Genome-wide SNP assay in the Nero Siciliano pig to discover potential wild boar introgression

Genetic characterization is a fundamental prerequisite for managing animal genetic resources. Nowadays high-throughput commercial SNP platforms allow the genetic characterization of intra and inter-breeds diversity. The Illumina porcine SNP60 genotyping BeadChip was recently used for the genetic analysis of the autochthonous Nero Siciliano black pig, reared in the natural park of the Nebrodi Mountains. The comparison of 92 individuals well distributed in 22 farms with cosmopolitan breeds suggested the uniqueness of this breed. Moreover 100 randomly chosen SNP seemed enough to distinguish the investigated breeds, offering a useful tool for the traceability of typical products. Since cytogenetic investigation suggested a possible cross with wild boar in at least one Nero Siciliano pig, showing a rob(15;17), we compared the 92 individuals with 88 wild boars from a recent study on Northwest European breeds. The genetic structure of this dataset (180 individuals) was investigated by a Bayesian clustering approach with the ADMIXTURE software, which highlighted a low level of admixture between the wild boar and the domestic pig in almost all samples (81 out of 92 pigs). This admixture could be derived both from SNP recently introgressed or from common ancestors. In particular two Nero Siciliano pigs showed a higher proportion of admixture. Analyses are in progress to assess the origin of the introgression in these two subjects.