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Brisard BM, Cashwell KD, Stewart SM, Harrison LM, Charles AC, Dennis CV, Henslee IR, Carrow EL, Belcher HA, Bhowmick D, Vos P, Bier M, Hart DM, Schmidt CA. "Modeling Diffusive Search by Non-Adaptive Sperm: Empirical and Computational Insights". BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599386. [PMID: 38948799 PMCID: PMC11212867 DOI: 10.1101/2024.06.17.599386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
During fertilization, mammalian sperm undergo a winnowing selection process that reduces the candidate pool of potential fertilizers from ~106-1011 cells to 101-102 cells (depending on the species). Classical sperm competition theory addresses the positive or 'stabilizing' selection that acts on sperm phenotypes within populations of organisms but does not strictly address the developmental consequences of sperm traits among individual organisms that are under purifying selection during fertilization. It is the latter that is of utmost concern for improving assisted reproductive technologies (ART) because 'low fitness' sperm may be inadvertently used for fertilization during interventions that rely heavily on artificial sperm selection, such as intracytoplasmic sperm injection (ICSI). Importantly, some form of sperm selection is used in nearly all forms of ART (e.g., differential centrifugation, swim-up, or hyaluronan binding assays, etc.). To date, there is no unifying quantitative framework (i.e., theory of sperm selection) that synthesizes causal mechanisms of selection with observed natural variation in individual sperm traits. In this report, we reframe the physiological function of sperm as a collective diffusive search process and develop multi-scale computational models to explore the causal dynamics that constrain sperm 'fitness' during fertilization. Several experimentally useful concepts are developed, including a probabilistic measure of sperm 'fitness' as well as an information theoretic measure of the magnitude of sperm selection, each of which are assessed under systematic increases in microenvironmental selective pressure acting on sperm motility patterns.
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Affiliation(s)
| | | | | | | | | | | | - Ivie R. Henslee
- Department of Biology, East Carolina University, Greenville NC
| | - Ethan L. Carrow
- Department of Biology, East Carolina University, Greenville NC
| | - Heather A. Belcher
- Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University
| | - Debajit Bhowmick
- Flow Cytometry Core Facility, Brody School of Medicine, East Carolina University
| | - Paul Vos
- Department of Public Health, East Carolina University, Greenville NC
| | - Martin Bier
- Department of Physics, East Carolina University, Greenville NC
| | - David M. Hart
- Department of Computer Science, East Carolina University, Greenville, NC
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2
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Peña-Delgado V, Noya A, Carvajal-Serna M, Abecia JA, Pérez-Pe R, Casao A. Differential effect of melatonin on ram spermatozoa depending on the allelic variant of the RsaI polymorphism of the MTR1A gene, incubation medium and season. Reprod Fertil Dev 2024; 36:NULL. [PMID: 38905444 DOI: 10.1071/rd23233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 06/03/2024] [Indexed: 06/23/2024] Open
Abstract
Context The Rsa I polymorphism of the melatonin receptor MTNR1A gene affects seasonal reproduction in sheep, but its effect on ram spermatozoa and their response to melatonin is unknown. Aims This study aims to evaluate whether Rsa I polymorphism of the MTNR1A gene influences the response of ram spermatozoa to in vitro added melatonin. Methods Spermatozoa from rams carrying different Rsa I allelic variants were incubated with melatonin in a TALP medium or a capacitation-triggering medium during the reproductive and non-reproductive seasons. After incubation, sperm motility, membrane integrity, mitochondria activity, oxidative damage, apoptotic markers and capacitation status were assessed. Key results In the reproductive season, the T/T genotype was related to some adverse effects of melatonin when spermatozoa were incubated in TALP medium, whereas the C/C genotype was linked with adverse effects when the hormone was added in a capacitation-triggering medium. The decapacitating effect of melatonin on spermatozoa was also different depending on genotype. Conclusions The melatonin effect on spermatozoa from rams carrying different Rsa I genotypes differed depending on the season and the medium. Implications The knowledge of the Rsa I allelic variant of the MTNR1A gene of rams could be helpful when carrying out in vitro reproductive techniques in the ovine species.
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Affiliation(s)
- Victoria Peña-Delgado
- BIOFITER-IUCA, Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain
| | - Agustí Noya
- BIOFITER-IUCA, Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain
| | - Melissa Carvajal-Serna
- BIOFITER-IUCA, Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain
| | - José A Abecia
- BIOFITER-IUCA, Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain
| | - Rosaura Pérez-Pe
- BIOFITER-IUCA, Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain
| | - Adriana Casao
- BIOFITER-IUCA, Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain
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3
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Tufoni C, Battistella A, Luppi S, Boscolo R, Ricci G, Lazzarino M, Andolfi L. Flagellar beating forces of human spermatozoa with different motility behaviors. Reprod Biol Endocrinol 2024; 22:28. [PMID: 38448984 PMCID: PMC10916019 DOI: 10.1186/s12958-024-01197-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 02/13/2024] [Indexed: 03/08/2024] Open
Abstract
BACKGROUND One of the causes of male infertility is associated with altered spermatozoa motility. These sperm features are frequently analyzed by image-based approaches, which, despite allowing the acquisition of crucial parameters to assess sperm motility, they are unable to provide details regarding the flagellar beating forces, which have been neglected until now. RESULTS In this work we exploit Fluidic Force Microscopy to investigate and quantify the forces associated with the flagellar beating frequencies of human spermatozoa. The analysis is performed on two groups divided according to the progressive motility of semen samples, as identified by standard clinical protocols. In the first group, 100% of the spermatozoa swim linearly (100% progressive motility), while, in the other, spermatozoa show both linear and circular motility (identified as 80 - 20% progressive motility). Significant differences in flagellar beating forces between spermatozoa from semen sample with different progressive motility are observed. Particularly, linear motile spermatozoa exhibit forces higher than those with a circular movement. CONCLUSIONS This research can increase our understanding of sperm motility and the role of mechanics in fertilization, which could help us unveil some of the causes of idiopathic male infertility.
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Affiliation(s)
- Cristina Tufoni
- University of Trieste, Trieste, 34100, Italy
- CNR-Istituto Officina dei Materiali (IOM), SS 14 km 163.5 Area Science Park Basovizza, Trieste, 34149, Italy
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Alice Battistella
- CNR-Istituto Officina dei Materiali (IOM), SS 14 km 163.5 Area Science Park Basovizza, Trieste, 34149, Italy
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Stefania Luppi
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Rita Boscolo
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy
| | - Giuseppe Ricci
- Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy.
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy.
| | - Marco Lazzarino
- CNR-Istituto Officina dei Materiali (IOM), SS 14 km 163.5 Area Science Park Basovizza, Trieste, 34149, Italy
| | - Laura Andolfi
- CNR-Istituto Officina dei Materiali (IOM), SS 14 km 163.5 Area Science Park Basovizza, Trieste, 34149, Italy.
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4
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Schmidt CA, Hale BJ, Bhowmick D, Miller WJ, Neufer PD, Geyer CB. Pyruvate modulation of redox potential controls mouse sperm motility. Dev Cell 2024; 59:79-90.e6. [PMID: 38101411 PMCID: PMC10872278 DOI: 10.1016/j.devcel.2023.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 06/21/2023] [Accepted: 11/13/2023] [Indexed: 12/17/2023]
Abstract
Sperm gain fertilization competence in the female reproductive tract through a series of biochemical changes and a requisite switch from linear progressive to hyperactive motility. Despite being essential for fertilization, regulation of sperm energy transduction is poorly understood. This knowledge gap confounds interpretation of interspecies variation and limits progress in optimizing sperm selection for assisted reproduction. Here, we developed a model of mouse sperm bioenergetics using metabolic phenotyping data, quantitative microscopy, and spectral flow cytometry. The results define a mechanism of motility regulation by microenvironmental pyruvate. Rather than being consumed as a mitochondrial fuel source, pyruvate stimulates hyperactivation by repressing lactate oxidation and activating glycolysis in the flagellum through provision of nicotinamide adenine dinucleotide (NAD)+. These findings provide evidence that the transitions in motility requisite for sperm competence are governed by changes in the metabolic microenvironment, highlighting the unexplored potential of using catabolite combination to optimize sperm selection for fertilization.
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Affiliation(s)
- Cameron A Schmidt
- Department of Biology at East Carolina University, Greenville, NC 27858, USA; East Carolina Diabetes and Obesity Institute at East Carolina University, Greenville, NC 27834, USA.
| | - Benjamin J Hale
- East Carolina Diabetes and Obesity Institute at East Carolina University, Greenville, NC 27834, USA; Department of Anatomy and Cell Biology, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA
| | - Debajit Bhowmick
- Flow Cytometry Core Facility, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA
| | - William J Miller
- Department of Engineering, East Carolina University, Greenville, NC 27834, USA
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute at East Carolina University, Greenville, NC 27834, USA; Department of Physiology, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA
| | - Christopher B Geyer
- East Carolina Diabetes and Obesity Institute at East Carolina University, Greenville, NC 27834, USA; Department of Anatomy and Cell Biology, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA.
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Powar S, Parast FY, Nandagiri A, Gaikwad AS, Potter DL, O'Bryan MK, Prabhakar R, Soria J, Nosrati R. Unraveling the Kinematics of Sperm Motion by Reconstructing the Flagellar Wave Motion in 3D. SMALL METHODS 2022; 6:e2101089. [PMID: 35138044 DOI: 10.1002/smtd.202101089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Sperm swim through the female reproductive tract by propagating a 3D flagellar wave that is self-regulatory in nature and driven by dynein motors. Traditional microscopy methods fail to capture the full dynamics of sperm flagellar activity as they only image and analyze sperm motility in 2D. Here, an automated platform to analyze sperm swimming behavior in 3D by using thin-lens approximation and high-speed dark field microscopy to reconstruct the flagellar waveform in 3D is presented. It is found that head-tethered mouse sperm exhibit a rolling beating behavior in 3D with the beating frequency of 6.2 Hz using spectral analysis. The flagellar waveform bends in 3D, particularly in the distal regions, but is only weakly nonplanar and ambidextrous in nature, with the local helicity along the flagellum fluctuating between clockwise and counterclockwise handedness. These findings suggest a nonpersistent flagellar helicity. This method provides new opportunities for the accurate measurement of the full motion of eukaryotic flagella and cilia which is essential for a biophysical understanding of their activation by dynein motors.
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Affiliation(s)
- Sushant Powar
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Farin Yazdan Parast
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Ashwin Nandagiri
- IITB-Monash Research Academy, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Avinash S Gaikwad
- School of BioSciences, Faculty of Science, University of Melbourne, Parkville, Victoria, 3010, Australia
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - David L Potter
- Monash Micro-Imaging, Monash University, Clayton, Victoria, 3800, Australia
| | - Moira K O'Bryan
- School of BioSciences, Faculty of Science, University of Melbourne, Parkville, Victoria, 3010, Australia
- School of Biological Sciences, Monash University, Clayton, Victoria, 3800, Australia
| | - Ranganathan Prabhakar
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Julio Soria
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, 3800, Australia
- Laboratory for Turbulence Research in Aerospace & Combustion (LTRAC), Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Reza Nosrati
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, 3800, Australia
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6
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Mammalian sperm hyperactivation regulates navigation via physical boundaries and promotes pseudo-chemotaxis. Proc Natl Acad Sci U S A 2021; 118:2107500118. [PMID: 34716265 DOI: 10.1073/pnas.2107500118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/27/2021] [Indexed: 11/18/2022] Open
Abstract
Mammalian sperm migration within the complex and dynamic environment of the female reproductive tract toward the fertilization site requires navigational mechanisms, through which sperm respond to the tract environment and maintain the appropriate swimming behavior. In the oviduct (fallopian tube), sperm undergo a process called "hyperactivation," which involves switching from a nearly symmetrical, low-amplitude, and flagellar beating pattern to an asymmetrical, high-amplitude beating pattern that is required for fertilization in vivo. Here, exploring bovine sperm motion in high-aspect ratio microfluidic reservoirs as well as theoretical and computational modeling, we demonstrate that sperm hyperactivation, in response to pharmacological agonists, modulates sperm-sidewall interactions and thus navigation via physical boundaries. Prior to hyperactivation, sperm remained swimming along the sidewalls of the reservoirs; however, once hyperactivation caused the intrinsic curvature of sperm to exceed a critical value, swimming along the sidewalls was reduced. We further studied the effect of noise in the intrinsic curvature near the critical value and found that these nonthermal fluctuations yielded an interesting "Run-Stop" motion on the sidewall. Finally, we observed that hyperactivation produced a "pseudo-chemotaxis" behavior, in that sperm stayed longer within microfluidic chambers containing higher concentrations of hyperactivation agonists.
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7
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Sacha CR, Vagios S, Hammer K, Fitz V, Souter I, Bormann CL. The effect of semen collection location and time to processing on sperm parameters and early IVF/ICSI outcomes. J Assist Reprod Genet 2021; 38:1449-1457. [PMID: 33704628 PMCID: PMC7946618 DOI: 10.1007/s10815-021-02128-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/23/2021] [Indexed: 11/02/2022] Open
Abstract
PURPOSE We aimed to assess whether home collection and increased time to semen processing are associated with altered sperm parameters, fertilization rates (FR), day 5 usable quality blastocyst development rates (D5-UQBR), or pregnancy rates (PR) in patients undergoing IVF/ICSI. METHODS This was a retrospective cohort study of patients undergoing IVF/ICSI before the coronavirus disease 2019 (COVID-19) pandemic ("clinic" collection, n = 119) and after COVID-19 ("home" collection, n = 125) at an academic fertility practice. Home collection occurred within 2 h of semen processing. Patient sperm parameters, FR (#2PN/MII), D5-UQBR (# transferable and freezable quality blastocysts/# 2PN), and PR in fresh transfer cycles were compared between clinic and home groups with t-tests. The association between time to processing on outcomes was assessed with regression modeling, controlling for potential confounders. RESULTS Mean male age was 37.9 years in the clinic group and 37.2 years in the home group (p = 0.380). On average, men were abstinent for 3.0 days (SD 1.7) in the clinic group and 4.1 days (SD 5.4) in the home group (p = 0.028). Mean time to semen processing was 35.7 min (SD 9.4) in the clinic group and 82.6 min (SD 33.8) in the home group (p < 0.001). There was no association between collection location and increased time to processing on sperm motility, total motile count, FR, D5-UQBR, or PR. CONCLUSIONS Our data suggest that increased time to processing up to 2 h with home semen collection does not negatively impact sperm parameters or early IVF/ICSI outcomes.
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Affiliation(s)
- Caitlin R Sacha
- Massachusetts General Hospital Fertility Center, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology, and Reproductive Biology, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street-Yawkey 10A, Boston, MA, 02114, USA.
| | - Stylianos Vagios
- Massachusetts General Hospital Fertility Center, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology, and Reproductive Biology, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street-Yawkey 10A, Boston, MA, 02114, USA
| | - Karissa Hammer
- Massachusetts General Hospital Fertility Center, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology, and Reproductive Biology, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street-Yawkey 10A, Boston, MA, 02114, USA
| | - Victoria Fitz
- Massachusetts General Hospital Fertility Center, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology, and Reproductive Biology, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street-Yawkey 10A, Boston, MA, 02114, USA
| | - Irene Souter
- Massachusetts General Hospital Fertility Center, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology, and Reproductive Biology, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street-Yawkey 10A, Boston, MA, 02114, USA
| | - Charles L Bormann
- Massachusetts General Hospital Fertility Center, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology, and Reproductive Biology, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street-Yawkey 10A, Boston, MA, 02114, USA
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Corkidi G, Hernández-Herrera P, Montoya F, Gadêlha H, Darszon A. Long-term segmentation-free assessment of head-flagellum movement and intracellular calcium in swimming human sperm. J Cell Sci 2021; 134:jcs.250654. [PMID: 33431515 DOI: 10.1242/jcs.250654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/14/2020] [Indexed: 12/31/2022] Open
Abstract
Human spermatozoa are the archetype of long-term self-organizing transport in nature and are critical for reproductive success. They utilize coordinated head and flagellar movements to swim long distances within the female reproductive tract in order to find and fertilize the egg. However, to date, long-term analysis of the sperm head-flagellar movements, or indeed those of other flagellated microorganisms, remains elusive due to limitations in microscopy and flagellar-tracking techniques. Here, we present a novel methodology based on local orientation and isotropy of bio-images to obtain long-term kinematic and physiological parameters of individual free-swimming spermatozoa without requiring image segmentation (thresholding). This computer-assisted segmentation-free method evaluates, for the first time, characteristics of the head movement and flagellar beating for up to 9.2 min. We demonstrate its powerful use by showing how releasing Ca2+ from internal stores significantly alters long-term sperm behavior. The method allows for straightforward generalization to other bio-imaging applications, such as studies of bull sperm and Trypanosoma, or indeed of other flagellated microorganisms - appealing to communities other than those investigating sperm biology.
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Affiliation(s)
- Gabriel Corkidi
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingenería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, 62210 Cuernavaca, México
| | - Paul Hernández-Herrera
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingenería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, 62210 Cuernavaca, México
| | - Fernando Montoya
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingenería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, 62210 Cuernavaca, México
| | - Hermes Gadêlha
- Department of Engineering Mathematics & Bristol Robotics Laboratory, University of Bristol, Bristol BS8 1QU, UK
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM, 62210 Cuernavaca, México
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Carichino L, Olson SD. Emergent three-dimensional sperm motility: coupling calcium dynamics and preferred curvature in a Kirchhoff rod model. MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA 2020; 36:439-469. [PMID: 30325451 DOI: 10.1093/imammb/dqy015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 09/11/2018] [Accepted: 09/17/2018] [Indexed: 11/15/2022]
Abstract
Changes in calcium concentration along the sperm flagellum regulate sperm motility and hyperactivation, characterized by an increased flagellar bend amplitude and beat asymmetry, enabling the sperm to reach and penetrate the ovum (egg). The signalling pathways by which calcium increases within the flagellum are well established. However, the exact mechanisms of how calcium regulates flagellar bending are still under investigation. We extend our previous model of planar flagellar bending by developing a fluid-structure interaction model that couples the 3D motion of the flagellum in a viscous Newtonian fluid with the evolving calcium concentration. The flagellum is modelled as a Kirchhoff rod: an elastic rod with preferred curvature and twist. The calcium dynamics are represented as a 1D reaction-diffusion model on a moving domain, the flagellum. The two models are coupled assuming that the preferred curvature and twist of the sperm flagellum depend on the local calcium concentration. To investigate the effect of calcium on sperm motility, we compare model results of flagellar bend amplitude and swimming speed for three cases: planar, helical (spiral with equal amplitude in both directions), and quasi-planar (spiral with small amplitude in one direction). We observe that for the same parameters, the planar swimmer is faster and a turning motion is more clearly observed when calcium coupling is accounted for in the model. In the case of flagellar bending coupled to the calcium concentration, we observe emergent trajectories that can be characterized as a hypotrochoid for both quasi-planar and helical bending.
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Affiliation(s)
- Lucia Carichino
- Department of Mathematical Sciences, Worcester Polytechnic Institute, 100 Institute Rd, Worcester, MA, USA
| | - Sarah D Olson
- Department of Mathematical Sciences, Worcester Polytechnic Institute, 100 Institute Rd, Worcester, MA, USA
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10
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Gallagher MT, Cupples G, Ooi EH, Kirkman-Brown JC, Smith DJ. Rapid sperm capture: high-throughput flagellar waveform analysis. Hum Reprod 2020; 34:1173-1185. [PMID: 31170729 PMCID: PMC6613345 DOI: 10.1093/humrep/dez056] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/01/2019] [Indexed: 11/12/2022] Open
Abstract
STUDY QUESTION Can flagellar analyses be scaled up to provide automated tracking of motile sperm, and does knowledge of the flagellar waveform provide new insight not provided by routine head tracking? SUMMARY ANSWER High-throughput flagellar waveform tracking and analysis enable measurement of experimentally intractable quantities such as energy dissipation, disturbance of the surrounding medium and viscous stresses, which are not possible by tracking the sperm head alone. WHAT IS KNOWN ALREADY The clinical gold standard for sperm motility analysis comprises a manual analysis by a trained professional, with existing automated sperm diagnostics [computer-aided sperm analysis (CASA)] relying on tracking the sperm head and extrapolating measures. It is not currently possible with either of these approaches to track the sperm flagellar waveform for large numbers of cells in order to unlock the potential wealth of information enclosed within. STUDY DESIGN, SIZE, DURATION The software tool in this manuscript has been developed to enable high-throughput, repeatable, accurate and verifiable analysis of the sperm flagellar beat. PARTICIPANTS/MATERIALS, SETTING, METHODS Using the software tool [Flagellar Analysis and Sperm Tracking (FAST)] described in this manuscript, we have analysed 176 experimental microscopy videos and have tracked the head and flagellum of 205 progressive cells in diluted semen (DSM), 119 progressive cells in a high-viscosity medium (HVM) and 42 stuck cells in a low-viscosity medium. Unscreened donors were recruited at Birmingham Women's and Children's NHS Foundation Trust after giving informed consent. MAIN RESULTS AND THE ROLE OF CHANCE We describe fully automated tracking and analysis of flagellar movement for large cell numbers. The analysis is demonstrated on freely motile cells in low- and high-viscosity fluids and validated on published data of tethered cells undergoing pharmacological hyperactivation. Direct analysis of the flagellar beat reveals that the CASA measure 'beat cross frequency' does not measure beat frequency; attempting to fit a straight line between the two measures gives ${\mathrm{R}}^2$ values of 0.042 and 0.00054 for cells in DSM and HVM, respectively. A new measurement, track centroid speed, is validated as an accurate differentiator of progressive motility. Coupled with fluid mechanics codes, waveform data enable extraction of experimentally intractable quantities such as energy dissipation, disturbance of the surrounding medium and viscous stresses. We provide a powerful and accessible research tool, enabling connection of the mechanical activity of the sperm to its motility and effect on its environment. LARGE SCALE DATA The FAST software package and all documentation can be downloaded from www.flagellarCapture.com. LIMITATIONS, REASONS FOR CAUTION The FAST software package has only been tested for use with negative phase contrast microscopy. Other imaging modalities, with bright cells on a dark background, have not been tested but may work. FAST is not designed to analyse raw semen; it is specifically for precise analysis of flagellar kinematics, as that is the promising area for computer use. Flagellar capture will always require that cells are at a dilution where their paths do not frequently cross. WIDER IMPLICATIONS OF THE FINDINGS Combining tracked flagella with mathematical modelling has the potential to reveal new mechanistic insight. By providing the capability as a free-to-use software package, we hope that this ability to accurately quantify the flagellar waveform in large populations of motile cells will enable an abundant array of diagnostic, toxicological and therapeutic possibilities, as well as creating new opportunities for assessing and treating male subfertility. STUDY FUNDING/COMPETING INTEREST(S) M.T.G., G.C., J.C.K-B. and D.J.S. gratefully acknowledge funding from the Engineering and Physical Sciences Research Council, Healthcare Technologies Challenge Award (Rapid Sperm Capture EP/N021096/1). J.C.K-B. is funded by a National Institute of Health Research (NIHR) and Health Education England, Senior Clinical Lectureship Grant: The role of the human sperm in healthy live birth (NIHRDH-HCS SCL-2014-05-001). This article presents independent research funded in part by the NIHR and Health Education England. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. The data for experimental set (2) were funded through a Wellcome Trust-University of Birmingham Value in People Fellowship Bridging Award (E.H.O.).The authors declare no competing interests.
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Affiliation(s)
- M T Gallagher
- School of Mathematics.,Institute for Metabolism and Systems Research, University of Birmingham, Birmingham, UK.,Centre for Human Reproductive Science, Birmingham Women's and Children's National Health Service Foundation Trust, Birmingham, UK
| | - G Cupples
- School of Mathematics.,Institute for Metabolism and Systems Research, University of Birmingham, Birmingham, UK.,Centre for Human Reproductive Science, Birmingham Women's and Children's National Health Service Foundation Trust, Birmingham, UK
| | - E H Ooi
- School of Engineering, Monash University Malaysia, Bandar Sunway, Malaysia
| | - J C Kirkman-Brown
- Institute for Metabolism and Systems Research, University of Birmingham, Birmingham, UK.,Centre for Human Reproductive Science, Birmingham Women's and Children's National Health Service Foundation Trust, Birmingham, UK
| | - D J Smith
- School of Mathematics.,Institute for Metabolism and Systems Research, University of Birmingham, Birmingham, UK.,Centre for Human Reproductive Science, Birmingham Women's and Children's National Health Service Foundation Trust, Birmingham, UK
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Gadêlha H, Hernández-Herrera P, Montoya F, Darszon A, Corkidi G. Human sperm uses asymmetric and anisotropic flagellar controls to regulate swimming symmetry and cell steering. SCIENCE ADVANCES 2020; 6:eaba5168. [PMID: 32789171 PMCID: PMC7399739 DOI: 10.1126/sciadv.aba5168] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/18/2020] [Indexed: 05/21/2023]
Abstract
Flagellar beating drives sperm through the female reproductive tract and is vital for reproduction. Flagellar waves are generated by thousands of asymmetric molecular components; yet, paradoxically, forward swimming arises via symmetric side-to-side flagellar movement. This led to the preponderance of symmetric flagellar control hypotheses. However, molecular asymmetries must still dictate the flagellum and be manifested in the beat. Here, we reconcile molecular and microscopic observations, reconnecting structure to function, by showing that human sperm uses asymmetric and anisotropic controls to swim. High-speed three-dimensional (3D) microscopy revealed two coactive transversal controls: An asymmetric traveling wave creates a one-sided stroke, and a pulsating standing wave rotates the sperm to move equally on all sides. Symmetry is thus achieved through asymmetry, creating the optical illusion of bilateral symmetry in 2D microscopy. This shows that the sperm flagellum is asymmetrically controlled and anisotropically regularized by fast-signal transduction. This enables the sperm to swim forward.
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Affiliation(s)
- Hermes Gadêlha
- Department of Engineering Mathematics, University of Bristol, BS8 1UB Bristol, UK
| | - Paul Hernández-Herrera
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Fernando Montoya
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Gabriel Corkidi
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingeniería Celular y Biocatálisis, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Oseguera-López I, Ruiz-Díaz S, Ramos-Ibeas P, Pérez-Cerezales S. Novel Techniques of Sperm Selection for Improving IVF and ICSI Outcomes. Front Cell Dev Biol 2019; 7:298. [PMID: 31850340 PMCID: PMC6896825 DOI: 10.3389/fcell.2019.00298] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 11/07/2019] [Indexed: 12/12/2022] Open
Abstract
Almost 50% of the infertility cases are due to male factors. Assisted reproductive technologies (ARTs) allow to overcome the incapacity of these patients' spermatozoa to fertilize the oocyte and produce a viable and healthy offspring, but the efficiency of the different techniques has still the potential to improve. According to the latest reports of the European Society of Human Reproduction and Embryology (ESHRE) and the Centers for Disease Control and Prevention of the United States (CDC), the percentages of deliveries per ART cycle in 2014 and 2016 were 21 and 22%, respectively. Among the reasons for this relatively low efficiency, the quality of the spermatozoa has been pointed out as critical, and the presence of high percentages of DNA-damaged spermatozoa in patients' ejaculates is possibly one of the main factors reducing the ARTs outcomes. Thus, one of the main challenges in reproductive medicine is to ensure the highest quality of the spermatozoa used in ARTs, and specifically, in terms of genetic integrity. The latest techniques for the preparation and selection of human spermatozoa are herein discussed focusing on those proven to improve one or several of the following parameters: sperm genetic integrity, fertilization capacity, embryo production, and in vitro survival, as well as pregnancy and delivery rates following in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). In addition, we discuss the potential of techniques developed in non-human mammals that could be further transferred to the clinic.
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Affiliation(s)
| | - Sara Ruiz-Díaz
- Mistral Fertility Clinics S.L., Clínica Tambre, Madrid, Spain
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Priscila Ramos-Ibeas
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
| | - Serafín Pérez-Cerezales
- Department of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain
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Corkidi G, Montoya F, Hernández-Herrera P, Ríos-Herrera WA, Müller MF, Treviño CL, Darszon A. Are there intracellular Ca2+ oscillations correlated with flagellar beating in human sperm? A three vs. two-dimensional analysis. Mol Hum Reprod 2018; 23:583-593. [PMID: 28911211 DOI: 10.1093/molehr/gax039] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/26/2017] [Indexed: 11/15/2022] Open
Abstract
STUDY QUESTION Are there intracellular Ca2+ ([Ca2+]i) oscillations correlated with flagellar beating in human sperm? SUMMARY ANSWER The results reveal statistically significant [Ca2+]i oscillations that are correlated with the human sperm flagellar beating frequency, when measured in three-dimensions (3D). WHAT IS KNOWN ALREADY Fast [Ca2+]i oscillations that are correlated to the beating flagellar frequency of cells swimming in a restricted volume have been detected in hamster sperm. To date, such findings have not been confirmed in any other mammalian sperm species. An important question that has remained regarding these observations is whether the fast [Ca2+]i oscillations are real or might they be due to remaining defocusing effects of the Z component arising from the 3D beating of the flagella. STUDY DESIGN, SIZE, DURATION Healthy donors whose semen samples fulfill the WHO criteria between the age of 18-28 were selected. Cells from at least six different donors were utilized for analysis. Approximately the same number of experimental and control cells were analyzed. PARTICIPANTS/MATERIALS, SETTING, METHODS Motile cells were obtained by the swim-up technique and were loaded with Fluo-4 (Ca2+ sensitive dye) or with Calcein (Ca2+ insensitive dye). Ni2+ was used as a non-specific plasma membrane Ca2+ channel blocker. Fluorescence data and flagella position were acquired in 3D. Each cell was recorded for up to 5.6 s within a depth of 16 microns with a high speed camera (coupled to an image intensifier) acquiring at a rate of 3000 frames per second, while an oscillating objective vibrated at 90 Hz via a piezoelectric device. From these samples, eight experimental and nine control sperm cells were analyzed in both 2D and 3D. MAIN RESULTS AND THE ROLE OF CHANCE We have implemented a new system that allows [Ca2+]i measurements of the human sperm flagellum beating in 3D. These measurements reveal statistically significant [Ca2+]i oscillations that correlate with the flagellar beating frequency. These oscillations may arise from intracellular sources and/or Ca2+ transporters, as they were insensitive to external Ni2+, a non-specific plasma membrane Ca2+ channel blocker. LARGE SCALE DATA N/A. LIMITATIONS REASONS FOR CAUTION Analysis in 3D needs a very fast image acquisition rate to correctly sample a volume containing swimming sperm. This condition requires a very short exposure time per image making it necessary to use an image intensifier which also increases noise. The lengthy analysis time required to obtain reliable results limited the number of cells that could be analyzed. WIDER IMPLICATIONS OF THE FINDINGS The possibility of recording flagellar [Ca2+]i oscillations described here may open a new avenue to better understand ciliary and flagellar beating that are fundamental for mucociliary clearance, oocyte transport, fertilization, cerebrospinal fluid pressure regulation and developmental left-right symmetry breaking in the embryonic node. STUDY FUNDING AND COMPETING INTEREST(S) This work was supported by Consejo Nacional de Ciencia y Tecnología (CONACyT) (grants 253952 to G.C.; 156667 to F.M.M. and Fronteras 71 39908-Q to A.D. and Post-doctoral scholarships 366844 to P.H.-H. and 291028 to F.M.) and the Dirección General de Asuntos del Personal Académico of the Universidad Nacional Autónoma de México (DGAPA-UNAM) (grants CJIC/CTIC/4898/2016 to F.M. and IN205516 to A.D.). There are no conflicts of interest to declare.
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Affiliation(s)
- G Corkidi
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, 62250, Mor., Mexico
| | - F Montoya
- Laboratorio de Imágenes y Visión por Computadora, Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, 62250, Mor., Mexico
| | - P Hernández-Herrera
- Centro de Investigación en Ciencias, Universidad Autónoma del Estado de Morelos, Cuernavaca, 62209, Mor., Mexico
| | - W A Ríos-Herrera
- Centro de Investigación en Ciencias, Universidad Autónoma del Estado de Morelos, Cuernavaca, 62209, Mor., Mexico
| | - M F Müller
- Centro de Investigación en Ciencias, Universidad Autónoma del Estado de Morelos, Cuernavaca, 62209, Mor., Mexico
| | - C L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM. Cuernavaca 62250, Mor., Mexico
| | - A Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, UNAM. Cuernavaca 62250, Mor., Mexico
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Gallagher MT, Smith DJ, Kirkman-Brown JC. CASA: tracking the past and plotting the future. Reprod Fertil Dev 2018; 30:867-874. [DOI: 10.1071/rd17420] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 04/06/2018] [Indexed: 12/19/2022] Open
Abstract
The human semen sample carries a wealth of information of varying degrees of accessibility ranging from the traditional visual measures of count and motility to those that need a more computational approach, such as tracking the flagellar waveform. Although computer-aided sperm analysis (CASA) options are becoming more widespread, the gold standard for clinical semen analysis requires trained laboratory staff. In this review we characterise the key attitudes towards the use of CASA and set out areas in which CASA should, and should not, be used and improved. We provide an overview of the current CASA landscape, discussing clinical uses as well as potential areas for the clinical translation of existing research technologies. Finally, we discuss where we see potential for the future of CASA, and how the integration of mathematical modelling and new technologies, such as automated flagellar tracking, may open new doors in clinical semen analysis.
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Cooper JC, Phadnis N. Parallel Evolution of Sperm Hyper-Activation Ca2+ Channels. Genome Biol Evol 2017; 9:1938-1949. [PMID: 28810709 PMCID: PMC5553355 DOI: 10.1093/gbe/evx131] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2017] [Indexed: 01/06/2023] Open
Abstract
Sperm hyper-activation is a dramatic change in sperm behavior where mature sperm burst into a final sprint in the race to the egg. The mechanism of sperm hyper-activation in many metazoans, including humans, consists of a jolt of Ca2+ into the sperm flagellum via CatSper ion channels. Surprisingly, all nine CatSper genes have been independently lost in several animal lineages. In Drosophila, sperm hyper-activation is performed through the cooption of the polycystic kidney disease 2 (pkd2) Ca2+ channel. The parallels between CatSpers in primates and pkd2 in Drosophila provide a unique opportunity to examine the molecular evolution of the sperm hyper-activation machinery in two independent, nonhomologous calcium channels separated by > 500 million years of divergence. Here, we use a comprehensive phylogenomic approach to investigate the selective pressures on these sperm hyper-activation channels. First, we find that the entire CatSper complex evolves rapidly under recurrent positive selection in primates. Second, we find that pkd2 has parallel patterns of adaptive evolution in Drosophila. Third, we show that this adaptive evolution of pkd2 is driven by its role in sperm hyper-activation. These patterns of selection suggest that the evolution of the sperm hyper-activation machinery is driven by sexual conflict with antagonistic ligands that modulate channel activity. Together, our results add sperm hyper-activation channels to the class of fast evolving reproductive proteins and provide insights into the mechanisms used by the sexes to manipulate sperm behavior.
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Ramírez-Reveco A, Villarroel-Espíndola F, Rodríguez-Gil JE, Concha II. Neuronal signaling repertoire in the mammalian sperm functionality. Biol Reprod 2017; 96:505-524. [PMID: 28339693 DOI: 10.1095/biolreprod.116.144154] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 01/24/2017] [Indexed: 12/14/2022] Open
Abstract
The common embryonic origin has been a recurrent explanation to understand the presence of "neural receptors" in sperm. However, this designation has conditioned a bias marked by the classical neurotransmission model, dismissing the possibility that neurotransmitters can play specific roles in the sperm function by themselves. For instance, the launching of acrosome reaction, a fundamental sperm function, includes several steps that recall the process of presynaptic secretion. Unlike of postsynaptic neuron, whose activation is mediated by molecular interaction between neurotransmitter and postsynaptic receptors, the oocyte activation is not mediated by receptors, but by cytosolic translocation of sperm phospholipase (PLCζ). Thus, the sperm has a cellular design to access and activate the oocyte and restore the ploidy of the species by an "allogenic pronuclear fusion." At subcellular level, the events controlling sperm function, particularly the capacitation process, are activated by chemical signals that trigger ion fluxes, sterol oxidation, synthesis of cyclic adenosine monophosphate, protein kinase A activation, tyrosine phosphorylations and calcium signaling, which correspond to second messengers similar to those associated with exocytosis and growth cone guidance in neurons. Classically, the sperm function associated with neural signals has been analyzed as a unidimensional approach (single ligand-receptor effect). However, the in vivo sperm are exposed to multidimensional signaling context, for example, the GABAergic, monoaminergic, purinergic, cholinergic, and melatoninergic, to name a few. The aim of this review is to present an overview of sperm functionality associated with "neuronal signaling" and possible cellular and molecular mechanisms involved in their regulation.
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Affiliation(s)
- Alfredo Ramírez-Reveco
- Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Franz Villarroel-Espíndola
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Department of Pathology and Pediatric Pathology, Yale University, New Haven, Connecticut, USA
| | - Joan E Rodríguez-Gil
- Unitat de Reproducció Animal, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Ilona I Concha
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
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Ishimoto K, Gaffney EA. Mechanical tuning of mammalian sperm behaviour by hyperactivation, rheology and substrate adhesion: a numerical exploration. J R Soc Interface 2017; 13:rsif.2016.0633. [PMID: 27852807 PMCID: PMC5134015 DOI: 10.1098/rsif.2016.0633] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/25/2016] [Indexed: 12/14/2022] Open
Abstract
The great mammalian sperm race encounters numerous microenvironments to which sperm must adapt and a fundamental sperm response is the change in its waveform owing to both fluid rheology and capacitation, with the latter associated with a hyperactivated beat pattern. Hence, in this modelling study, we examine the effect of different flagellar waveforms for sperm behaviour near adhesive substrates, which are representative of epithelia in female tract sperm reservoirs and the zona pellucida (ZP), which surrounds the mammalian egg. On contact with an adhesive surface, virtual sperm rotate to become nearly tangential with the surface, as generally observed. Hyperactivation also induces many effects: sperm exert greater forces on the substrate and periodically tug way from adhesions under circumstances reflecting binding at sperm reservoirs, but with extensive fluid elasticity, as found in the cumulus surrounding the ZP, sperm instead continually push into the substrate. Furthermore, with weak adhesion, rheological media increase the duration hyperactivated sperm remain in the proximity of a substrate. More generally, such results predict that changes owing to both hyperactivation of the flagellar waveform and the rheology of the surrounding medium provide a means of tuning sperm behaviour near, or attached to, adhesive substrates.
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Affiliation(s)
- Kenta Ishimoto
- The Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8501, Japan .,Research Institute for Mathematical Sciences, Kyoto University, Kyoto 606-8502, Japan
| | - Eamonn A Gaffney
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK
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Ishimoto K, Gadêlha H, Gaffney EA, Smith DJ, Kirkman-Brown J. Coarse-Graining the Fluid Flow around a Human Sperm. PHYSICAL REVIEW LETTERS 2017; 118:124501. [PMID: 28388208 DOI: 10.1103/physrevlett.118.124501] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Indexed: 06/07/2023]
Abstract
The flagellar beat is extracted from human sperm digital imaging microscopy and used to determine the flow around the cell and its trajectory, via boundary element simulation. Comparison of the predicted cell trajectory with observation demonstrates that simulation can predict fine-scale sperm dynamics at the qualitative level. The flow field is also observed to reduce to a time-dependent summation of regularized Stokes flow singularities, approximated at leading order by a blinking force triplet. Such regularized singularity decompositions may be used to upscale cell level detail into population models of human sperm motility.
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Affiliation(s)
- Kenta Ishimoto
- The Hakubi Center for Advanced Research, Kyoto University, Kyoto 606-8501, Japan
- Research Institute for Mathematical Sciences, Kyoto University, Kyoto 606-8502, Japan
| | - Hermes Gadêlha
- Department of Mathematics, University of York, York YO10 5DD, United Kingdom
- Institute for Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
- Centre for Human Reproductive Science, Birmingham Women's NHS Foundation Trust, Birmingham B15 2TG, United Kingdom
| | - Eamonn A Gaffney
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - David J Smith
- School of Mathematics, University of Birmingham, Birmingham B15 2TT, United Kingdom
- Institute for Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
- Centre for Human Reproductive Science, Birmingham Women's NHS Foundation Trust, Birmingham B15 2TG, United Kingdom
| | - Jackson Kirkman-Brown
- Institute for Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
- Centre for Human Reproductive Science, Birmingham Women's NHS Foundation Trust, Birmingham B15 2TG, United Kingdom
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Seminal CD38 Enhances Human Sperm Capacitation through Its Interaction with CD31. PLoS One 2015; 10:e0139110. [PMID: 26407101 PMCID: PMC4583300 DOI: 10.1371/journal.pone.0139110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/09/2015] [Indexed: 11/19/2022] Open
Abstract
Human sperm have to undergo a maturational process called capacitation in the female reproductive tract. Capacitation confers upon the sperm an ability to gain hypermotility and undergo acrosome reaction. Previous studies have suggested that seminal plasma proteins induce the capacitation of sperm in the female reproductive tract for the successful fertilization of the oocyte. However, the function of seminal plasma proteins in capacitation remains largely unclear. To the end, we found that soluble CD38 (sCD38) in seminal plasma increases the capacitation of sperm via specific interactions between sCD38 and the CD31 on the sperm. Upon the association of sCD38 with CD31, tyrosine kinase Src phosphorylates CD31, a process blocked by Src inhibitors. Shc, SHP-2, Grb2, and SOS, as well as Src kinase were found to associate with the phosphorylated CD31. The sCD38-induced phosphorylation of CD31 initiates a cascade reaction through the phosphorylation of Erk1/2, which results in the acrosome reaction, and sperm hypermotility. These processes were prevented by Src, Ras and MEK inhibitors. Taken together, these data indicate that the sCD38 present in seminal plasma plays a critical role in the capacitation of sperm.
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