Characterization of sperm cell membrane charge and selection of high-quality sperm using microfluidics in stallions.
Abstract: Intracytoplasmic sperm injection (ICSI) is the only method for in vitro embryo production (IVP) in horses. Besides oocyte developmental competence, the outcome of IVP is also highly dependent on sperm quality. Therefore, it is not only essential to employ superior methods of selecting high quality sperm, but also to be able to characterize which quantifiable properties of sperm quality are most indicative of its fertility. In men, a net negative surface charge, estimated by zeta potential (ZP) is highly correlated with sperm quality and in vitro embryo developmental outcomes. However, there is no information available about approximate charges or ZP in equine sperm. Therefore, in this study we aimed to characterize equine sperm ZP and identify its associations with known measures of sperm quality. Additionally, we aimed to complete a comprehensive comparison of conventional sperm selection techniques as compared to the novel method of microfluidic sorting. Ejaculates (n = 22) were partitioned into fresh (∼23 °C, 0 h; n = 12) and cooled (∼4 °C, 24 h; n = 10) groups, and processed by swim up (SU), density gradient centrifugation (DGC), density gradient-swim up combination (DG-SU), and microfluidic chip (MF) sorting. Motility, progressive motility, cell viability, normal morphology, and ZP were evaluated for both unprocessed fractions and post-selected fractions. The ZP of both fresh and cooled samples was net negative and also correlated with motility and progressive motility for both fresh and cooled samples (P < 0.05). The ZP of cooled samples was also correlated with viability (P < 0.05). Among the compared methods of sperm selection, MF was highly effective in selecting high quality sperm as determined by the measured parameters. Percent motility, progressive motility, normal morphology, and viability of MF selected sperm were of higher quality than sperm selected by SU, and of similar to DG-SU and DGC without the use of potentially harmful centrifugation steps. Correlations between ZP, motility, and viability parameters may indicate a role of external charge on the motility and survival of sperm within the female reproductive tract. In conclusion, we identified an average net negative ZP on equine sperm and correlations between ZP and other measures of sperm quality, as well as having identified MF as a novel effective method of equine sperm selection for IVP.
Copyright © 2022 Elsevier Inc. All rights reserved.
Publication Date: 2022-08-17 PubMed ID: 36007376DOI: 10.1016/j.theriogenology.2022.08.014Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research article focuses on characterizing the surface charge of stallion sperm cells and examines the use of microfluidics for selecting high-quality sperm. The study further investigates the significance of sperm cell surface charge in sperm quality and fertility.
Objective and Relevance of the Study
- All in vitro horse embryo production (IVP) is carried out using a procedure referred to as Intracytoplasmic sperm injection (ICSI).
- The success of IVP is highly dependent on the quality of sperm. Therefore, it is crucial to use advanced methods for selecting high-quality sperm.
- In men, sperm quality correlates with a net negative surface charge, as measured by zeta potential (ZP), but this is unexplored territory in equine sperm. The research, therefore, aims to identify and understand this link.
Approach and Methodology
- Twenty-two ejaculates, split into fresh (23°C, 0h; 12 samples) and cooled (4°C, 24h; 10 samples) categories, were processed through various popular sperm selection techniques and evaluated based on motility, progressive motility, cell viability and ZP, both before and after selection.
- The methods of sperm selection compared were: swim up (SU), density gradient centrifugation (DGC), density gradient and swim up combined (DG-SU), and microfluidic chip sorting (MF).
Findings
- Surface charges (ZP) of both fresh and cooled samples were found to be net negative, in line with findings in male human sperm.
- The experiment showed correlations between ZP, motility, and progressive motility for both fresh and cooled samples. For cooled samples, ZP complimented viability.
- Upon comparing sperm selection methods, microfluidics (MF) proved to be very efficient in selecting preferable sperm.
- The sperm selected through MF demonstrated better motility, progressive motility, morphology, and viability than sperm selected by SU, and was in line with DG-SU and DGC methods, without the need for potentially harmful centrifugation.
Conclusion
- The study uncovered a net negative ZP on equine sperm, establishing correlations between ZP and other measures of sperm quality.
- The microfluidic method was recognized as an effective new means of selecting quality equine sperm for IVP.
- The correlations between ZP, motility and viability could imply that an external charge plays a role in sperm survival and motility within the female reproductive tract.
Cite This Article
APA
Orsolini MF, Verstraete MH, van Heule M, Orellana D, Ortega A, Meyers S, Dini P.
(2022).
Characterization of sperm cell membrane charge and selection of high-quality sperm using microfluidics in stallions.
Theriogenology, 192, 1-8.
https://doi.org/10.1016/j.theriogenology.2022.08.014 Publication
Researcher Affiliations
- Department of Population Health and Reproduction, University of California, Davis, CA, USA.
- Department of Population Health and Reproduction, University of California, Davis, CA, USA; Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, University of Ghent, 133 Salisburylaan, 9820, Merelbeke, Belgium.
- Department of Population Health and Reproduction, University of California, Davis, CA, USA; Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, University of Ghent, 133 Salisburylaan, 9820, Merelbeke, Belgium.
- Department of Population Health and Reproduction, University of California, Davis, CA, USA.
- Department of Population Health and Reproduction, University of California, Davis, CA, USA.
- Anatomy, Physiology, and Cell Biology, 1089 Veterinary Medicine Dr, School of Veterinary Medicine, University of California, Davis, CA, USA.
- Department of Population Health and Reproduction, University of California, Davis, CA, USA. Electronic address: pdini@ucdavis.edu.
MeSH Terms
- Animals
- Cell Membrane
- Female
- Horses
- Humans
- Male
- Microfluidics
- Semen
- Sperm Motility
- Spermatozoa
Conflict of Interest Statement
Declaration of competing interest All of the authors have agreed to the submission of this manuscript and to be responsible for its contents and declare no conflicts of interest.
Citations
This article has been cited 1 times.- Yousefi M, Khalili MA, Eftekhar M, Woodward BJ, Anbari F, Mangoli E. Sperm Selection Using Cumulus Cell Column Improves Sperm DNA Integrity, Embryo Morphokinetics, and Clinical Outcomes Following ICSI: A Randomized Clinical Trial. Reprod Med Biol 2025 Jan-Dec;24(1):e70000.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
