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In Vitro Sperm-Epididymosomes Interaction Immediately Before Fertilization Changes Sperm Fertility Potential
Maíra Bianchi Rodrigues Alves1, Maria Alice de Almeida2, Ana Beatriz Bossois Moura2
1Department of Pathology, Theriogenology and One Healthy, School of Agricultural and Veterinary Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil.
Andrology
|May 30, 2026
Summary
Cauda epididymosomes (epEVs) in bulls enhance sperm fertility. Incubation with epEVs improved in vitro fertilization, leading to higher blastocyst rates, suggesting epEVs positively modulate male fertility potential.
Area of Science:
- Reproductive Biology
- Extracellular Vesicles
- Sperm Biology
Background:
- Sperm gain fertility during epididymal maturation and are stored in the cauda epididymis.
- Cauda epididymosomes (epEVs) may influence sperm fertility, but their role is not well understood.
Purpose of the Study:
- To investigate the impact of cauda epididymosomes (epEVs) on sperm fertility potential in cattle.
- To establish an optimal protocol for sperm-epEV interaction.
Main Methods:
- Characterized bovine cauda epEVs for size, concentration, morphology, and markers.
- Determined optimal epEVs/sperm ratio (1000:1) and incubation time (3 hours) for sperm-epEV interaction using flow cytometry.
- Analyzed microRNA transfer from epEVs to sperm via qPCR.
- Assessed the effect of sperm-epEV interaction on in vitro fertilization and subsequent blastocyst rates.
Main Results:
- Bovine cauda epEVs were characterized with specific size, concentration, morphology, and markers (ALIX, CD-81, CD-63).
- The optimal interaction protocol involved 1000 epEVs/sperm for 3 hours, leading to the detection of specific microRNAs (miR-935, miR-421) in sperm.
- Sperm incubated with epEVs showed significantly higher blastocyst rates (38.9%) compared to controls (26.6%).
Conclusions:
- In vitro incubation of sperm with cauda epididymosomes (epEVs) enhances male fertility potential.
- EpEVs modulate the paternal contribution to embryo development, offering insights into controlling male fertility.
- This study establishes a foundation for utilizing epEVs to improve assisted reproductive technologies.
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