Estimating population structure and genetic diversity of five Moroccan sheep breeds by microsatellite markers

â¿¢Genetic diversity of Moroccan sheep breeds was analysed using microsatellites for the first time.â¿¢The breeds showed a relatively high level of gene diversity.â¿¢The result reveals high levels of gene flow and genetic admixture occurred between breeds.

Investigating the genetic variability and structure of Moroccan sheep breeds will reveal crucial information for the conservation and management of this population. This study used 22 microsatellite markers to assess the genetic diversity among and within five Moroccan sheep breeds: Sardi (N = 35), Boujaad (N = 31), Timadhite (N = 35), Beni Guil (N = 35), and D⿿man_Morroco (N = 35). In the whole sample, a total of 299 alleles were detected. The five breeds showed a relatively high level of gene diversity ranging between 0.725 (D⿿man_Morocco) and 0.764 (Timahdite). The Analysis of Molecular Variance (AMOVA) indicated that variability among populations contributed only 3.64% of the observed genetic diversity. Wilcoxon tests of excess heterozygosity under the two-phase model (TPM) did not provide strong evidence for recent bottlenecks in the five studied breeds. Unrooted neighbour joining (NJ) tree for the modified Cavalli-Sforza chord distance (DA), pairwise multilocus estimates of an effective number of migrants (Nm) and the Bayesian clustering method cohesively revealed poor structure of genetic variation among breeds. Our results also show that in spite of the high level of phenotypic diversity in the Moroccan sheep breeds, the past breeding strategies could lead to genetic admixture occurring as a result of relatively high gene-flow among the breeds.