Genome-wide detection of copy number variations among diverse horse breeds by array CGH.
Authors: Wang Wei, Wang Shenyuan, Hou Chenglin, Xing Yanping, Cao Junwei, Wu Kaifeng, Liu Chunxia, Zhang Dong, Zhang Li, Zhang Yanru, Zhou Huanmin
Journal: PloS one
Summary
# Editorial Summary Copy number variations (CNVs)—segments of DNA present in different numbers of copies across individuals—represent a substantial source of genetic diversity in horses, yet their contribution to breed characteristics and environmental adaptation remained poorly characterised until this research. Wang and colleagues employed array comparative genomic hybridisation to systematically map CNVs across six horse breeds, including four Chinese plateau breeds (Mongolia, Abaga, Hequ, and Kazakh horses), plus Debao ponies and Thoroughbreds, identifying 700 individual CNVs spanning 353 distinct regions that collectively encompassed approximately 13.59 Mb (0.61%) of the equine genome and affected roughly 518 genes (2.26% of all horse genes). Notably, seven genes within CNV regions showed particular association with high-altitude adaptation in plateau breeds, suggesting that copy number variation plays a measurable role in the physiological resilience required for survival in severe environments. For equine professionals, these findings indicate that genetic variation extends beyond simple single nucleotide polymorphisms, and that breeding strategies, disease susceptibility assessments, and performance predictions in different breeds may need to account for this structural genomic variation, particularly when working with horses selected for challenging climates or specific environmental niches.
Read the full abstract on PubMed
Practical Takeaways
- •CNVs are a significant source of genetic variation in horses and may explain breed-specific traits and performance characteristics
- •Understanding CNV patterns in plateau breeds may inform selective breeding strategies for animals destined for high-altitude or environmentally challenging conditions
- •Genetic mapping of CNVs provides a foundation for future research linking specific genomic variations to observable phenotypes in different equine populations
Key Findings
- •700 CNVs identified across 6 horse breeds ranging from 6.1 Kb to 0.57 Mb, accounting for 0.61% of the horse genome
- •353 CNV regions affected 518 annotated genes, representing approximately 2.26% of all horse genes
- •7 genes with CNVs identified as potentially related to adaptation of plateau horses to severe high-altitude environments
- •First comprehensive map of copy number variations in Chinese horse breeds demonstrating CNVs are ubiquitous and influence multiple biological processes