Mitochondrial DNA sequence heteroplasmy levels in domestic dog hair

To assess the level of mtDNA sequence heteroplasmy in dog hair, we sequenced a 612 base pair fragment of the hypervariable region 1 (HVI) in 576 hairs from six dogs representing a range of age, sex, breed, and hair color. Blood and buccal samples were collected from each dog for reference. Three instances of sequence heteroplasmy were observed at nucleotide positions 15627 (G/A), 15628 (T/C) and 15639 (G/A) in two hairs from different dogs. An HVI sequence heteroplasmy frequency of 0.0034 was obtained. The Probability of Identity (PI) value, or probability that two random, unrelated dog hairs share an HVI sequence, and the Power of Discrimination (PD), or probability that two random unrelated dog hairs have different HVI sequences, were determined from the 88 HVI haplotypes represented in the Veterinary Genetics Laboratory database (n = 1006) and found to be 0.086 and 0.914, respectively.