Analysis of Animal Genetic Resources for the Identification of Polymorphisms Associated with Phenotypic Features and Evolutionary Aspects

Coat colour has been one of the main target of both natural and artificial selection and in particular one of the first of domestication process. This Thesis has been focused on the detection of genetic variability of new variants in coat colour genes in different species, especially those associated with particular coat colour phenotypes and introgression of domesticated alleles in wild populations. The aim of this Thesis was to identify and analyse polymorphisms associated with phenotypic traits that have been selected during the domestication processes and may differentiate breeds or populations in several livestock species, i.e. rabbit, donkey and pig, and evaluate the potential evolutionary effects on the wild counterparts, considering the specific example of the introgression between domestic pigs and wild boar populations. In particular, two main genes involved in melanin production (TYR and TYRP1) have been characterized in donkeys and rabbits respectively and variants in these genes have been significantly associated with albinism, suggesting that rabbits and donkeys could be considered as animal models for human albinism because these variants have never been detected in humans. Another aim of this Thesis, was the possibilty to use coat colour genes as introgression markers and the results suggest that accurate monitoring and management of rural stock populations, in order to avoid backcrossing events, are needed both for the conservation of the ecologic natural equilibrium of wild environments and to make wild species less invasive for human activities. Obtained results have been also evaluated for applications that consider allele and genotype frequency differences for authentication purposes, in order to differentiate meat products originating from wild boars, considered an upper market niche, against pig meat products with a less economic value.