The Domestication Syndrome hypothesis in free-ranging dogs

Research context Domestic animals differ from their wild ancestors in a broad range of phenotypic traits and it has been suggested that such traits have a common developmental basis, rather than being the result of independent selection processes (Domestication Syndrome - DS). There is growing evidence that domestication may have affected gene regulatory networks that can modify the migration rate of neural crest cells (Neurocristopathy domestication hypothesis), affecting a range of developmental processes and highlighting a potential underlying mechanism of the DS. However, studies directly testing the predictions of the DS hypothesis have been rare, and results showing a decoupling of traits in domestic animals have questioned its validity. Furthermore, although the genetic link to neural crest cell migration has been demonstrated for some domestication-related traits, it remains unclear for others. Hypothesis & Predictions Here we test the DS hypothesis and its underlying neurocristopathy basis using free-ranging domestic dogs (FRDs) as a model. Together the two aspects of the DS hypothesis predict that behavioural and morphological traits typical for domesticated animals should be highly correlated (P1), have a common developmental basis resulting from alteration of gene regulatory networks affecting the neural crest cell migration (P2), and behavioural DS traits, but not morphological traits should be associated with direct fitness benefits (P3). Methods We test these predictions in a well-studied FRD population in Morocco using a combination of behavioural, genomic and ecological methods. Individual morphological traits will be based on photographs and behavioural traits will be assessed via systematic observations of conspecific social behaviour (and subsequent social network analyses) and experiments (e.g. assessment of neophobia and human-directed sociability). The genetic variation underlying behavioural traits will be studied using genome-wide SNP analysis and targeted sequencing and genetic reconstruction of kin structure will be used to assess the heritability of the DS traits. Measures of fitness will include reproductive success, the diversity of diet (based on stable isotope analysis), and survival and body mass index for pups. Originality This study will provide the first comprehensive test of the DS hypothesis, considering its behavioural, morphological and genetic aspects by applying a multi-disciplinary approach developed by the collaborating groups. The innovative use of FRD and the study design will allow testing the association between genetic variation and directly observed behaviours of dogs in a natural setting, where the potential fitness of these traits is likely to be highly relevant. Primary researchers The project will be based on collaboration of experts in canine behaviour (Sarah Marshall-Pescini and Friederike Range, Konrad Lorenz Institute, Austria) and genetics (Malgorzata Pilot, Polish Academy of Sciences).