Population structure and signature of selection for body size in some Iranian and exotic horse breeds.
Authors: Bazvand Banafsheh, Rashidi Amir, Zandi Mohammad Bagher, Moradi Mohammad Hossein, Rostamzadeh Jalal, Mahmoudi Peyman
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Genomic Selection Signatures in Iranian and Exotic Horse Breeds Understanding the genetic basis of body size and performance traits across different horse populations has practical implications for breeding decisions and genetic conservation. This research used genotyping data (50–70K SNPs) combined with discriminant analysis and selection signature testing (FLK and hapFLK tests) to examine six breeds: three Iranian natives (Caspian pony, Turkmen, Kurdish) and three exotic breeds (Fell pony, Arabian, Akhal-Teke). Population genetic analysis revealed clear clustering patterns, with ponies forming a distinct group from light horse breeds, whilst the Akhal-Teke and Turkmen breeds showed closer genetic relationships, suggesting shared ancestry and selection pressures. The researchers identified 124–127 candidate genes under selection, of which several have roles in bone development, osteoblast differentiation, and growth factor signalling; notably, seven genes (SAMD7, SPARC1, IBSP, MEPE, DEUP12, PLAAT1, SPP1) represent novel findings not previously associated with equine morphology. For breeding programmes and genetic management, these findings offer potential genomic markers linked to size-related traits, though practitioners should note that larger sample sizes and functional validation studies are needed before these candidates can be reliably incorporated into selection strategies or used to predict performance outcomes across different management systems.
Read the full abstract on PubMed
Practical Takeaways
- •Understanding genomic regions controlling body size can inform selective breeding programs for performance optimization in both Iranian native and exotic horse breeds.
- •The identification of novel candidate genes provides new molecular markers for evaluating genetic potential related to morphological traits and breed characteristics.
- •Results suggest that distinct populations have different genetic architectures for body size; breeding decisions should account for these population-specific genomic signatures.
Key Findings
- •DAPC analysis revealed clear separation between pony and light horse breeds, with Akhal-Teke and Turkmen clustering together and Fell ponies forming a distinct group.
- •FLK and hapFLK tests identified 124 and 127 candidate genes under selection, respectively, across the six studied breeds.
- •Seven novel genes (SAMD7, SPARC1, IBSP, MEPE, DEUP12, PLAAT1, and SPP1) linked to body size and bone development were identified and not previously reported in equine genomics studies.
- •Selection signatures were associated with genes involved in bone mineralization, osteoblast differentiation, growth factor signaling, and tissue development.