Analysis of the PRNP gene polymorphisms in healthy Greek sheep during 2012 – 2016


Keywords:
classical scrapie resistance/susceptibility PrP genotypes breeding programme
E. BOUKOUVALA
E. KATHAROPOULOS
S. CHRISTOFORIDOU
M. BABETSA
L. V. EKATERINIADOU
Abstract

Scrapie is a slowly progressive infectious disease of sheep and goats that causes degeneration of the central nervous system. Scrapie is one of several transmissible spongiform encephalopathies (TSEs), like the bovine spongiform encephalopathy (BSE). In sheep, polymorphisms at codons 136, 154 and 171 of the host gene PRPN that encodes the PrP protein, are known to be closely linked to susceptibility or resistance to natural and experimental classical scrapie. In many countries, but not in Greece, breeding programs have been implemented to increase genetic resistance. This study was supported mainly by the private initiatives of farmers willing to improve their flocks by increasing the resistance to scrapie. Thus, the PrP genotypes (of the three mentioned codons) from 5815 blood samples of clinically healthy rams from 160 healthy flocks during the period 2012 – 2016 were determined. Additionally, 1399 blood samples were genotyped only for the 171 codon. Samples were analyzed by Real Time PCR (TaqMan probes) with specific labeled probes. Our results showed an increased percentage of the two genotypes, ARR/ARR and ARR/ARQ linked with resistance to the disease (27.29% and 34.6%, respectively) and relatively reduced percentage of the genotype ARQ/ARQ (24.23%) which is associated with susceptibility to disease and is the most common genotype in the Greek flocks. This joined effort has resulted in the establishment of an important number of farms with an increased population of genetically resistant rams to classical scrapie.

Article Details
  • Section
  • Research Articles
Downloads
Download data is not yet available.
References
Acin C, Martín-Burriel I, Goldmann W, Lyahyai J, Monzo M, Bolea R, Smith A, Rodellar C, Badiola JJ, Zaragoza P (2004) Prion protein gene polymorphisms in healthy and scrapie- affected Spanish sheep. J Gen Vir 85: 2103–2110.
Acutis PL, Sbaiz L, Verburg F, Riina MV, Ru G, Moda G, Caramelli M, Bossers A (2004) Low frequency of the scrapie resistance-associated allele and presence of lysine-171 allele of the prion protein gene in Italian Biellese ovine breed. J Gen Vir 85 (Oct) 10:3165-3172.
Alexander BM, Stobart RH, Russell WC, O’Rourke KI, Lewis GS, Logan JR, et al., (2005) The incidence of genotypes at condon 171 of the prion protein gene (PRNP) in five breeds of sheep and production traits of ewes associated with those genotypes. J Anim Sci 83: 455–459.
Arnold M., Meek C, Webb C R, Hoinville LJ (2002). Assessing the efficacy of a ram-genotyping programme to reduce susceptibility to scrapie in Great Britain. Prev Vet Med 56:227–249.
Billinis C, Psychas V, Leontides L, Spyrou V, Argyroudis S, Vlemmas I, Leontides S, Sklaviadis T, Papadopoulos O (2004). Prion protein gene polymorphisms in healthy and scrapie-affected sheep in Greece. J Gen Vir 85:547–554.
Bossers A, Schreuder BEC, Muileman I H, Belt PBGM, Smits MA (1996). PrP genotype contributes to determining survival times of sheep with natural scrapie. J Gen Vir 77:2669-2673, doi: 10.1099/0022-1317-77-10-2669.
Dawson M, Hoinville LJ, Hosie BD, Hunter N (1998).Guidance on the use of PrP genotyping as an aid to the control of clinical scrapie. Vet Rec 142:623–625.
DeSilva U, Guo X, Kupfer DM, Fernando SC, Pillai AT, Najar FZ, So S, Fitch GQ, Roe BA (2003). Allelic variants of ovine prion protein gene (PRNP) in Oklahoma sheep. Cytogenet. Genome Res 102:89-94.
Diaz-Avalos R, King C-Y, Wall J, Simon M, Caspar DLD (2005). Strainspecific morphologies of yeast prion amyloid fibrils. PNAS 102 (79):10165-10170.
Ekateriniadou LV, Kanata E, Panagiotidis C, Nikolaou A, Koutsoukou E, Lymberopoulos AG, Sklaviadis T (2007). PrP genotypes in scrapie-affected sheep in Greece. The contribution of the AHQ 1 polymorphism. Small Rum Res 73 (1-3): 142-149.
Ekateriniadou LV, Panagiotidis CH, Terzis A, Ploumi K, Triantafyllidis A, Deligiannidis P, Triantaphyllidis K, Sklaviadis T (2007). Sheep genotyping for PrP gene polymorphisms in rare Greek breeds. Vet Rec 160 (6):194-195.
Elsen JM, Amigues Y, Schelcher F, 7otherauthors (1999). Genetic susceptibility and transmission factors in scrapie: detailed analysis of an epidemic in a closed flock of Romanov. Arch Virol 144:431–445.
Goldmann W, Hunter N, Foster JD, Salbaum JM, Beyreuther K, Hope J (1990). Two alleles of a neural protein gene linked to scrapie in sheep. Proc Natl Acad Sci U S A. 87 (7):2476-2480.
Gombojav A, Ishiguro N, Horiuchi M, Serjmyadag D, Byambaa B, Shinagawa M (2003). Amino acid polymorphisms of PrP gene in Mongolian sheep. J Vet Med Sci, 65:75–81.
Hunter N, Foster JD, Goldmann W, Stear MJ, Hope J, Bostock C (1996). Natural scrapie in a closed flock of Cheviot sheep occurs only in specific PrP genotypes. Arch Vir 141: 809-824.
Leontides S, Psychas V, Argyroudis S, Giannati-Stefanou A, Paschaleri-Papadopoulou E, Manousis T, Sklaviadis T (2000). A survey of more than 11 years of neurologic diseases of ruminants with special refer ence to transmissible spongiform encephalopathies (TSEs) in Greece. J Vet Med Series B, 47:303-309.
Lühken G, Buschmann A, Groschup MH, Erhardt G (2004). Prion protein allele A136 H154 Q171 is associated with high susceptibility to scrapie in purebred and crossbred German Merinoland sheep. Arch Virol 149:1571–1580.
O’Doherty E, Healy A, Aherne M, Hanrahan JP, Weavers E, Doherty M, Roche JF, Gunn M, Sweeney T (2002). Prion protein (PrP) gene polymorphisms associated with natural scrapie cases and their flock-mates in Ireland. Res Vet Sci 73:243–250.
O’Rourke KI, Holyoak GR, Clark WW, Mickelson JR, Wang S, Melco RP, Besser TE, Foote WC (1997). PrP genotypes and experimental scrapie in orally inoculated Suffolk sheep in the United States. J Gen Vir 78:975-978.
Peter BGM, Belt PGM, Muileman IH, Schreuder BEC, Bos-de Ruijter J, Gielkens ALJ, Smits MA (1995). Identification of five allelic variants of the sheep PrP gene and their association with natural scrapie J Gen Virol 76:509-517, doi: 10.1099/0022-1317-76-3-509.
Prusiner SB (1998). Prions. Proc. Natl. Acad. Sci. USA 95: 13363-13383. Prusiner SB 1991. Molecular biology of prion disease. Science 252: 1515–1522.
Report on the monitoring and testing of ruminants for the presence of Transmissible Spongiform Encephalopathies (TSEs) in the EU in 2014. Health and Food Safety ISSN: 1725-583X
Thorgeirsdottir S, Sigurdarson S, Thorisson HM, Georgsson G, Palsdottir A (1999). PrP gene polymorphism and natural scrapie in Icelandic sheep. J Gen Virol 80:2527–2534.
Tranulis MA, Osland A, Bratberg B,Ulvand MJ (1999). Prion protein gene polymorphisms in sheep with natural scrapie and healthy controls in Norway. J Gen Virol 80:1073–1077