Genetic Characterization of the Arabian Horse Population in Tunisia Using Microsatellites

The genetic diversity and population structure of Tunisian Arabian horses were assessed using highly polymorphic microsatellite markers, which are critical for conservation and breeding programs. Despite the cultural and economic importance of Arabian horses in Tunisia, molecular data supporting their management remain limited. In this study, DNA from 130 horses was genotyped with 17 ISAG-FAO-recommended microsatellites to evaluate diversity within Eastern and Western Arabian lineages and their relationship to Thoroughbreds. Eastern Arabians showed an average of 5.176 alleles per locus, observed heterozygosity of 0.657, expected heterozygosity of 0.677, and a fixation index of 0.028, while Western Arabians displayed 5.941 alleles, heterozygosity values of 0.689 (Ho) and 0.688 (He), and a fixation index of -0.006. Genetic differentiation was low between Eastern and Western Arabians (0.011) but moderate between Eastern Arabians and Thoroughbreds (0.071), with high gene flow within Arabian subpopulations (0.950). Principal component analysis confirmed distinct subpopulations. These findings highlight high genetic diversity in Western Arabians and variable heterozygosity in Eastern Arabians, providing a molecular basis for targeted breeding strategies to preserve genetic traits, control inbreeding, and ensure the long-term sustainability of Tunisian Arabian horse populations.