Assessment of the population structure and genetic diversity of Denizli chicken subpopulations using SSR markers

The aim of this study was to characterise the genetic diversity, genetic relationship and population structure within local Turkish Denizli chicken subpopulations in rural areas using 19 microsatellite markers. To assess the uniqueness and relations of the Denizli subpopulations we used six local Italian chicken breeds’ samples, which were genotyped in the same laboratory with the same molecular markers. In total, 105 alleles were found across 19 microsatellite loci with a mean number of 5.53 alleles per locus. Considering all subpopulations and loci, genetic differentiation based on global FST was 0.030 (p <.01). Global FIS values (0.200) indicated that non-random mating occurred in all subpopulations of Denizli fowl and all subpopulations deviated significantly (p <.01) from HWE. Over all subpopulations, the mean observed heterozygosity was 0.473, ranging from 0.399 to 0.562. Genetic differentiations between pairs of subpopulations based on the proportion of shared alleles ranged 0.140–0.297. The neighbour-net tree, based on marker estimated kinship distances, separated Denizli subpopulations and Italian breeds into two main clusters. The most likely number of different populations was estimated using the clustering procedure implemented in STRUCTURE. Structure analysis showed a clear separation of the Denizli fowl subpopulations from the Italian populations. A second step sub-clustering allowed discriminating among the six subpopulations of Denizli breed. The results of this study can be used as baseline genetic information to place breeders’ flocks in conservation programmes, controlling inbreeding and safeguarding the genetic variability of the populations.