Abstract
Genetic differentiation of Awassi sheep of Jordan and Merino sheep from Australia was investigated using six microsatellite markers (MS). Three studied populations of each Awassi and Merino revealed high genetic variation. Awassi middle population was most genetically variable which might be a result of gene flow. However, lower genetic variation was observed in Merino populations which might due to breeding practices under which selection took place. Overall results indicated an evolutionary distinction of Awassi sheep from Merino sheep. Furthermore, the individual admixture assigned them to predefined population resulted in successful genetic differentiation of Awassi sheep from Merino sheep.
On the other hand, the average admixture proportion of Awassi and Merino individuals was low (20%) indicating non-admixed individuals in general. This result is probably due to common ancestry origin and recent migration. The assignment analysis was grouping individuals in clusters belonging to each separated population rather than being mixed population. Finally, genetic distances and phylogenetic tree evolutionary separated Awassi from Merino flocks. These results are in agreement with known history of the populations in regards to their far away geographical location and their long evolutionary distinct. To sum up, evidences of recent crossbreeding were not observed between Awassi and Merino sheep in Jordan.