Encephalopathy in sheep was at first described in Ireland in 1732 and was called scrapie. AncientDNA in archaeogenetics represents an effective method to evaluate the ancestral pedigree of livinganimals and track evolutionary changes occurred between the past and the present day. Sinceseveral point mutations are today widely described in modern scrapie, no data about both sequenceand frequency are still available for the prion protein (PrP) gene in ancient breeds. In orderto evaluate whether the haplotypes distribution in ancient sheep differed from those of themodern population we evaluated polymorphism at four well know codons of the Prp Open ReadingFrame. In the present work, we collected 37 medieval sheep bone remains found at the Calathamet(n = 11), Palazzo Bonagia (n = 12) and Palazzo Steri (n = 14) Sicilians archeological sitesand dated back between 9th - 15th century. Single nucleotide polymorphisms (SNPs) at codons 136,141, 154 and 171 of the prion protein (PrP) were investigated using cycle sequencing. SequenomMass ARRAYiPLEX platform confirmed the results for 5 individuals out of 37. Cycle sequencingshowed at all samples the AA136LL141RR154QQ171 (hereafter ALRQ/ALRQ) genotype except at 2 individuals showing the very susceptible genotype VLRQ/VLRQ (n = 1) and the resistant (ALRR/ALRR) (n = 1) respectively. Supported by a high incidence of susceptible genotype to prion infectionwe concluded that presumably scrapie was already widespread enough in the medieval Sicily.Moreover, we described conceivable scenarios that could have underlain evolutionary changes inthe medieval sheep population.
|Number of pages||9|
|Journal||OPEN JOURNAL OF ANIMAL SCIENCES|
|Publication status||Published - 2015|