Mitochondrial DNA Sequence Variation in Portuguese Native Dog Breeds: Diversity and Phylogenetic Affinities

Abstract

In an extensive survey of the genetic diversity in Portuguese dogs, we have examined an 887-bp fragment of the mitochondrial DNA (mtDNA) from 8 Portuguese, 1 Spanish, and 2 North African native dog breeds, including village dogs from Portugal and Tunisia. Forty-nine haplotypes were found in the 164 individuals analyzed, with private haplotypes being found in several breeds. For example, the Castro Laboreiro Watchdog, a rare breed from a small and isolated region in Portugal, was monomorphic for mtDNA and possessed a new haplotype, which may be provisionally considered a breed-specific marker. Phylogenetic analyses recapitulated 4 major clades identified in other studies, but new haplotypes, grouping within a clade that was previously thought as geographically restricted, were detected in Portugal and Morocco. Portuguese village dogs showed no genetic differentiation from nonnative dogs or from local breeds of the areas in which the village dogs were sampled. Although Iberian and North African dog breeds possessed breed-specific mtDNA haplotypes, no significant geographic structure could be detected among them. There is no evidence for introgression of North African haplotypes in Iberian dogs, contrary to previous results for other domestic animals.

Complex population structure in African village dogs and its implications for inferring dog domestication history

“…S6), the clades that are believed to contain Ͼ95% of domestic dogs (6). Over the region sequenced in (6) and ignoring indels, we found 18 African haplotypes that were not described by (6); 14 in A clade [one of which was found in Africa by (10)], one in B clade, and three in C clade. The Puerto Rican and United States mixed-breed dogs had 8 A clade and one B clade haplotypes (only one haplotype, a Puerto Rican A clade haplotype, ws not previously described in ref.…”

“…Their results confirmed previous mtDNA evidence of dog domestication from Eurasian wolves (5), showed that East Asian dogs had the highest mtDNA diversity of any region, suggesting an East Asian origin of domestication. However, subsequent work by Pires et al (10) has shown that mtDNA does not show significant population structure in village dogs. Because Savolainen et al included many East Asian village dogs but few village dogs from other regions, their conclusion of high levels of East Asian diversity is likely a consequence of high levels of mitochondrial diversity in village dogs and not necessarily an indication of East Asian domestication.…”

Roman dogs from the Iberian Peninsula and the Maghreb – A glimpse into their morphology and genetics

“…The mtDNA sequence of the African dog specimen belongs to clade A, which is nowadays the most common lineage found in dogs worldwide, including North Africa (Boyko et al, 2009) and Iberia (Pires et al, 2006). Here we contribute only one sample from Thamusida: interestingly, it shared a clade A haplotype with three other samples from Lugo.…”

“…The identification of dog clades was undertaken through comparison with reference sequence data of extant Iberian dogs and wolves trimmed to the 181 base pairs fragment. Detry and Cardoso, 2010) reference sequence data on extant dogs from Iberia and North Africa, and comprising breed and village dogs from 1) Pires et al (2006), 49 haplotypes, 887 base pair long with GenBank accession numbers AY706476eAY706524 (Pires et al, 2006); and 2) Pang et al (2009), haplotypes A4, A5, A10, A11, A19, A20, A22, A33, A34, A127, B1, D6, D7 (Pang et al, 2009). An alignment of all these sequences/haplotypes is available from Partial_MtDNA_SequenceAlignment_DOG__Roman_QInt (fasta).…”

“…Clades A, B, C and D represent the majority of the maternal diversity found in dogs. Clade A is the most frequent lineage currently observed in dogs from Europe (including Iberia) and North Africa, whereas clade D is the less represented and geographically restricted to Portugal, Spain, Morocco, Turkey and Scandinavia in present times (Ardalan et al, 2011;Pires et al, 2006;Savolainen et al, 2002). Extant dogs from Iberia and North Africa have high genetic diversity, carrying haplotypes belonging to clades A, B, C and D (Pires et al, 2006).…”