Since domestic dogs of seemingly unrelated breeds often form large groups based on identical control region sequences in mitochondrial genome DNA analysis, this study attempted to break up these large haplotype groups by analyzing the remaining approximately 15,484 pairs of the canine mitochondrial genome for 79 dogs and use phylogenic and population genetic methods in searching for additional variability in the form of single nucleotide polymorphisms (SNPs).
Collectively, the results show that although there is more variability in the mitochondrial control region (mtCR), the percentage of unique SNPs is relatively constant throughout the genome. Incorporation of SNPs outside of the mtCR increases the number of informative SNPs for forensic use to 57 percent of the total SNPs found. Collectively, the 79 dogs in the dataset formed 10 groups and 47 unique haplotypes with 8 ambiguous sequences. Knowing that the domestic dog mitochondrial control region (mtCR) does not have the discriminatory power of the human mtCR, and also knowing that there are approximately 15,458 additional base pairs (bps) of mitochondrial genome (mtGenome) outside of the control region, this study sequenced the remainder of the genomes for 64 domestic dogs from the mtCR study. Researchers combined sequences with 15 complete mtGenome sequences downloaded from Genbank and used phylogenetic and population genetic methods in order to analyze the 79 genomes and report these relationships and the variable sites in the remainder of the genome that will aid in further discriminating between dogs with common mtCR sequences. Since dogs and humans occupy many of the same environments, dog hair is often found in criminal investigations either when a dog is directly involved in a crime or as secondary transfer from either the victim or suspect. Being able to trace dog hairs to a particular breed can provide useful information in an investigation. 6 tables, 3 figures, and 28 references
Date Published: March 1, 2009