Genetic variability of the bracco italiano dog breed based on microsatellite polimorphism

The Bracco Italiano is one of the oldest pointing dog breed, used for hunting ever since the Renaissance time. Today it has increasing importance as to be the winner of the “Eukanuba World Challenge 2009”, one of the most prestigious events of dog shows in USA. In this work we illustrate an assessment of the genetic variability for 21 STRs typed in a sample of 72 unrelated Italian hounds (“Bracchi” - BI) and a sample of 43 dogs from other 23 different breeds (“Other dogs” - OD). The aim of the present study was to estimate the genetic variability of the BI dog breed using microsatellite markers, in order to provide information useful in conservation purposes. Three multiplexes were worked out, which allowed analyzing 21 STR markers from the panels recommended for the 2006 and 2008 ISAG canine comparison test. Allele size in bp was determined using the comparison-test reference samples as anchor values. Number of alleles, allele frequencies, deviations from Hardy-Weinberg proportions, linkage disequilibrium among loci, genetic similarity, genetic distances and molecular coancestry-based parameters were calculated. The number of different alleles ranged 3 to 9 (mean 6.43) in the BI, compared with 6-11 (mean 8.52) in the OD, whereas the expected heterozygosity ranged 0.44- 0.81 (mean 0.64) compared with 0.51-0.89 (mean 0.81). In BI the genetic similarity within the whole population was high (0.455±0.018); this parameter reveals the great homogeneity of the sampled animals as confirmed also by the small kinship distance (0.336) and by the high values of the self molecular coancestry (0.703) and of the inbreeding coeffi cient (0.406).