Genomic characterization of Italian and European pig populations

Thanks to the genomic revolution we can today take advantage of molecular and bioinformatic tools for dissecting phenotypic traits and genetic differences among modern commercial pig breeds, local populations and wild boars. This is important for European autochthonous and endangered pig breeds, whose genetic architecture remains uncharacterized and breeding potential unexploited. This project aimed to investigate genomic features of autochthonous pig breeds focusing on candidate gene markers associated to disease resistance, coat colour, vertebral number and genes involved in feeding preferences. First of all, we used a genotyping approach to define the distribution of disease resistance marker alleles in Italian local pig populations, confirming the robustness of local pig breeds. Results derived from the association study between investigated disease resistance markers and production traits, suggested that it could be possible to introduce disease resistance traits in pig breeding programs without affecting productivity. Regarding the relationship between local pig populations and wild boars, we performed an analysis monitoring the allelic distribution at two evolutionary important loci, involved in coat colour and vertebral number determination. Results suggested that Sus scrofa genome is experiencing bidirectional introgression of wild and domestic alleles, with autochthonous breeds undergoing a “de-domestication” process and wild resources challenged by a “domestication” drift. In the last part of this project we evaluated the genetic variability of taste receptor genes across European pig populations. We performed a SNP discovery study to find out similarities and differences in taste sensing system among local breeds. Taste perception is connected to the diet and the environment and comparing differences between pig breeds in these genes allows to reconstruct the history of breeds and the impact of ecology in their biodiversity. Our results can be considered a basis for the use of genetic variability among local pig populations and for further studies regarding their characterization