Differentiation of European wild boar (Sus scrofa scrofa) and domestic swine (Sus scrofa domestica) meats by PCR analysis targeting the mitochondrial D-loop and the nuclear melanocortin receptor 1 (MC1R) genes

This work describes the differentiation of European wild boar (Sus scrofa scrofa) and domestic swine (Sus scrofa domestica) meats by PCR targeting sequences from two molecular markers: the mitochondrial displacement loop (D-loop) region and the nuclear melanocortin receptor 1 (MC1R) gene. A polymorphic D-loop fragment (∼270 bp) was amplified and sequenced in a number of wild and domestic Sus scrofa meat samples, to find a nucleotide region suitable for PCR–RFLP analysis. Sequence data showed the presence of only a few point mutations across Sus scrofa D-loop sequences, not allowing direct discrimination between wild boar and domestic swine meats. Later, the MC1R gene was targeted and Sus scrofa-specific primers designed to amplify a 795 bp MC1R fragment. Subsequent RFLP analysis of the MC1R swine-specific amplicons allowed selection of BspHI and BstUI endonucleases to carry out intraspecific Sus scrofa differentiation. Digestion of MC1R amplicons with the chosen enzymes generated characteristic PCR–RFLP profiles that allowed discrimination among meats from wild and domestic swine specimens. The technique also enabled the detection of samples that yielded heterozygous profiles, suggesting hybrids resulting from wild boar and domestic pig breeding. The PCR–RFLP reported here, targeting the MC1R gene may be routinely applied to verify the correct labelling of game products.