Estimating the probability of identity in a random dog population using 15 highly polymorphic canine STR markers

Dog DNA-profiling is becoming an important supplementary technology for the investigation of accident and crime, as dogs are intensely integrated in human social life. We investigated 15 highly polymorphic canine STR markers and two sex-related markers of 131 randomly selected dogs from the area around Innsbruck, Tyrol, Austria, which were co-amplified in three PCR multiplex reactions (ZUBECA6, FH2132, FH2087Ua, ZUBECA4, WILMSTF, PEZ15, PEZ6, FH2611, FH2087Ub, FH2054, PEZ12, PEZ2, FH2010, FH2079 and VWF.X). Linkage testing for our set of marker suggested no evidence for linkage between the loci. Heterozygosity (HET), polymorphism information content (PIC) and the probability of identity (P(ID)theoretical, P(ID)unbiased, P(ID)sib) were calculated for each marker. The HET(exp)-values of the 15 markers lie between 0.6 (VWF.X) and 0.9 (ZUBECA6), P(ID)sib-values were found to range between 0.49 (VWF.X) and 0.28 (ZUBECA6). Moreover, the P(ID)sib was computed for sets of loci by sequentially adding single loci to estimate the information content and the usefulness of the selected marker sets for the identification of dogs. The estimated P(ID)sib value of all 15 markers amounted to 8.5 × 10−8. The presented estimations turned out to be a helpful approach for a reasonable choice of markers for the individualisation of dogs.