Genetic diversity in chicken populations based on microsatellite markers

The genomes of jungle and domestic fowl populations maintained in Ukraine and Germany were screened using microsatellites as molecular markers. Genetic variation within and between strains of different origin and performance potential was estimated and genetic distances between them were determined. To characterise and compare 26 populations studied, 253 individuals in all were genotyped for 14 microsatellite markers covering 11 linkage groups. Over all 14 microsatellite loci, the number of alleles ranged between 2 and 21 per locus, the total number of alleles being 157 (or 11.2 per locus). The allele size range observed was from 2 bp (in locus MCW0098) to 108 bp (in locus MCW0119) and averaged 32.9 bp. The portion of alleles shared among populations varied from 50% (in locus MCW0119) to 100% (in loci MCW0020, MCW0098, MCW0165) and averaged 8.5 per locus. The alleles shared among populations were often the most frequent alleles within each locus and population. The values for observed heterozygosity and gene diversity per locus ranged from 0.08 (MCW0154) to 0.62 (MCW0029) and from 0.39 (MCW0098) to 0.90 (MCW0005), respectively. The total average heterozygosity and gene diversity were 0.41 and 0.70, respectively. Using Nei's distance and the Neighbour-Joining method (software package PHYLIP version 3.5c, Felsenstein 1994), a phylogenetic tree was reconstructed, its topology reflecting general patterns of relatedness and genetic differentiation between the chicken populations studied. The red junglefowl (Gallus gallus) formed a separate branch and demonstrated a specific allele distribution when compared to domestic fowl breeds. The Poltava Clay chickens (subjected to intensive selection for egg production traits since 1950 and further crossbreeding with Rhode Island Reds) and two pure commercial layer lines from the Lohmann Tierzucht GmbH breeding company made up another separate branch. The native breeds were grouped within the third branch but showed a different degree of relatedness and crossbreeding. The strains of the Australorp Black chickens from Germany and Ukraine were genetically not similar, reflecting differences in their population histories.