Genetic diversity of Syrian Arabian horses.

The study examines the genetic diversity in Syrian Arabian horses, specifically testing the theory that the three main strains (Saglawi, Kahlawi, and Hamdani) stem from three original founders as indicated in studbooks. Despite an existing system of strain classification, these genetic findings do not align, signifying a need to revamp existing breeding practices. More importantly, the high genetic diversity found within these Syrian strains shows the potential of Syrian Arabian horses as a crucial genetic repository.

Methodology

• 48 Syrian Arabian horses from the Saglawi, Kahlawi, and Hamdani strains participated in the study, along with 24 Arabian horses from the USA and three Przewalski’s horses as an outgroup for comparison.
• Each horse was examined using the Equine SNP70K BeadChip, a high-density genotyping technology that assesses single nucleotide polymorphisms (minor genetic variations).

Key Findings

• The observed heterozygosity ranged between 0.30 and 0.32, expected heterozygosity between 0.30 and 0.31, and inbreeding coefficients between -0.02 and -0.05, indicating a high degree of genetic diversity within Syrian strains.
• The genetic differentiation among the Syrian strains was palpably low, refuting the notion that the strains are genetically distinct.
• Hierarchical clustering generated three clusters of horses with varied geographical and strain affiliations, suggesting the multi-faceted genetic makeup of these horses.

Implications

• The findings contradict the proposed studbook lineage, causing researchers to question the validity of the current strain classification system.
• Despite substantiating the theory of three founding horses, the genetic disparities among the strains necessitate reconsideration of existing breeding practices.
• The high genetic diversity in Syrian Arabian horses positions them as an important genetic resource, potentially contributing to the conservation and health of the horse species.