Genotype-level variation in lifetime breeding success, litter size and survival of sheep in scrapie-affected flocks Free

Abstract

Five different sheep flocks with natural outbreaks of scrapie were examined to determine associations between individual performance (lifetime breeding success, litter size and survival) and scrapie infection or PrP genotype. Despite different breed composition and forces of infection, consistent patterns were found among the flocks. Regardless of the flock, scrapie-infected sheep produced on average 34 % fewer offspring than non-scrapie-infected sheep. The effect of scrapie on lifetime breeding success appears to be a function of lifespan as opposed to fecundity. Analysis of litter size revealed no overall or genotype differences among the five sheep flocks. Survival, however, depends on the individual's scrapie status (infected or not) and its PrP genotype. Susceptible genotypes appear to perform less well in lifetime breeding success and life expectancy even if they are never affected with clinical scrapie. One possible explanation for these results is the effect of pre-clinical scrapie. Additional evidence supporting this hypothesis is discussed.

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2005-04-01
2024-03-29
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References

  1. Acín C., Martín-Burriel I., Goldmann W. 7 other authors 2004; Prion protein gene polymorphisms in healthy and scrapie-affected Spanish sheep. J Gen Virol 85:2103–2110 [CrossRef]
    [Google Scholar]
  2. Austin A. R., Simmons M. M. 1993; Reduced rumination in bovine spongiform encephalopathy and scrapie. Vet Rec 132:324–325 [CrossRef]
    [Google Scholar]
  3. Barillet F., Andréoletti O., Palhiere I. 12 other authors 2002; Breeding for scrapie resistance using PrP genotyping in the French dairy sheep breeds. In Proceedings of the 7th World Congress on Genetics Applied to Livestock Production Montpellier, France: 2002 pp  19–23
    [Google Scholar]
  4. Baylis M., Houston F., Goldmann W., Hunter N., McLean A. R. 2000; The signature of scrapie: differences in the PrP genotype profile of scrapie-affected and scrapie-free UK sheep flocks. Proc R Soc Lond B Biol Sci 267:2029–2035 [CrossRef]
    [Google Scholar]
  5. Baylis M., Goldmann W., Houston F., Cairns D., Chong A., Ross A., Smith A., Hunter N., McLean A. R. 2002; Scrapie epidemic in a fully PrP-genotyped sheep flock. J Gen Virol 83:2907–2914
    [Google Scholar]
  6. Bossers A., Schreuder B. E. C., Muileman I. H., Belt P. B. G. M., Smits M. A. 1996; PrP genotypes contributes to determining survival times of sheep with natural scrapie. J Gen Virol 77:2669–2673 [CrossRef]
    [Google Scholar]
  7. Brandsma J. H., Janss L. L. G., Visscher A. H. 2004; Association between PrP genotypes and littersize and 135 days weight in Texel sheep. Livest Prod Sci 85:59–64 [CrossRef]
    [Google Scholar]
  8. Clark A. M., Moar J. A. E. 1992; Scrapie: a clinical assessment. Vet Rec 130:377–378 [CrossRef]
    [Google Scholar]
  9. Clouscard C., Beaudry P., Elsen J.-M. 7 other authors 1995; Different allelic effects of the codons 136 and 171 of the prion protein gene in sheep with natural scrapie. J Gen Virol 76:2097–2101 [CrossRef]
    [Google Scholar]
  10. Collett D. 2003 In Modelling Survival Data in Medical Research , 2nd edn. London: Chapman & Hall;
    [Google Scholar]
  11. Dawson M., Hoinville L. J., Hosie B. D., Hunter N. 1998; Guidance on the use of PrP genotyping as an aid to the control of clinical scrapie. Vet Rec 142:623–625
    [Google Scholar]
  12. de Vries F., Borchers N., Hamann H., Drogemuller C., Reinecke S., Lupping W., Distl O. 2004; Associations between prion protein genotype and performance traits of meat breeds of sheep. Vet Rec 155:140–143 [CrossRef]
    [Google Scholar]
  13. Drogemuller C., Leeb T., Distl O. 2001; PrP genotype frequencies in German breeding sheep and the potential to breed for resistance to scrapie. Vet Rec 149:349–352 [CrossRef]
    [Google Scholar]
  14. Elsen J. M., Amigues Y., Schelcher F. 7 other authors 1999; Genetic susceptibility and transmission factors in scrapie: detailed analysis of an epidemic in a closed flock of Romanov. Arch Virol 144:431–445 [CrossRef]
    [Google Scholar]
  15. Goldmann W., Hunter N., Benson G., Foster J. D., Hope J. 1991; Different scrapie-associated fibril proteins (PrP) are encoded by lines of sheep selected for different alleles of the Sip gene. J Gen Virol 72:2411–2417 [CrossRef]
    [Google Scholar]
  16. Goldmann W., Hunter N., Smith G., Foster J., Hope J. 1994; PrP genotype and agent effects in scrapie: change in allelic interaction with different isolates of agent in sheep, a natural host of scrapie. J Gen Virol 75:989–995 [CrossRef]
    [Google Scholar]
  17. Humphry R. W., Clark A. M., Begara-McGorum I., Gunn G. J. 2004; Estimation of scrapie prevalence in cull and found-dead sheep on the Shetland Islands. Vet Rec 154:303–304 [CrossRef]
    [Google Scholar]
  18. Hunter N. 1997; PrP genetics in sheep and the applications for scrapie and BSE. Trends Microbiol 5:331–334 [CrossRef]
    [Google Scholar]
  19. Hunter N., Foster J. D., Goldmann W., Stear M. J., Hope J., Bostock C. 1996; Natural scrapie in a closed flock of Cheviot sheep occurs only in specific PrP genotypes. Arch Virol 141:809–824 [CrossRef]
    [Google Scholar]
  20. Hunter N., Moore L., Hosie B. D., Dingwall W. S., Greig A. 1997; Association between natural scrapie and PrP genotype in a flock of Suffolk sheep in Scotland. Vet Rec 140:59–63 [CrossRef]
    [Google Scholar]
  21. McLean A. R., Hoek A., Hoinville L. J., Gravenor M. B. 1999; Scrapie transmission in Britain: a recipe for a mathematical model. Proc R Soc Lond B Biol Sci 266:2531–2538 [CrossRef]
    [Google Scholar]
  22. Parry H. B. 1983 Scrapie disease in sheep London: Academic Press;
    [Google Scholar]
  23. Prokopova L., Lewis R. M., Dingwall W. S., Simm G. 2002; Scrapie genotype: a correlation with lean growth rate?. In Proceedings of the 7th World Congress on Genetics Applied to Livestock Production Montpellier, France. 2002 pp  19–23
    [Google Scholar]
  24. Redman C. A., Coen P. G., Matthews L., Lewis R. M., Dingwall W. S., Foster J. D., Chase-Topping M. E., Hunter N., Woolhouse M. E. J. 2002; Comparative epidemiology of scrapie outbreaks in individual sheep flocks. Epidemiol Infect 128:513–521
    [Google Scholar]
  25. Roden J. A., Haresign W., Anderson J. M. L. 2001; Analysis of PrP genotype in relation to performance traits in Suffolk sheep. In British Society of Animal Science: Proceedings of the Annual Meeting p– 45
    [Google Scholar]
  26. Schreuder B. E. C., van Keulen L. J. M., Vromans M. E. W., Langeveld J. P. M., Smits M. A. 1998; Tonsillar biopsy and PrPSc detection in the preclinical diagnosis of scrapie. Vet Rec 142:564–568 [CrossRef]
    [Google Scholar]
  27. Stamp J. T. 1962; Scrapie: a transmissible disease of sheep. Vet Rec 74:357–362
    [Google Scholar]
  28. Thorgeirsdottir S., Georgsson G., Reynisson E., Sigurdarson S., Palsdottir A. 2002; Search for healthy carriers of scrapie: an assessment of subclinical infection of sheep in an Icelandic scrapie flock by three diagnostic methods and correlation with PrP genotypes. Arch Virol 147:709–722 [CrossRef]
    [Google Scholar]
  29. Vaccari G., Petraroli R., Agrimi U. 8 other authors 2001; PrP genotype in Sarda breed sheep and its relevance to scrapie. Arch Virol 146:2029–2037 [CrossRef]
    [Google Scholar]
  30. Wilesmith J. W., Hoinville L. J., Ryan J. B. M., Sayers A. R. 1992; Bovine spongiform encephalopathy: aspects of the clinical picture and analysis of possible changes 1986–1990. Vet Rec 130:197–201 [CrossRef]
    [Google Scholar]
  31. Williams E. S., Young S. 1982; Spongiform encephalopathy of Rocky Mountain elk. J Wildl Dis 18:465–471 [CrossRef]
    [Google Scholar]
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