Since little nuclear DNA is present in shed dog hair, which is often found at crime scenes, a 1,000 base pair fragment of the mitochondrial control region (mtCR) from 552 dogs was assessed for forensically useful sequence variation.
The research shows that the domestic dog (mtCR) has not been thoroughly surveyed for sequence variation and that a single database composed of purebred and mixed-breed dogs is sufficient for the continental United States. Study results are consistent with analyses from earlier studies that showed domestic dogs can be classified into four previously identified genetic groups as defined by mtCR variation. Combining 427 newly sequenced domestic dog mtCRs with a previous study of 125 domestic dog mtCRs enabled the identification of both new haplotypes and new informative single nucleotide polymorphisms (SNPs). In the majority of the 552 dogs, 52.2 percent were classified into 1 of the 9 large haplotype groups, with between 11 and 59 individuals per group. The presence of such large groups underscores the need for DNA sequence analysis of the remainder of the domestic dog mitochondrial genomes in the hope of identifying additional discriminatory SNPs in order to increase the resolution of the analysis. When dogs are grouped by breed, the breeds have less genetic variation than the population as a whole. These population analyses demonstrate the need to sample across a variety of breeds, including multiple individuals of the same breed. 5 tables, 3 figures, and 28 references
Date Published: March 1, 2009