Opinion of the Scientific Panel on biological hazards (BIOHAZ) on the Breeding programme for TSE resistance in sheep

EFSA Journal

Volumn 4, Issue 7, 2006, Pages

[No Author Info available]

Author keywords

Atypical scrapie; Breeding programme; BSE; Resistance; Scrapie; Sheep

Indexed keywords

EID: 85078392710     PISSN: None     EISSN: 18314732     Source Type: Journal    
DOI: 10.2903/j.efsa.2006.382     Document Type: Article

References (139)

1. Acin, C., I. Martin-Burriel, W. Goldmann, J. Lyahyai, M. Monzon, R. Bolea, A. Smith, C. Rodellar, J. J. Badiola and P. Zaragoza (2004). “Prion protein gene polymorphisms in healthy and scrapie-affected Spanish sheep.” J Gen Virol 85(Pt 7): 2103–10.
2. AFSSA (2005). “Avis du Comité sur l'analyse des risques lies aux encéphalopathies spongiformes transmissibles dans les filieres petits ruminants, les forces et faiblesses du dispositif actuel et les possibilités d'evolution. Actualisation en mars 2005 de l'avis de décembre 2001.” Afssa - Saisine n° 2004-SA-0390.
3. Amyx, H. L., C. J. Gibbs, Jr., D. C. Gajdusek and W. E. Greer (1981). “Absence of vertical transmission of subacute spongiform viral encephalopathies in experimental primates.” Proc Soc Exp Biol Med 166(4): 469–71.
4. Andreoletti, O., P. Berthon, D. Marc, P. Sarradin, J. Grosclaude, L. van Keulen, F. Schelcher, J. M. Elsen and F. Lantier (2000). “Early accumulation of PrP(Sc) in gut-associated lymphoid and nervous tissues of susceptible sheep from a Romanov flock with natural scrapie.” J Gen Virol 81(Pt 12): 3115–26.
5. Andreoletti, O., N. Morel, C. Lacroux, V. Rouillon, C. Barc, G. Tabouret, P. Sarradin, P. Berthon, P. Bernardet, J. Mathey, S. Lugan, P. Costes, F. Corbiere, J. C. Espinosa, J. M. Torres, J. Grassi, F. Schelcher and F. Lantier (2006). “Bovine spongiform encephalopathy agent in spleen from an ARR/ARR orally exposed sheep.” J Gen Virol 87(Pt 4): 1043–6.
6. Baylis, M. (2002). “The BSE-susceptible proportion of UK sheep.” Vet Rec 151(16): 481–2.
7. Baylis, M., F. Houston, R. R. Kao, A. R. McLean, N. Hunter and M. B. Gravenor (2002). “BSE - a wolf in sheep's clothing?” Trends Microbiol 10(12): 563–70.
8. Baylis, M. and K. M. McIntyre (2004). “Transmissible spongiform encephalopathies: scrapie control under new strain.” Nature 432(7019): 810–1.
9. Bellworthy, S. J., S. A. Hawkins, R. B. Green, I. Blamire, G. Dexter, I. Dexter, R. Lockey, M. Jeffrey, S. Ryder, C. Berthelin-Baker and M. M. Simmons (2005). “Tissue distribution of bovine spongiform encephalopathy infectivity in Romney sheep up to the onset of clinical disease after oral challenge.” Vet Rec 156(7): 197–202.
10. Belt, P. B., I. H. Muileman, B. E. Schreuder, J. Bos-de Ruijter, A. L. Gielkens and M. A. Smits (1995). “Identification of five allelic variants of the sheep PrP gene and their association with natural scrapie.” J Gen Virol 76(Pt 3): 509–17.
11. Benestad, S. L., P. Sarradin, B. Thu, J. Schonheit, M. A. Tranulis and B. Bratberg (2003). “Cases of scrapie with unusual features in Norway and designation of a new type, Nor98.” Vet Rec 153(7): 202–8.
12. Billinis, C., V. Psychas, L. Leontides, V. Spyrou, S. Argyroudis, I. Vlemmas, S. Leontides, T. Sklaviadis and O. Papadopoulos (2004). “Prion protein gene polymorphisms in healthy and scrapie-affected sheep in Greece.” J Gen Virol 85(Pt 2): 547–54.
13. Bossers, A., B. E. Schreuder, I. H. Muileman, P. B. Belt and M. A. Smits (1996). “PrP genotype contributes to determining survival times of sheep with natural scrapie.” J Gen Virol 77 (Pt 10): 2669–73.
14. Buschmann, A., A. G. Biacabe, U. Ziegler, A. Bencsik, J. Y. Madec, G. Erhardt, G. Luhken, T. Baron and M. H. Groschup (2004). “Atypical scrapie cases in Germany and France are identified by discrepant reaction patterns in BSE rapid tests.” J Virol Methods 117(1): 27–36.
15. Buschmann, A., G. Luhken, J. Schultz, G. Erhardt and M. H. Groschup (2004). “Neuronal accumulation of abnormal prion protein in sheep carrying a scrapie-resistant genotype (PrPARR/ARR).” J Gen Virol 85(Pt 9): 2727–33.
16. Clouscard, C., P. Beaudry, J. M. Elsen, D. Milan, M. Dussaucy, C. Bounneau, F. Schelcher, J. Chatelain, J. M. Launay and J. L. Laplanche (1995). “Different allelic effects of the codons 136 and 171 of the prion protein gene in sheep with natural scrapie.” J Gen Virol 76 (Pt 8): 2097–101.
17. De Bosschere, H., S. Roels, S. L. Benestad and E. Vanopdenbosch (2004). “Scrapie case similar to Nor98 diagnosed in Belgium via active surveillance.” Vet Rec 155(22): 707–8.
18. DeSilva, U., X. Guo, D. M. Kupfer, S. C. Fernando, A. T. Pillai, F. Z. Najar, S. So, G. Q. Fitch and B. A. Roe (2003). “Allelic variants of ovine prion protein gene (PRNP) in Oklahoma sheep.” Cytogenet Genome Res 102(1–4): 89–94.
19. Detwiler, L. A. and M. Baylis (2003). “The epidemiology of scrapie.” Rev Sci Tech 22(1): 121–43.
20. Diekmann, O., J. A. Heesterbeek and J. A. Metz (1990). “On the definition and the computation of the basic reproduction ratio R0 in models for infectious diseases in heterogeneous populations.” J Math Biol 28(4): 365–82.
21. Drögemüller, C., F. de Vries, H. Hamann, T. Leeb and O. Distl (2004). “Breeding German sheep for resistance to scrapie.” Vet Rec 154(9): 257–60.
22. EFSA (2003). “EFSA Opinion on ‘The interpretation of results of EU Surveillance of transmissible spongiform encephalopathies (TSEs) in ovine and caprine animals, culling strategies for TSEs in small ruminants and the TSE-related safety of certain small ruminant products’.” The EFSA Journal 12: 1–6.
23. EFSA (2005a). “Scientific Report of the European Food Safety Authority on the Evaluation of Rapid post mortem TSE Tests intended for Small Ruminants.” The EFSA Journal 31: 1–17.
24. EFSA (2005b). “Scientific Report of the European Food Safety Authority on the Evaluation of Rapid post mortem TSE Tests intended for Small Ruminants.” The EFSA Journal 49: 1–16.
25. EFSA (2005c). “EFSA Opinion on ‘Classification of atypical Transmissible Spongiform Encephalopathy (TSE) cases in small ruminants’.” The EFSA Journal 276: 1–30.
26. EFSA (2005d). “Opinion of the Scientific Panel on Biological Hazards of the European Food Safety Authority on the usefulness of somatic cell counts for safety of milk and milk derived products from goats.” The EFSA Journal 305: 1–19.
27. Elsen, J. M., Y. Amigues, F. Schelcher, V. Ducrocq, O. Andreoletti, F. Eychenne, J. V. Khang, J. P. Poivey, F. Lantier and J. L. Laplanche (1999). “Genetic susceptibility and transmission factors in scrapie: detailed analysis of an epidemic in a closed flock of Romanov.” Arch Virol 144(3): 431–45.
28. Epstein, V., S. Pointing and S. Halfacre (2005). “Atypical scrapie in the Falkland Islands.” Vet Rec 157(21): 667–8.
29. EU (2001). “Regulation (EC) No 999/2001 of the European Parliament and of the Council of 22 May 2001 laying down rules for the prevention, control and eradication of certain transmissible spongiform encephalopathies.” Official Journal of the European Union 147: 1–40.
30. EU (2002). “Commission Decision of 18 December 2002 laying down minimum requirements for a survey of prion protein genotypes of sheep breeds (Text with EEA relevance) (notified under document number C(2002) 5102).” Official Journal of the European Union 349: 105–107.
31. EU (2003). “Commission Decision of 13 February 2003 laying down minimum requirements for the establishment of breeding programmes for resistance to transmissible spongiform encephalopathies in sheep.” Official Journal of the European Union 41: 41–45.
32. Ferguson, N. M., A. C. Ghani, C. A. Donnelly, T. J. Hagenaars and R. M. Anderson (2002). “Estimating the human health risk from possible BSE infection of the British sheep flock.” Nature 415(6870): 420–4.
33. Foster, J. D., D. Parnham, A. Chong, W. Goldmann and N. Hunter (2001). “Clinical signs, histopathology and genetics of experimental transmission of BSE and natural scrapie to sheep and goats.” Vet Rec 148(6): 165–71.
34. Gavier-Widen, D., M. Noremark, S. Benestad, M. Simmons, L. Renstrom, B. Bratberg, M. Elvander and C. H. af Segerstad (2004). “Recognition of the Nor98 variant of scrapie in the Swedish sheep population.” J Vet Diagn Invest 16(6): 562–7.
35. Gibbs, C. J., Jr., H. L. Amyx, A. Bacote, C. L. Masters and D. C. Gajdusek (1980). “Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.” J Infect Dis 142(2): 205–8.
36. Gibbs, C. J., Jr. and D. C. Gajdusek (1972). “Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).” Nature 236(5341): 73–4.
37. Goldmann, W., M. Baylis, C. Chihota, E. Stevenson and N. Hunter (2005). “Frequencies of PrP gene haplotypes in British sheep flocks and the implications for breeding programmes.” J Appl Microbiol 98(6): 1294–302.
38. Goldmann, W., N. Hunter, J. D. Foster, J. M. Salbaum, K. Beyreuther and J. Hope (1990). “Two alleles of a neural protein gene linked to scrapie in sheep.” Proc Natl Acad Sci U S A 87(7): 2476–80.
39. Goldmann, W., N. Hunter, T. Martin, M. Dawson and J. Hope (1991). “Different forms of the bovine PrP gene have five or six copies of a short, G-C-rich element within the protein-coding exon.” J Gen Virol 72 (Pt 1): 201–4.
40. Goldmann, W., N. Hunter, G. Smith, J. Foster and J. Hope (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 (Pt 5): 989–95.
41. Gombojav, A., N. Ishiguro, M. Horiuchi, D. Serjmyadag, B. Byambaa and M. Shinagawa (2003). “Amino acid polymorphisms of PrP gene in Mongolian sheep.” J Vet Med Sci 65(1): 75–81.
42. Gonzalez, L., S. Martin, F. E. Houston, N. Hunter, H. W. Reid, S. J. Bellworthy and M. Jeffrey (2005). “Phenotype of disease-associated PrP accumulation in the brain of bovine spongiform encephalopathy experimentally infected sheep.” J Gen Virol 86(Pt 3): 827–38.
43. Gravenor, M. B., S. J. Ryder, S. Gubbins, N. Hunter, M. Baylis and R. R. Kao (2003). “Searching for BSE in sheep: interpreting the results so far.” Vet Rec 152(10): 298–9.
44. Gubbins, S. (2005). “A modelling framework to describe the spread of scrapie between sheep flocks in Great Britain.” Prev Vet Med 67(2–3): 143–56.
45. Gubbins, S. and J. A. Roden (2006). “Breeding programmes for TSE resistance in British sheep. II. Assessing the impact on the prevalence and incidence of scrapie.” Prev Vet Med 73(1): 17–31.
46. Guo, X., D. M. Kupfer, G. Q. Fitch, B. A. Roe and U. DeSilva (2003). “Identification of a novel lysine-171 allele in the ovine prion protein (PRNP) gene.” Anim Genet 34(4): 303–5.
47. Heaton, M. P., K. A. Leymaster, B. A. Freking, D. A. Hawk, T. P. Smith, J. W. Keele, W. M. Snelling, J. M. Fox, C. G. Chitko-McKown and W. W. Laegreid (2003). “Prion gene sequence variation within diverse groups of U.S. sheep, beef cattle, and deer.” Mamm Genome 14(11): 765–77.
48. Heggebo, R., C. M. Press, G. Gunnes, L. Gonzalez and M. Jeffrey (2002). “Distribution and accumulation of PrP in gut-associated and peripheral lymphoid tissue of scrapie-affected Suffolk sheep.” J Gen Virol 83(Pt 2): 479–89.
49. Hill, A. F., S. Joiner, J. Linehan, M. Desbruslais, P. L. Lantos and J. Collinge (2000). “Species-barrier-independent prion replication in apparently resistant species.” Proc Natl Acad Sci U S A 97(18): 10248–53.
50. Houston, F., W. Goldmann, A. Chong, M. Jeffrey, L. Gonzalez, J. Foster, D. Parnham and N. Hunter (2003). “Prion diseases: BSE in sheep bred for resistance to infection.” Nature 423(6939): 498.
51. Hunter, N., W. Goldmann, J. D. Foster, D. Cairns and G. Smith (1997). “Natural scrapie and PrP genotype: case-control studies in British sheep.” Vet Rec 141(6): 137–40.
52. Jeffrey, M., I. Begara-McGorum, S. Clark, S. Martin, J. Clark, M. Chaplin and L. Gonzalez (2002). “Occurrence and distribution of infection-specific PrP in tissues of clinical scrapie cases and cull sheep from scrapie-affected farms in Shetland.” J Comp Pathol 127(4): 264–73.
53. Jeffrey, M., S. Ryder, S. Martin, S. A. Hawkins, L. Terry, C. Berthelin-Baker and S. J. Bellworthy (2001). “Oral inoculation of sheep with the agent of bovine spongiform encephalopathy (BSE). 1. Onset and distribution of disease-specific PrP accumulation in brain and viscera.” J Comp Pathol 124(4): 280–9.
54. Kao, R. R., M. B. Gravenor, M. Baylis, C. J. Bostock, C. M. Chihota, J. C. Evans, W. Goldmann, A. J. Smith and A. R. McLean (2002). “The potential size and duration of an epidemic of bovine spongiform encephalopathy in British sheep.” Science 295(5553): 332–5.
55. Kao, R. R., F. Houston, M. Baylis, C. M. Chihota, W. Goldmann, M. B. Gravenor, N. Hunter and A. R. McLean (2003). “Epidemiological implications of the susceptibility to BSE of putatively resistant sheep.” J Gen Virol 84(Pt 12): 3503–12.
56. Laplanche, J. L., J. Chatelain, P. Beaudry, M. Dussaucy, C. Bounneau and J. M. Launay (1993). “French autochthonous scrapied sheep without the 136Val PrP polymorphism.” Mamm Genome 4(8): 463–4.
57. Laude, H. (2006). “Biological characterisation of isolates in transgenic models.” Proceedings of the International Conference on ‘Prion Diseases of Domestic Livestock’: 48.
58. Le Dur, A., V. Beringue, O. Andreoletti, F. Reine, T. L. Lai, T. Baron, B. Bratberg, J. L. Vilotte, P. Sarradin, S. L. Benestad and H. Laude (2005). “A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes.” Proc Natl Acad Sci U S A 102(44): 16031–6.
59. Luehken, G., A. Buschmann, H. Brandt, M. Eiden, M. H. Groschup and G. Erhardt (2006). “Epidemiological and genetical differences between classical and Nor98-like atypical scrapie cases in Germany.” submitted.
60. Moum, T., I. Olsaker, P. Hopp, T. Moldal, M. Valheim, T. Moum and S. L. Benestad (2005). “Polymorphisms at codons 141 and 154 in the ovine prion protein gene are associated with scrapie Nor98 cases.” J Gen Virol 86(Pt 1): 231–5.
61. O'Rourke, K. I., T. V. Baszler, T. E. Besser, J. M. Miller, R. C. Cutlip, G. A. Wells, S. J. Ryder, S. M. Parish, A. N. Hamir, N. E. Cockett, A. Jenny and D. P. Knowles (2000). “Preclinical diagnosis of scrapie by immunohistochemistry of third eyelid lymphoid tissue.” J Clin Microbiol 38(9): 3254–9.
62. Onnasch, H., H. M. Gunn, B. J. Bradshaw, S. L. Benestad and H. F. Bassett (2004). “Two Irish cases of scrapie resembling Nor98.” Vet Rec 155(20): 636–7.
63. Orge, L., A. Galo, C. Machado, C. Lima, C. Ochoa, J. Silva, M. Ramos and J. P. Simas (2004). “Identification of putative atypical scrapie in sheep in Portugal.” J Gen Virol 85(Pt 11): 3487–91.
64. Roden, J. A., G. J. Nieuwhof, S. C. Bishop, D. A. Jones, W. Haresign and S. Gubbins (2006). “Breeding programmes for TSE resistance in British sheep. I. Assessing the impact on prion protein (PrP) genotype frequencies.” Prev Vet Med 73(1): 1–16.
65. Saunders, G. C. S., Cawthraw, M. S.J., J. Hope and O. Wildl (2006). “PrP genotype of atypical scrapie cases in Great Britain.” in press.
66. Seabury, C. M. and J. N. Derr (2003). “Identification of a novel ovine PrP polymorphism and scrapie-resistant genotypes for St. Croix White and a related composite breed.” Cytogenet Genome Res 102(1–4): 85–8.
67. Slate, J. (2005). “Molecular evolution of the sheep prion protein gene.” Proc Biol Sci 272(1579): 2371–7.
68. Soller, M. and A. Genizi (1978). “The efficiency of experimental designs for the detection of linkage between a marker locus and a locus affecting a quantitative trait in segregating populations.” Biometrics 34: 7–55.
69. SSC (1999). “Opinion of the Scientific Steering Committee on ‘The policy of breeding and genotyping of sheep, i.e. The issue of whether sheep should be bred to be resistant to scrapie’.”
70. SSC (2001a). “Opinion of the Scietific Steering Committee on ‘The safety of small ruminant products should BSE in small ruminants become probable / confirmed’.”
71. SSC (2002a). “Opinion of the Scientific Steering Committee on ‘Strategy to investigate the possible presence of BSE in sheep’.”
72. SSC (2002b). “Opinion of the Scientific Steering Committee on ‘Safe sourcing of small ruminant materials (Safe sourcing of small ruminant materials should BSE in small ruminants become probable: genotype, breeding, rapid TSE testing, flocks certification and Specified Risk Materials)’.”
73. Stack, M., M. Jeffrey, S. Gubbins, S. Grimmer, L. Gonzalez, S. Martin, M. Chaplin, P. Webb, M. Simmons, Y. Spencer, P. Bellerby, J. Hope, J. Wilesmith and D. Matthews (2006). “Monitoring for bovine spongiform encephalopathy in sheep in Great Britain, 1998–2004.” J Gen Virol 87(Pt 7): 2099–107.
74. Thorgeirsdottir, S., S. Sigurdarson, H. M. Thorisson, G. Georgsson and A. Palsdottir (1999). “PrP gene polymorphism and natural scrapie in Icelandic sheep.” J Gen Virol 80 (Pt 9): 2527–34.
75. Tranulis, M. A., A. Osland, B. Bratberg and M. J. Ulvund (1999). “Prion protein gene polymorphisms in sheep with natural scrapie and healthy controls in Norway.” J Gen Virol 80 (Pt 4): 1073–7.
76. Windig, J. J., H. Eding, L. Moli and L. Kaal (2004). “Effects on inbreeding of different strategies aimed at eliminating scrapie sensitivity alleles in rare sheep bredds in The Netherlands.” Animal Science 79: 11–20.
77. Alfonso, L., A. Parada, A. Legarra, E. Ugarte and A. Arana (2006). “Effects on genetic variability of selection against scrapie sensitivity in the Latxa Black-faced sheep.” submitted.
78. Arnold, M., C. Meek, C. R. Webb and L. J. Hoinville (2002). “Assessing the efficacy of a ram-genotyping programme to reduce susceptibility to scrapie in Great Britain.” Prev Vet Med 56(3): 227–49.
79. Barillet, F., I. Palhière, J. M. Astruc, M. Brochard, M. Baelden, X. Aguerre, F. Fidele, J. M. Arranz, J. P. Belloc, M. Briois, G. Frégeat, C. Soulas, O. Andreoletti, F. Corbière and F. Schelcher (2004). “Le programme français d'éradication de la tremblante du cheptel ovin fondé sur l'utilisation de la génétique.” INRA Prod Anim(Numéro hors série): 87–100.
80. Baumung, R. and J. Solkner (2003). “Pedigree and marker information requirements to monitor genetic variability.” Genet Sel Evol 35(4): 369–83.
81. Brochard, M. and I. Palhière (2004). “Side effects on genetic merit of the French breeding programme for scrapie resistance in Berrichon du Cher, Causes du Lot and Mouton Charollais breeds.” Rencontre Recherche Ruminants.
82. Caballero, A. and M. A. Toro (2002). “Analysis of genetic diversity for the management of conserved subdivised populations.” Conserv Genet 3: 289–299.
83. Dekkers, J. C. M. and J. A. M. Van Arendonk (1998) “Utilizing selection for quantitative traits with information on an identified locus in outbred populations.” Genet Res 71: 257–275.
84. Grundy, B. Villanueva and J. A. Wolliams (1998) “Dynamic selection procedures for constrained inbreeding and their consequences for pedigree development.” Genet Res 72: 159–168.
85. Gubbins, S. and C. R. Webb (2005). “Simulation of the options for a national control programme to eradicate scrapie from Great Britain.” Prev Vet Med 69(3–4): 175–87.
86. Larzul, C., E. Manfredi and J. M. Elsen (1997). “Potential gain from including major gene information in breeding value estimation.” Genet Sel Evol 29: 161–184.
87. Meuwissen, T. H. (1997). “Maximizing the response of selection with a predefined rate of inbreeding.” J Anim Sci 75(4): 934–40.
88. Meuwissen, T. H. and A. K. Sonesson (1998). “Maximizing the response of selection with a predefined rate of inbreeding: overlapping generations.” J Anim Sci 76(10): 2575–83.
89. Palhière, I., M. Brochard, E. Verrier, K. Moazami-Goudarzi, Y. Amigues, F. Barillet, B. Bed Hom, B. Bibé, J. Bouix, D. François, C. Leymarie and T. Pantano (2006). “Did the selection for scrapie resistance impact the genetic variability? Preliminary results on four French sheep breeds.” in press.
90. Sonesson, A. K., L. L. Janss and T. H. Meuwissen (2003) “Selection against genetic defects in conservation schemes while controlling inbreeding.” Genet Sel Evol 35(4): 353–68.
91. Sonesson, A. K. and T. H. Meuwissen (2000). “Mating schemes for optimum contribution selection with constrained rates of inbreeding.” Genet Sel Evol 32(3): 231–48.
92. Villanueva, B., R. Pong-Wong and J. A. Woolliams (2002) “Marker assisted selection with optimised contributions of the candidates to selection.” Genet Sel Evol 34(6): 679–703.
93. Windig, J. J., H. Eding, L. Moli and L. Kaal (2004) “Effects on inbreeding of different strategies aimed at eliminating scrapie sensitivity alleles in rare sheep bredds in The Netherlands.” Animal Science 79: 11–20.
94. Alexander, B. M., R. H. Stobart, et al. (2005). “The incidence of genotypes at codon 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(2): 455–9.
95. Ashwell, M. S., D. W. Heyen, et al. (2005). “Detection of quantitative trait loci influencing conformation traits and calving ease in Holstein-Friesian cattle.” J Dairy Sci 88(11): 4111–9.
96. Barillet, F., O. Andreoletti, et al. (2002). “Breeding for scrapie resistance using PrP genotyping in the French dairy sheep population.” Proc. 7th WCGALP: 13–20.
97. Barillet, F., J. J. Arranz, et al. (2005). “Mapping quantitative trait loci for milk production and genetic polymorphisms of milk proteins in dairy sheep.” Genet Sel Evol 37 Suppl 1: S109–23.
98. Barillet, F., A. Carta, et al. (2003). “Détection de QTL influençant des caractères d□importance économiue présente ou à venire en ovins laitiers en France et en Italie.” Rencontre Recherche Ruminants 2003 10: 57–60.
99. Beh, K. J., M. J. Callaghan, et al. (2001). “A genome scan for QTL affecting fleece and wool traits in Merino sheep.” Int J Sheep and wool sci 49(21): 88–97.
100. Beh, K. J., D. J. Hulme, et al. (2002). “A genome scan for quantitative trait loci affecting resistance to Trichostrongylus colubriformis in sheep.” Anim Genet 33(2): 97–106.
101. Boichard, D., C. Grohs, et al. (2003). “Detection of genes influencing economic traits in three French dairy cattle breeds.” Genet Sel Evol 35(1): 77–101.
102. Bonnet, E., J. M. Elsen, et al. (2004). “Estudio de Asociacion entre el gen PrP y la fertilidad de machos de la raza Lacaune.” XII reunion Nacional de Melora Genetica Animal.
103. Brandsma, J. H., L. L. H. Janss, et al. (2004). “Association between PrP genotypes and littersize and 135 days weight in Texel sheep.” Livest.Prod.Sci. 85: 59–64.
104. Brandsma, J. H., L. L. H. Janss, et al. (2005). “Association between PrP genotypes and performance traits in an experimental Dutch Texel herd.” Livest.Prod.Sci. 95: 89–94.
105. Casas, E., S. D. Shackelford, et al. (2003). “Detection of quantitative trait loci for growth and carcass composition in cattle.” J Anim Sci 81(12): 2976–83.
106. Casellas, J., J. Piedrafita, et al. (2005). “Association analyses between the prion protein locus and reproductive and weight traits in Ripollesa sheep.” J. Anim. Sci. 83(1): 230.
107. De Vries, F., H. Hamann, et al. (2005). “Analysis of associations between the prion protein genotypes and production traits in East Friesian milk sheep.” J Dairy Sci 88(1): 392–8.
108. De Vries, F., H. Hamann, et al. (2004). “Einfluss der Prion protein gen polymorphismen auf Leistungsmerkmale bei deutschen Fleischschafrassen.” Dtsch. Tierârztl. Wschr. 111: 349–354.
109. Georges, M., D. Nielsen, et al. (1995). “Mapping quantitative trait loci controlling milk production in dairy cattle by exploiting progeny testing.” Genetics 139(2): 907–20.
110. Heyen, D. W., J. I. Weller, et al. (1999). “A genome scan for QTL influencing milk production and health traits in dairy cattle.” Physiol Genomics 1(3): 165–75.
111. Hiendleder, S., H. Thomsen, et al. (2003). “Mapping of QTL for Body Conformation and Behavior in Cattle.” J Hered 94(6): 496–506.
112. Holmberg, M. and L. Andersson-Eklund (2004). “Quantitative trait loci affecting health traits in Swedish dairy cattle.” J Dairy Sci 87(8): 2653–9.
113. Klungland, H., A. Sabry, et al. (2001). “Quantitative trait loci affecting clinical mastitis and somatic cell count in dairy cattle.” Mamm Genome 12(11): 837–42.
114. Kuhn, C., J. Bennewitz, et al. (2003). “Quantitative trait loci mapping of functional traits in the German Holstein cattle population.” J Dairy Sci 86(1): 360–8.
115. Lien, S., A. Karlsen, et al. (2000). “A primary screen of the bovine genome for quantitative trait loci affecting twinning rate.” Mamm Genome 11(10): 877–82.
116. MacNeil, M. D. and M. D. Grosz (2002). “Genome-wide scans for QTL affecting carcass traits in Hereford × composite double backcross populations.” J Anim Sci 80(9): 2316–24.
117. Mizoguchi, Y., T. Watanabe, et al. (2006). “Mapping of quantitative trait loci for carcass traits in a Japanese Black (Wagyu) cattle population.” Anim Genet 37(1): 51–4.
118. Mizoshita, K., T. Watanabe, et al. (2004). “Quantitative trait loci analysis for growth and carcass traits in a half-sib family of purebred Japanese Black (Wagyu) cattle.” J Anim Sci 82(12): 3415–20.
119. Mosig, M. O., E. Lipkin, et al. (2001). “A whole genome scan for quantitative trait loci affecting milk protein percentage in Israeli-Holstein cattle, by means of selective milk DNA pooling in a daughter design, using an adjusted false discovery rate criterion.” Genetics 157(4): 1683–98.
120. Moum, T., I. Olsaker, et al. (2005). “Polymorphisms at codons 141 and 154 in the ovine prion protein gene are associated with scrapie Nor98 cases.” J Gen Virol 86(Pt 1): 231–5.
121. Nicholls N (2006). “Are scrapie-susceptible sheep more productive?” PhD thesis, University of Edinburgh.
122. Olsen, H. G., L. Gomez-Raya, et al. (2002). “A genome scan for quantitative trait loci affecting milk production in Norwegian dairy cattle.” J Dairy Sci 85(11): 3124–30.
123. Ponz, R., C. Moreno, et al. (2001). “Assessment of genetic variation explained by markers for wool traits in sheep via a segment mapping approach.” Mammalian genome 12: 569–572.
124. Ponz, R., M. T. Tejedor, et al. (2006). “Scrapie resistance alleles are not associated with lower prolificity in Rasa Aragonesa sheep.” Res Vet Sci 81(1): 37–9.
125. Prokopova, L., R. M. Lewis, et al. (2002). “Scrapie genotype: a correlation with lean growth rate?” Proc. 7th WCGALP: 13–44.
126. Roden, J. A., W. Haresign, et al. (2001). “Analysis of PrP genotype in relation to performance traits in Suffolk sheep.” Proc. Brit. Soc. Anim. Sci. 2001: 45.
127. Ron, M., E. Feldmesser, et al. (2004). “A complete genome scan of the Israeli Holstein population for quantitative trait loci by a daughter design.” J Dairy Sci 87(2): 476–90.
128. Rupp, R., L. Schibler, et al. (2003). “Evidence of chromosomal regions controlling somatic cell counts in dairy sheep from two QTL detection projects.” International Workshop on Major Genes and QTL in Sheep and Goats.
129. Schrooten, C., H. Bovenhuis, et al. (2000). “Whole genome scan to detect quantitative trait loci for conformation and functional traits in dairy cattle.” J Dairy Sci 83(4): 795–806.
130. Schulman, N. F., S. M. Viitala, et al. (2004). “Quantitative trait Loci for health traits in Finnish Ayrshire cattle.” J Dairy Sci 87(2): 443–9.
131. Spelman, R. J., A. E. Huisman, et al. (1999). “Short communication: quantitative trait loci analysis on 17 nonproduction traits in the New Zealand dairy population.” J Dairy Sci 82(11): 2514–6.
132. Viitala, S. M., N. F. Schulman, et al. (2003). “Quantitative trait loci affecting milk production traits in Finnish Ayrshire dairy cattle.” J Dairy Sci 86(5): 1828–36.
133. Vitezica, Z. G., C. R. Moreno, et al. (2006). “No associations between PrP genotypes and reproduction traits in INRA 401 sheep.” J Anim Sci 84(6): 1317–22.
134. Vitezica, Z. G., C. R. Moreno, et al. (2005). “A study on associations between PrP genotypes and meat traits in French sheep breeds.” Anim. Sci. 81: 325–330.
135. Zhang, C., D. J. De Koning, et al. (2004). “Mapping of multiple quantitative trait loci affecting bovine spongiform encephalopathy.” Genetics 167(4): 1863–72.
136. Zhang, Q., D. Boichard, et al. (1998). “Mapping quantitative trait loci for milk production and health of dairy cattle in a large outbred pedigree.” Genetics 149(4): 1959–73.
137. Goldmann, W., M. Baylis, C. Chihota, E. Stevenson and N. Hunter (2005). “Frequencies of PrP gene haplotypes in British sheep flocks and the implications for breeding programmes.” J Appl Microbiol 98(6): 1294–302.
138. Moum, T., I. Olsaker, P. Hopp, T. Moldal, M. Valheim, T. Moum and S. L. Benestad (2005). “Polymorphisms at codons 141 and 154 in the ovine prion protein gene are associated with scrapie Nor98 cases.” J Gen Virol 86(Pt 1): 231–5.
139. Saunders, G. C. S., Cawthraw, M. S.J., J. Hope and O. Wildl (2006). “PrP genotype of atypical scrapie cases in Great Britain.” in press.