NR ATEF
AU Slate,J.
TI Molecular evolution of the sheep prion protein gene
QU Proceedings of the Royal Society B: Biological Sciences 2005 Nov 22; 272(1579): 2371-7
PT journal article
AB Transmissible spongiform encephalopathies (TSEs) are infectious, fatal neurodegenerative diseases characterized by aggregates of modified forms of the prion protein (PrP) in the central nervous system. Well known examples include variant Creutzfeldt-Jakob Disease (vCJD) in humans, BSE in cattle, chronic wasting disease in deer and scrapie in sheep and goats. In humans, sheep and deer, disease susceptibility is determined by host genotype at the prion protein gene (PRNP). Here I examine the molecular evolution of PRNP in ruminants and show that variation in sheep appears to have been maintained by balancing selection, a profoundly different process from that seen in other ruminants. Scrapie eradication programs such as those recently implemented in the UK, USA and elsewhere are based on the assumption that PRNP is under positive selection in response to scrapie. If, as these data suggest, that assumption is wrong, eradication programs will disrupt this balancing selection, and may have a negative impact on the fitness or scrapie resistance of national flocks.
IN Aufgund einer statistischen Analyse von Sequenzdaten kommt der Autor zu der Vermutung, dass die verschiedenen Prionprotein-Genotypen beim Schaf im Gegensatz zu anderen Wiederkäuern bisher einer balancierenden Selektion unterlegen habe, die man vielleicht besser nicht durch den nationalen britischen Scrapie-Plan stören sollte.
MH Animals; *Evolution, Molecular; Gene Frequency; Great Britain; Mutation; Phylogeny; PrPc Proteins/*genetics; Ruminants/genetics; Selection (Genetics); Sheep/*genetics; United States; Variation (Genetics)
AD University of Sheffield, Department of Animal and Plant Sciences, Sheffield, S10 2TN, UK. j.slate@sheffield.ac.uk
SP englisch
PO England