Polymorphism Analyses of 19 STRs in Labrador Retriever Population from China and Its Heterozygosity Comparisons with Other Retriever Breeds

Pure breed dogs of Western origin are increasingly more popular in China as is a need to differentiate breeds and individual dogs for personal and forensic reasons. Research on genetic diversities of the canine population in China is rarely conducted. In this study, genetic distributions and forensic efficiencies of 19 canine STR loci in Labrador Retriever population from China were evaluated by using one available commercial canine kit in China. This panel was used to genetically define 214 Labrador Retrievers in China, as an example of one of the most important Western breeds and to compare them with Labrador Retrievers from America based on three overlapping STR loci. Moreover, genetic relationship analyses between Labrador Retriever population and two reference populations in America were performed. All 19 STR loci were polymorphic and conformed to Hardy-Weinberg equilibrium in the studied population. The STR panel was able to discern individual dogs with a high degree of accuracy. Breed-wide genetic heterozygosity comparisons based on present and published allele frequencies revealed that the studied population had the lower genetic heterozygosity than canine populations in America. Principal component analysis among Labrador Retriever population and other reference populations showed that the studied Labrador Retrievers were genetically close to the retriever breeds in America. Population genetic structure analyses among these canine breeds further revealed genetic differentiations between the studied Labrador Retriever population and other compared breeds. In conclusion, these STR loci had relatively high forensic values in Labrador Retriever population in China, which could be employed for individual identification and kinship testing.