Stallion sperm transcriptome comprises functionally coherent coding and regulatory RNAs as revealed by microarray analysis and RNA-seq.
Authors: Das Pranab J, McCarthy Fiona, Vishnoi Monika, Paria Nandina, Gresham Cathy, Li Gang, Kachroo Priyanka, Sudderth A Kendrick, Teague Sheila, Love Charles C, Varner Dickson D, Chowdhary Bhanu P, Raudsepp Terje
Journal: PloS one
Summary
# Editorial Summary Mature stallion sperm harbour a surprisingly complex and functionally organised collection of RNA molecules that extend far beyond remnants from testicular development, according to this landmark 2013 characterisation of the equine sperm transcriptome. Using microarray analysis of over 21,000 genes and RNA-seq generating 70 million raw reads, researchers identified 6,761 transcripts within sperm, including 165 sperm-enriched variants and 82 microRNAs, with sequence mapping revealing 4,504 known genes alongside 13,354 previously uncharacterised sequences distributed across all chromosomes. The identified transcripts clustered functionally around processes directly relevant to fertilisation—chemoattractant-activated signalling, ion transport, and membrane-vesicle dynamics—whilst additional messenger and micro RNAs appear positioned to influence early embryonic development. For equine practitioners, these findings suggest that sperm RNA profiles represent a selectively curated molecular fingerprint rather than random contamination, opening genuine possibilities for developing sperm-based fertility biomarkers to predict stallion breeding potential and diagnose subfertility at a molecular level. This foundational dataset provides the genomic scaffold necessary for future investigations into how sperm RNA dysfunction might underpin reproductive failure in individual stallions.
Read the full abstract on PubMed
Practical Takeaways
- •Sperm RNA profiles may serve as biomarkers for stallion fertility assessment and selection in breeding programmes
- •Understanding the functional complexity of sperm transcriptomes could improve diagnostic approaches to subfertility
- •The selective nature of sperm RNA content suggests potential targets for identifying breeding soundness in individual stallions
Key Findings
- •Stallion sperm contain 6,761 transcripts with 165 sperm-enriched and 155 differentially expressed between sperm and testes
- •RNA-seq identified 4,504 known horse/human genes and 82 miRNAs with coordinated functions in fertilization and early development
- •Sperm transcriptome shows functional coherence with enrichment for chemoattractant signal transduction and ion transport processes
- •Gene expression patterns suggest selective retention of functionally relevant RNAs rather than random spermatogenesis remnants