Genetic differentiation between Segugio dell’Appennino and Segugio Maremmano dog breeds assessed by microsatellite markers

Abstract

The domestic dog (Canis Familiaris) was the first species to be tamed and bred to occupy a variety of functions. The Segugio dell’Appennino and Segugio Maremmano are two Italian breeds used extensively as hunting dogs. Microsatellites and other genetic markers are useful tools in evaluating the within and between breed genetic variation. The aim of this study was to investigate genetic differentiation among the two breeds through the analysis of 21 microsatellite markers. The two populations share the same geographical regions but have been over time selected on different parameters to achieve specific functions. All the analysed microsatellite markers were polymorphic and the average number of alleles per locus was 8.19. The mean FIT index (0.051; P<0.05) highlights that at some point in time, the normal gene flow among the animals was disrupted, giving rise to a heterozygote deficiency in both breeds, and this is confirmed by the mean FST fixation index (0.010; P<0.05) clearly indicating an absence of a significant genetic differentiation between the two breeds. The mean FIS value was significantly different from zero (0.042) (P<0.05) reconfirming the presence of a lack of heterozygosity in the studied samples. The values of observed and expected heterozygosity were similar in the two breeds. AMOVA, PCA and STRUCTURE analysis, all emphasise the lack of significant differences among the two breeds in terms of genetic differentiation. The presence of a population substructure is probably due to a genetic introgression from different Segugio breeds, that can be confirmed with further studies.