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. 2018 Jan;30(1):144-149.
doi: 10.1177/1040638717723946. Epub 2017 Sep 14.

A decade of using small-to-medium throughput allele discrimination assay to determine prion protein gene ( Prnp) genotypes in sheep in Slovenia

Jelka Zabavnik  1   2   3 , Marko Cotman  1   2   3 , Polona Juntes  1   2   3 , Ivan Ambrozic  1   2   3
Affiliations

A decade of using small-to-medium throughput allele discrimination assay to determine prion protein gene ( Prnp) genotypes in sheep in Slovenia

Jelka Zabavnik et al. J Vet Diagn Invest. 2018 Jan.

Abstract

Sheep with valine (V) at codon 136 and glutamine (Q) at codon 171 of the prion protein gene ( Prnp) are highly susceptible to classical scrapie, whereas phenylalanine (F) at codon 141 and histidine (H) at codon 154 play a major role in the susceptibility to atypical scrapie. A TaqMan real-time PCR assay was developed to determine Prnp alleles at codons 136, 141, 154, and 171 and used in classical scrapie eradication and breeding programs adopted in Slovenia. The frequency of the most resistant genotypes ARR/ARR and ARR/ARQ increased significantly in tested animals ( n = 35,138) from 6.7 and 27.1% of the tested sheep in 2006 to 12.1 and 32.4%, respectively, in 2015. Frequencies of more susceptible genotypes ARQ/ARQ and ARQ/VRQ decreased significantly from 36.4 and 3.5% in 2006 to 31.1 and 1.8%, respectively, in 2015. The most susceptible genotype VRQ/VRQ was detected in <0.5% of tested sheep. Frequencies of alleles AFRQ and AHQ affecting the susceptibility to atypical scrapie did not change significantly. The developed assay was suitable for genotyping on a small-to-medium throughput scale and was successfully used in classical scrapie eradication, as well as for the selection of classical scrapie-resistant sheep within breeding programs in Slovenia.

Keywords: Prion protein; real-time PCR; scrapie; sheep.

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Conflict of interest statement

Declaration of conflicting interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Numbers of sheep with Prnp genotypes determined each year (2006–2015; n = 35,138).
Figure 2.
Figure 2.
The annealing of primers and labeled probes for codons 136, 141, 154, and 171 on sequences of the Prnp gene (segment of the Ovis aries breed Texel chromosome 13, NCBI reference sequence: NC_019470.2). Positions of primer sequences are in boxes; positions of probes are written in italics and marked in gray. Bold letters indicate positions of polymorphisms in the region of the Prnp gene. Underlined small bold letters are those that are detected in PCRs.
Figure 3.
Figure 3.
A. Obtained frequencies of separate Prnp alleles in sheep per year. B. Percentages of genotypes per year obtained from genotyping blood samples from live sheep and muscle samples obtained from randomly sampled dead sheep.
See this image and copyright information in PMC

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References

    1. Belt PB, et al. Identification of five allelic variants of the sheep PrP gene and their association with natural scrapie. J Gen Virol 1995;76:509–517. - PubMed
    1. Bolton DC, et al. Identification of a protein that purifies with the scrapie prion. Science 1982;218:1309–1311. - PubMed
    1. de Andrade CP, et al. Development of a real-time polymerase chain reaction assay for single nucleotide polymorphism genotyping codons 136, 154, and 171 of the prnp gene and application to Brazilian sheep herds. J Vet Diagn Invest 2013;25:120–124. - PubMed
    1. European Commission. Commission Decision (2002/1003/EC) of 18 December 2002 laying down minimum requirements for a survey of prion protein genotypes of sheep breeds. Off J Eur Commun 2001;L349:105–107.
    1. European Commission. Regulation (999/2001/EC) of 22 May 2001 laying down rules for the prevention, control and eradication of certain transmissible spongiform encephalopathies. Off J Eur Commun 2001;L147:1–40.

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