Genome-wide copy number variation detection in a large cohort of diverse horse breeds by whole-genome sequencing.
Authors: Tang Xiangwei, Zhu Bo, Ren Ruimin, Chen Bin, Li Sheng, Gu Jingjing
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Genome-wide copy number variation detection in a large cohort of diverse horse breeds by whole-genome sequencing Tang et al., *Frontiers in Veterinary Science*, 2023 Copy number variations (CNVs)—segments of DNA present in differing quantities across individual genomes—represent a significant source of genetic diversity in horses, yet large-scale population studies using contemporary sequencing methods have remained limited. Tang and colleagues sequenced 97 horses spanning 16 breeds (including Thoroughbreds, Yakutian horses, Przewalski's horses, and various draft, sport, local and primitive breeds) using Illumina HiSeq technology to characterise breed-specific and common CNV regions (CNVRs) across the genome. The researchers identified between 5,053 and 44,681 CNVRs per breed with median segment lengths of 1.9–8 kb; population differentiation analysis of CNVRs in three genetically diverse populations revealed candidate genes (CTSL, RAB11FIP3, CTIF) potentially under selection pressure and involved in adaptation. These findings establish a substantial reference dataset for equine genetic research and highlight CNVRs as tractable targets for understanding breed-specific phenotypes and disease susceptibility, though the authors emphasise that identified associations require functional validation before application to breeding programmes or clinical decision-making.
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Practical Takeaways
- •Breeders can use this CNV dataset to identify genetic markers for breeding selection and to understand breed-specific genetic architecture, though findings require further validation
- •Understanding population-differentiated genes may help explain breed-specific traits and adaptability, informing breeding decisions for specific purposes (sport, draft, local conditions)
- •This genomic resource enables future studies linking CNVs to observable phenotypes and disease susceptibility in horses, potentially improving health and performance outcomes
Key Findings
- •Whole-genome sequencing of 97 horses from 16 breeds identified 5,053 to 44,681 breed-specific CNV regions per breed with median lengths of 1.9–8 kb
- •Population differentiation analysis across Thoroughbred, Yakutian, and Przewalski's horses identified candidate genes (CTSL, RAB11FIP3, CTIF) associated with selection and adaptation
- •This represents the largest breed and individual cohort in a whole-genome sequencing-based equine CNV study, including racing, sport, local, primitive, draft, and pony breeds