Single Nucleotide Polymorphism in Interleukin-6 and Interleukin-8 Genes of Equines.
Authors: Kumar Sanjeev, Ashraf Mohammad, Pannu Urmila, Mehta Sharat Chandra
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: IL-6 and IL-8 Gene Polymorphisms in Equines Cytokine expression in equines responds dynamically to exercise, with interleukins IL-6 and IL-8 playing key roles as myokines produced during muscle activity. Kumar and colleagues sequenced IL-6 and IL-8 genes across 42 animals representing four horse breeds (Marwari, Kathiawari, Manipuri, Zanskari) and two donkey breeds (Poitou, Halari) to identify single nucleotide polymorphisms that might influence inflammatory and performance responses. The researchers identified four SNPs: an intronic C>T substitution in IL-6 (Poitou donkeys only), a functionally significant non-synonymous G>C change in IL-8 exon 1 causing a leucine-to-phenylalanine amino acid substitution at position 10 across all breeds studied, a T>C intron substitution in IL-8, and a 5′ UTR heterozygous C/G variant in Poitou donkeys. The non-synonymous IL-8 variant is particularly noteworthy, as amino acid position 10 lies within the signal peptide region critical for protein secretion; breed-specific differences in allele frequencies might influence inflammatory responses to training and stress, potentially affecting recovery capacity and injury predisposition. These genetic variants warrant investigation in larger populations to determine whether they correlate with performance phenotypes, inflammatory status post-exercise, or susceptibility to inflammatory conditions—knowledge that could inform breeding decisions and individualised training protocols.
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Practical Takeaways
- •IL-8 genetic variation exists across equine breeds and may influence inflammatory and myokine responses to exercise, relevant for training and performance optimization
- •The non-synonymous IL-8 SNP alters protein sequence (Leu10>Phe10) which could affect cytokine function and post-exercise muscle inflammation in individual horses
- •Genetic polymorphisms in inflammatory cytokine genes may explain variable recovery responses to exercise between individual equines and breeds
Key Findings
- •An intronic SNP (C>T) in IL-6 exon 2 was identified in Poitou donkeys at position EquCab3.0:4:54607583
- •A non-synonymous SNP (G>C) in IL-8 exon 1 causing leucine to phenylalanine substitution (p.Leu10>p.Phe10) was found in all 4 horse breeds and 2 donkey breeds at position EquCab3.0:3:63720817
- •A T>C substitution in IL-8 intron 1-2 was detected in all equids studied at position EquCab3.0:3:63720770
- •A heterozygous SNP (C/G) in the IL-8 5' UTR of Poitou donkeys was observed at position EquCab3.0:3:63720883