MHC variability supports dog domestication from a large number of wolves: high diversity in Asia

Abstract

The process of dog domestication is still somewhat unresolved. Earlier studies indicate that domestic dogs from all over the world have a common origin in Asia. So far, major histocompatibility complex (MHC) diversity has not been studied in detail in Asian dogs, although high levels of genetic diversity are expected at the domestication locality. We sequenced the second exon of the canine MHC gene DLA-DRB1 from 128 Asian dogs and compared our data with a previously published large data set of MHC alleles, mostly from European dogs. Our results show that Asian dogs have a higher MHC diversity than European dogs. We also estimated that there is only a small probability that new alleles have arisen by mutation since domestication. Based on the assumption that all of the currently known 102 DLA-DRB1 alleles come from the founding wolf population, we simulated the number of founding wolf individuals. Our simulations indicate an effective population size of at least 500 founding wolves, suggesting that the founding wolf population was large or that backcrossing has taken place.

Diversified Anchoring Features the Peptide Presentation of DLA-88*50801: First Structural Insight into Domestic Dog MHC Class I

“…Interestingly, the longer peptide K11 contains an incomplete a helix in the middle of the peptide ( Fig. 2E) in which intra-main chain hydrogen bonds are formed between the main chain atoms of Asp 4 and Gly 7 , as well as between Lys 5 and Phe 8 , which contribute to the peptide conformation (Fig. 2F).…”

“…MHC sequence variation across dog breeds and within indigenous dog populations has been found to be high, which suggests that domestic dogs have a diverse origin based on a large founding gray wolf population and have subsequently been involved in significant backcrossing (4)(5)(6). East Asian dogs have a higher MHC diversity than do dogs from other locations, indicating that modern domestic dogs may have a common origin in East Asia (4), although recent genome-wide single nucleotide polymorphism and haplotype analyses suggest gray wolves from the Middle East as a dominant source for dog breeds (3). Despite the importance of dogs in studying domestic animal evolution and human immune diseases, molecular characterization of the DLAs has lagged behind that of mouse and human MHC molecules, as well as those from other agricultural animals.…”

Disease: A Hitherto Unexplored Constraint on the Spread of Dogs (Canis lupus familiaris) in Pre-Columbian South America

“…One quite comprehensive genetic study suggests a single origin some 15,000 years ago, followed by further admixture with wolves during the ensuing domestication process (Freedman et al 2014), but rejects the specifically East Asian centre of domestication proposed previously on the basis of mitochondrial DNA (mtDNA) and Y chromosome data (Ding et al 2012;Pang et al 2009;Savolainen et al 2002). A broadly Asian source is, however, indicated by another study that compared variability in selected components of the nuclear DNA of European and Asian dogs (Niskanen et al 2013), while a third investigation, which focused on autosomal as well as mtDNA and Y chromosome diversity, points to Central Asia (Shannon et al 2015). Ancient mtDNA recovered from a 33,000-year-old canid from southern Siberia's Altai Mountains that aligns it with dogs, rather than wolves, also highlights this general area, but at a much earlier period (Druzhkova et al 2013).…”

Did disease constrain the spread of domestic dogs (Canis familiaris) into Sub-Saharan Africa?

“…One of the most recent and comprehensive genetic analyses points to a single origin some 15,000 years ago, followed by further admixture with wolves during the ensuing domestication process (Freedman et al 2014). A broadly Asian source is also indicated by a recent study comparing variability in selected components of the nuclear DNA of European and Asian dogs (Niskanen et al 2013). Neither study supports earlier claims for an East Asian centre of dog domestication that were based purely on mitochondrial DNA evidence (Savolainen et al 2002;Pang et al 2009), although recently published analysis of ancient mitochondrial DNA from a 33,000-year-old canid from the Altai Mountains of southern Siberia, which aligns it with dogs, rather than wolves, suggests yet another potential area of origin .…”