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Full-Text Articles in Medicine and Health Sciences
Blood Chimerism Confounds Genetic Relative Susceptibility Testing For Classical Scrapie In Sheep, David A. Schneider, Ahmed Tibary, Terje Taudsepp, Pranab J. Das, Katherine I. O'Rourke
Blood Chimerism Confounds Genetic Relative Susceptibility Testing For Classical Scrapie In Sheep, David A. Schneider, Ahmed Tibary, Terje Taudsepp, Pranab J. Das, Katherine I. O'Rourke
Other Publications in Zoonotics and Wildlife Disease
Classical scrapie disease is a transmissible spongiform encephalopathy of sheep that is enzootic in the United States. Susceptibility of sheep to classical scrapie is linked to single nucleotide polymorphisms in the prion protein gene (PRNP), forming the basis for genetic testing strategies used by national efforts to eradicate scrapie. Such efforts are occasionally hampered by inconclusive results stemming from the detection of ‘‘complex’’ genotypes. Naturally occurring cases of ovine chimerism are thought to account for some of these instances. In the current report, 4 naturally occurring ovine chimeras are documented through cytogenetic and molecular analyses. All 4 of these sheep …
Nor98 Scrapie Identified In The United States, Christie M. Loiacono, Bruce V. Thomsen, S. Mark Hall, Matti Kiupel, Diane Sutton, Katherine I. O'Rourke, Bradd Barr, Lucy Anthenill, Delwyn Keane
Nor98 Scrapie Identified In The United States, Christie M. Loiacono, Bruce V. Thomsen, S. Mark Hall, Matti Kiupel, Diane Sutton, Katherine I. O'Rourke, Bradd Barr, Lucy Anthenill, Delwyn Keane
Other Publications in Zoonotics and Wildlife Disease
A distinct strain of scrapie identified in sheep of Norway in 1998 has since been identified in numerous countries throughout Europe. The disease is known as Nor98 or Nor98-like scrapie, among other names. Distinctions between classic scrapie and Nor98 scrapie are made based on histopathology and immunodiagnostic results. There are also differences in the epidemiology, typical signalment, and likelihood of clinical signs being observed. In addition, sheep that have genotypes associated with resistance to classic scrapie are not spared from Nor98 disease. The various differences between classic and Nor98 scrapie have been consistently reported in the vast majority of cases …
Development Of An Assay To Determine Single Nucleotide Polymorphisms In The Prion Gene For The Genetic Diagnosis Of Relative Susceptibility To Classical Scrapie In Sheep, Mary Lynn Johnson, Jessica M. Evoniuk, Charles L. Stoltenow, Katherine I. O'Rourke, Dale A. Redmer
Development Of An Assay To Determine Single Nucleotide Polymorphisms In The Prion Gene For The Genetic Diagnosis Of Relative Susceptibility To Classical Scrapie In Sheep, Mary Lynn Johnson, Jessica M. Evoniuk, Charles L. Stoltenow, Katherine I. O'Rourke, Dale A. Redmer
Other Publications in Zoonotics and Wildlife Disease
The objective of this study was to develop a reliable Taqman® 5' Nuclease Assay for genotyping sheep for scrapie susceptibility. The sheep prion gene contains 2 single nucleotide polymorphisms (SNPs) that may mediate resistance to classical scrapie, one at codon 136, alanine (A) or valine (V), and another at codon 171, arginine (R) or glutamine (Q). The R allele appears to confer resistance to classical scrapie, with the AA136 RR171 genotype the most resistant to scrapie and QR171 only rarely infected in the US sheep population. The Assays by DesignSM protocol was used for development of …
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, B. M. Alexander, R. H. Stobart, W. C. Russell, Katherine I. O'Rourke, G. S. Lewis, J. R. Logan, J. V. Duncan, G. E. Moss
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, B. M. Alexander, R. H. Stobart, W. C. Russell, Katherine I. O'Rourke, G. S. Lewis, J. R. Logan, J. V. Duncan, G. E. Moss
Other Publications in Zoonotics and Wildlife Disease
Scrapie is one of several transmissible spongiform encephalopathies of livestock. Disease susceptibility is linked to polymorphisms in the normal prion protein gene that encodes the mammalian prion precursor. Codon 171 of this gene is a major determinant of scrapie susceptibility. Selection for arginine (R) at codon 171 is encouraged by the USDA to decrease the incidence of scrapie. Objectives of this study were to determine the frequency of R allele variants at codon 171 in a sample of sheep from five breeds (Columbia, Hampshire, Rambouillet, Suffolk, and Targhee) and western white-faced commercial ewes and to determine whether the R allele …