Genetic variation and gene flow among Tunisian sheep populations using Random Amplified Polymorphic DNA (RAPD) markers.

Random amplified polymorphic DNA (RAPD) was used to infer the magnitude and pattern of genetic differentiation among sheep populations belonging to two native Tunisian breeds (the Barbarine and the Western thin tail). Eight primers generated 62 scorable bands, of which 44 were polymorphic. Genetic differentiation between populations within breeds was detected based on the estimated FST index. The value of gene flow (Nm) was 5.5361 and 3.5763 in Barbarine and Western thin tail breeds respectively. The diversity within populations (Hs) recorded demonstrates important genetic variation within them. The values of genetic differentiation coefficient (Gst) over all loci were 0.0828 and 0.1227 respectively between populations of the Barbarine and Western thin tail breeds. The principal component analysis (PCA) did not show a clear differentiation between populations within breeds. The results show that studied sheep populations maintain a high genetic diversity in the range of 0.21-0.23 and their genetic differentiation is consistent with their geographic origin. It is therefore necessary to preserve the purity of the Tunisian local breeds that are well adapted to country’s bioclimatic conditions.