Specific microRNAs in stallion spermatozoa are potential biomarkers of high functionality

Area of Science:

• Reproductive Biology
• Molecular Biology
• Genomics

Background:

• Male subfertility affects various species, necessitating advanced diagnostic tools.
• Spermatozoal microRNAs (miRNAs) offer insights into sperm development and function.
• Density gradient centrifugation is used clinically to isolate high-quality sperm for artificial insemination.

Purpose of the Study:

• To discover and quantify miRNAs in stallion spermatozoa.
• To identify differentially expressed miRNAs between dense and less dense sperm populations.
• To explore the potential role of these miRNAs in sperm maturation and function.

Main Methods:

• Spermatozoa from seven stallions were separated into dense and less dense fractions using density gradient centrifugation.
• Small RNA sequencing was performed on 14 RNA samples (dense and less dense fractions).
• Bioinformatic analysis was used to identify and quantify mature miRNAs and precursors.

Main Results:

• 287 mature miRNAs were identified in stallion spermatozoa.
• Less dense spermatozoa exhibited fewer mature miRNAs and more precursor miRNAs compared to dense spermatozoa.
• Nine miRNAs were significantly more abundant in dense spermatozoa, with some predicted to target mRNAs involved in mRNA and protein decay.

Conclusions:

• Stallion spermatozoa contain a distinct miRNA profile.
• Differential miRNA expression suggests a role in regulating post-spermiogenesis processes.
• Specific miRNAs abundant in dense spermatozoa may serve as potential biomarkers for enhanced functional capabilities and fertility.