Using a proposed canine forensic kit, this study used 18 short tandem repeat (STR) loci selected specifically for identity testing of canines in order to examine STR diversity and genetic subdivision among dogs of pedigreed and mixed ancestry across various regions of the United States.
Regardless of breed, mixed breed, or geographic region, the gene diversity for the combined 18 loci is high; therefore, it can be anticipated that these loci will be useful for identity testing for most forensic and kinship analyses; however, because of the known selection and in-breeding history of the domestic dog, it is important to assess the impact of population substructure and how it may impact estimates of the rarity of a canine STR profile. Canine biological specimens are often part of the physical evidence from crime scenes. Prior to the current research, there has been no validated canine-specific reagent kit available. For the research reported in this paper, a multiplex genotyping system composed of 18 STRs and a sex-linked zinc finger locus for gender determination was developed for generating population genetic data in assessing the weight of canine forensic DNA profiles. The kit's panel of 18 STRs was shown to be informative and robust for the identity testing of canines. The database, which is constructed based on the 18 STRs, is more comprehensive than other dog STR databases in terms of regional representation of pedigreed and mixed-breed dog populations in the United States. The genetic profiles and allele frequencies of important dog breeds in the United States that are popular as house pets and/or dangerous as vicious animals are also represented in the database. The kit and the accompanying population genetic database should combine to provide a valuable resource that could develop into a universally accepted canine forensic STR system. 9 tables, 5 figures and 41 references