iseri
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States
| | - Xiaowei Zhuang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.,Department of Physics, Harvard University, Cambridge, United States
| | - David E Clapham
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States.,Department of Neurobiology, Harvard Medical School, Boston, United States
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Holden SA, Fernandez-Fuertes B, Murphy EM, Lonergan P, Fair S. Effect of seminal plasma from high- and low-fertility bulls on cauda epididymal sperm function. Reprod Fertil Dev 2017; 29:2457-2465. [DOI: 10.1071/rd17136] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 05/09/2017] [Indexed: 11/23/2022] Open
Abstract
The aim of this study was to characterise the effect of seminal plasma (SP) from bulls of high or low fertility on sperm function. First, the effect of SP on the motility of fresh cauda epididymal spermatozoa (CES) and frozen–thawed ejaculated spermatozoa was assessed (Experiment 1a). Seminal plasma was then collected from bulls of known high and low fertility. Pooled CES were incubated in the SP from each bull, diluted and assessed for motility and viability on Days 1, 2, 3 and 5 after packaging as fresh semen (Experiment 1b). Also assessed were motility, kinematics, viability and mitochondrial membrane potential after thawing (Experiment 1c) as well as hypotonic resistance (Experiment 2) and fertilisation potential using in vitro fertilisation (Experiment 3). Seminal plasma increased the motility of CES (P < 0.05); however, there was no effect of SP on the motility and viability of fresh CES or on CES post-thaw motility, viability and mitochondrial membrane potential (P > 0.05). The hypotonic resistance of CES was reduced by SP (P < 0.05), irrespective of whether the SP was from high- or low-fertility bulls. Seminal plasma from high- or low-fertility bulls had no effect on cleavage or blastocyst rates (P > 0.05). In conclusion, SP affects the physiological function of CES but there is no difference between SP from high- or low-fertility bulls.
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17
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Lindemann CB, Lesich KA. Functional anatomy of the mammalian sperm flagellum. Cytoskeleton (Hoboken) 2016; 73:652-669. [PMID: 27712041 DOI: 10.1002/cm.21338] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/21/2016] [Accepted: 10/05/2016] [Indexed: 12/20/2022]
Abstract
The eukaryotic flagellum is the organelle responsible for the propulsion of the male gamete in most animals. Without exception, sperm of all mammalian species use a flagellum for swimming. The mammalian sperm has a centrally located 9 + 2 arrangement of microtubule doublets and hundreds of accessory proteins that together constitute an axoneme. However, they also possess several characteristic peri-axonemal structures that make the mammalian sperm tail function differently. These modifications include nine outer dense fibers (ODFs) that are paired with the nine outer microtubule doublets of the axoneme, and are anchored in a structure called the connecting piece located at the base. The presence of the ODFs and connecting piece, and the absence of a basal body, dictate that physical forces generated by the dynein motors are transmitted to the base of the flagellum through the ODFs. Mammalian sperm flagella also possess a mitochondrial and a fibrous sheath that encircle most of the axoneme. These sheaths and the ODFs add mechanical rigidity to the flagellum creating the functional effect of increasing bend wavelength, which requires the entrainment of more dynein motors in the production of a single wave. The sheaths also act as a retinaculum and maintain the integrity of the central axoneme when large bending torques are generated by dynein. Large torque production is crucial to the process of hyperactivation and the unique motility transitions associated with effective fertilizing capacity. Consequently, these specialized anatomical features are essential for the effective interaction of sperm with the female reproductive tract and ovum. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Kathleen A Lesich
- Department of Biological Sciences, Oakland University, Rochester, Michigan
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18
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Ben Slima A, Chtourou Y, Barkallah M, Fetoui H, Boudawara T, Gdoura R. Endocrine disrupting potential and reproductive dysfunction in male mice exposed to deltamethrin. Hum Exp Toxicol 2016; 36:218-226. [PMID: 27164926 DOI: 10.1177/0960327116646617] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Pesticide exposure may affect semen quality and male fertility in humans. The aim of the present work was to elucidate the adverse effects of deltamethrin (Delta), a synthetic pyrethroid, on exposed male mice and their offspring. Adult male Albino/Swiss mice received deltamethrin (5 mg/kg) daily for 35 days and mated with untreated females to produce offspring. Classical measurements of ejaculate and sperm quality and testicular histopathological changes were assessed. Deltamethrin treatment affects sperm quality and quantity in the ejaculated semen of mice that had also markedly impaired libido as measured by indices of mating and fertility and number of pregnant females housed with male mice exposed to this pesticide. Exposure mice to deltamethrin significantly decreased their testosterone and inhibin B levels and affected reproductive performance. Testes of exposed mice showed marked histopathological alterations as compared to the control group. The mice exposed to 5 mg/kg body weight/day of deltamethrin showed severe alterations of the seminiferous tubules, sloughing of the germ cells, the vacuolization of germ cell cytoplasm, and the disruption of spermatogenic cells compared to the control group. Altered pregnancy outcomes were directly attributed to damage of sperm of male mice exposed to deltamethrin compared to the control group. We concluded that exposure to deltamethrin affected the reproductive system of male mice explored by altered total sperm density, motility, and morphology in mice spermatozoa.
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Affiliation(s)
- A Ben Slima
- 1 Unit Research of Toxicology-Microbiology Environmental and Health, University of Sfax, Sfax, Tunisia
| | - Y Chtourou
- 1 Unit Research of Toxicology-Microbiology Environmental and Health, University of Sfax, Sfax, Tunisia
| | - M Barkallah
- 1 Unit Research of Toxicology-Microbiology Environmental and Health, University of Sfax, Sfax, Tunisia
| | - H Fetoui
- 1 Unit Research of Toxicology-Microbiology Environmental and Health, University of Sfax, Sfax, Tunisia
| | - T Boudawara
- 2 Anatomopathology Laboratory, University of Sfax, CHU Habib Bourguiba, Sfax, Tunisia
| | - R Gdoura
- 1 Unit Research of Toxicology-Microbiology Environmental and Health, University of Sfax, Sfax, Tunisia
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19
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Sutter A, Lindholm AK. Meiotic drive changes sperm precedence patterns in house mice: potential for male alternative mating tactics? BMC Evol Biol 2016; 16:133. [PMID: 27328665 PMCID: PMC4915163 DOI: 10.1186/s12862-016-0710-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/13/2016] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND With female multiple mating (polyandry), male-male competition extends to after copulation (sperm competition). Males respond to this selective pressure through physiological, morphological and behavioural adaptations. Sperm competitiveness is commonly decreased in heterozygote carriers of male meiotic drivers, selfish genetic elements that manipulate the production of gametes in males. This might give carriers an evolutionary incentive to reduce the risk of sperm competition. Here, we explore this possibility in house mice. Natural populations frequently harbour a well-characterised male driver (t haplotype), which is transmitted to 90 % of heterozygous (+/t) males' offspring. Previous research demonstrated strong detrimental effects on sperm competitiveness, and suggested that +/t males are particularly disadvantaged against wild type males when first-to-mate. Low paternity success in the first-to-mate role is expected to favour male adaptations that decrease the risk of sperm competition by preventing female remating. Genotype-specific paternity patterns (sperm precedence) could lead to genetically determined alternative reproductive tactics that can spread through gene level selection. Here, we seek confirmation that +/t males are generally disadvantaged when first-to-mate and address whether males of different genotypes differ in reproductive tactics (copulatory and morphological) to maximise individual or driver fitness. Finally, we attempt to explain the mechanistic basis for alternative sperm precedence patterns in this species. RESULTS We confirmed that +/t males are weak sperm competitors when first to mate. When two +/t males competed, the second-to-mate was more successful, which contrasts with first male sperm precedence when wild type males competed. However, we found no differences between male genotypes in reproductive behaviour or morphology that were consistent with alternative reproductive tactics. Sperm of +/+ and +/t males differed with respect to in vitro sperm features. Premature hypermotility in +/t males' sperm can potentially explain why +/t males are very weak sperm competitors when first-to-mate. CONCLUSIONS Our results demonstrate that meiotic drivers can have strong effects on sperm precedence patterns, and may provide a heritable basis for alternative reproductive tactics motivated by reduced sperm competitiveness. We discuss how experimental and evolutionary constraints may help explain why male genotypes did not show the predicted differences.
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Affiliation(s)
- Andreas Sutter
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
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20
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Tosti E, Ménézo Y. Gamete activation: basic knowledge and clinical applications. Hum Reprod Update 2016; 22:420-39. [PMID: 27278231 PMCID: PMC4917743 DOI: 10.1093/humupd/dmw014] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 04/01/2016] [Indexed: 01/07/2023] Open
Abstract
Background The first clues to the process of gamete activation date back to nearly 60 years ago. The mutual activation of gametes is a crucial event during fertilization. In the testis and ovaries, spermatozoa and oocytes are in a state of meiotic and metabolic quiescence and require reciprocal signals in order to undergo functional changes that lead to competence for fertilization. First, the oocyte activates sperm by triggering motility, chemoattraction, binding and the acrosome reaction, culminating with the fusion of the two plasma membranes. At the end of this cascade of events, collectively known as sperm capacitation, sperm-induced oocyte activation occurs, generating electrical, morphological and metabolic modifications in the oocyte. Objective and rationale The aim of this review is to provide the current state of knowledge regarding the entire process of gamete activation in selected specific animal models that have contributed to our understanding of fertilization in mammals, including humans. Here we describe in detail the reciprocal induction of the two activation processes, the molecules involved and the mechanisms of cell interaction and signal transduction that ultimately result in successful embryo development and creation of a new individual. Search methods We carried out a literature survey with no restrictions on publication date (from the early 1950s to March 2016) using PubMed/Medline, Google Scholar and Web of Knowledge by utilizing common keywords applied in the field of fertilization and embryo development. We also screened the complete list of references published in the most recent research articles and relevant reviews published in English (both animal and human studies) on the topics investigated. Outcomes Literature on the principal animal models demonstrates that gamete activation is a pre-requisite for successful fertilization, and is a process common to all species studied to date. We provide a detailed description of the dramatic changes in gamete morphology and behavior, the regulatory molecules triggering gamete activation and the intracellular ions and second messengers involved in active metabolic pathways in different species. Recent scientific advances suggest that artificial gamete activation may represent a novel technique to improve human IVF outcomes, but this approach requires caution. Wider implications Although controversial, manipulation of gamete activation represents a promising tool for ameliorating the fertilization rate in assisted reproductive technologies. A better knowledge of mechanisms that transform the quiescent oocyte into a pluripotent cell may also provide new insights for the clinical use of stem cells.
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Affiliation(s)
- Elisabetta Tosti
- Stazione Zoologica Anton Dohrn, Villa Comunale, Naples 80121, Italy
| | - Yves Ménézo
- London Fertility Associates, 104 Harley Street, London WIG7JD, UK
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