Detecting rare introgression of domestic dog genes into wild wolf ( Canis lupus ) populations by Bayesian admixture analyses of microsatellite variation

摘要: Hybridization with free-ranging dogs isthought to threat the genetic integrity ofwolves in Europe, although available mtDNA dataevidenced only sporadic cases of crossbreeding.Here we report results population assignmentand admixture analyses 107wild-living Italian wolves, 95 including30 different breeds and feral dogs, andcaptive-reared wolves unknown or hybridorigins, which were genotyped at 18microsatellites. Two showedunusually dark coats (``black wolves''), oneshowed a spur both hindlegs (``fifth fingerwolf''), suggesting hybridization. Italianwolves showed significant deficit ofheterozygotes, positive FIS values anddeviations from Hardy-Weinberg equilibrium.Genetic variability was significantlypartitioned between groups, thatwolves represent distinct gene pools.Multivariate ordination individual genotypesand clustering inter-individual geneticdistances split into twodifferent clusters congruent priorphenotypic classification, but hybrids andwolves origin not identifiedfrom information alone. By contrast, aBayesian analysis assigned all theItalian two differentclusters, independent any prior phenotypicinformation, simultaneously detected theadmixed composition hybrids, whichwere more than one cluster.Captive-reared wereprevalently wolfpopulation. Admixture that one``black wolf'' had mixed ancestry dog genepool could be hybrid, while other twowolves unusual phenotypes tothe wolf population.