The transcriptome of equine peripheral blood mononuclear cells.
Authors: Pacholewska Alicja, Drögemüller Michaela, Klukowska-Rötzler Jolanta, Lanz Simone, Hamza Eman, Dermitzakis Emmanouil T, Marti Eliane, Gerber Vincent, Leeb Tosso, Jagannathan Vidhya
Journal: PloS one
Summary
# Editorial Summary Comprehensive transcriptomic analysis of equine peripheral blood mononuclear cells from 85 Warmblood horses (561 samples analysed via RNA sequencing) has substantially improved the horse genome annotation, revealing that many predicted equine genes actually produce multiple transcript variants rather than the single isoforms currently documented. The researchers identified 7,531 previously unannotated transcripts, of which approximately 3,280 appear to be horse-specific and 230 show strong evidence of coding for functional proteins; nine of these novel coding transcripts were experimentally validated using RT-PCR and Sanger sequencing. This work addresses a critical gap in equine genomic resources—over half of predicted horse gene models remain unvalidated and lack experimental support—which has limited the accuracy of genetic studies and biomarker discovery in the species. For equine professionals, improved genome annotation enables more reliable interpretation of genetic tests, more accurate identification of disease-associated variants, and better-informed breeding decisions, whilst for researchers it provides a solid foundation for understanding gene expression in immune cells, which is particularly relevant to conditions involving immune dysregulation such as recurrent airway obstruction and equine asthma. The release of this experimental transcriptomic dataset therefore represents a significant advance in equine genomic knowledge with direct applications across veterinary practice, nutrition, and performance management.
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Practical Takeaways
- •This foundational genomic work improves understanding of equine gene expression patterns, supporting future research into disease susceptibility and performance traits in horses
- •The discovery of horse-specific transcripts highlights the limitations of extrapolating findings from model organisms and supports continued investment in equine-specific research
- •Better annotation of the equine genome enables more accurate interpretation of genetic data relevant to breeding decisions and health management
Key Findings
- •RNA-seq of 561 PBMC samples from 85 horses identified 7,531 novel transcripts not present in public equine gene databases
- •Of novel transcripts, 3,280 showed no homology to known sequences, suggesting horse-specific genes
- •230 novel transcripts demonstrated high coding potential with ≥2 exons and ≥300 nt open reading frames
- •9 new equine coding transcripts were experimentally validated using RT-PCR and Sanger sequencing