This study evaluated a 60 bp sequence variation hotspot in the canine mitochondrial DNA hypervariable region 1 for use in forensic investigations.
The study concluded that targeting the 60 bp hotspot region of the mtDNA canine genome could be an effective, robust, and rapid method for excluding individuals from a population as the source of a questioned sample. In cases where there may be many samples to analyze, the analytical time can be significantly reduced if the 60 bp hotspot screening technique is used as a first step in the analytical process. In addition, targeting this 60 bp hotspot will result in a higher success of amplification of degraded evidence samples than targeting larger fragments. If this region excludes an individual dog as a contributor of the questioned sample, then no further testing would be needed. The study also shows that the inclusion of more globally representative mtDNA sequences does not significantly increase the exclusion capacity estimates. Each local sample was found to be equally highly variable and undifferentiated from others, and the sample size was sufficiently large to be representative of the broader geographic sample. Blood samples were obtained from veterinary diagnostic laboratories in California, Colorado, Massachusetts, Ohio, and Texas. Hair root samples were collected from volunteers’ dogs in California. These samples represented 30 distinct breeds recognized by the American Kennel Club. In addition to DNA extraction, the descriptions of materials and methods address PCR amplification, DNA degradation, species specificity, DNA sequencing, and data analysis. 7 tables, 1 figure, and 15 references