SEARCH VEGSOURCE:

 

 

Follow Ups | Post Followup | Back to Discussion Board | VegSource
See spam or
inappropriate posts?
Please let us know.
  




From: TSS (216-119-144-1.ipset24.wt.net)
Subject: Neuronal accumulation of abnormal prion protein in sheep carrying a scrapie-resistant genotype (PrPARR/ARR)
Date: August 9, 2004 at 8:32 am PST

-------- Original Message --------
Subject: Neuronal accumulation of abnormal prion protein in sheep carrying a scrapie-resistant genotype (PrPARR/ARR)
Date: Mon, 09 Aug 2004 10:23:24 -0500
From: "Terry S. Singeltary Sr."
To: Bovine Spongiform Encephalopathy
CC: cjdvoice@yahoogroups.com


Risk of scrapie in British sheep of different prion protein genotype

M. Baylis1, C. Chihota1, E. Stevenson1, W. Goldmann2, A. Smith2, K.
Sivam3, S. Tongue3 and M. B. Gravenor1

1 Institute for Animal Health, Compton Laboratory, Compton, Newbury,
Berkshire RG20 7NN, UK
2 Neuropathogenesis Unit, Institute for Animal Health, West Mains Road,
Edinburgh, UK
3 Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, UK

Correspondence
M. Baylis
matthew.baylis@bbsrc.ac.uk

There is a well-established association between sheep prion protein
(PrP) genotype and the risk of death from scrapie. Certain genotypes are
clearly associated with susceptibility to the disease and others to
resistance. However, there have been no attempts to quantify the disease
risk for all 15 PrP genotypes. Here, datasets of the PrP genotypes of
nearly 14 000 British sheep and of more than 1500 confirmed scrapie
cases were combined to yield an estimate of scrapie risk (reported cases
per annum per million sheep of the genotype, or RCAM) for British sheep.
The greatest scrapie risk by far, ranging from 225 to 545 RCAM, was for
the VRQ-encoding genotypes ARQ/VRQ, ARH/VRQ and VRQ/VRQ. The next
greatest risk (37 RCAM) was for the ARQ/ARQ genotype. The ARR/ARR
genotype was the only numerically significant genotype for which no
scrapie cases have been reported. The AHQ allele conferred resistance
and the risk of scrapie in AHQ/VRQ sheep was very low (0·7 RCAM),
although there was a higher and moderate risk for the AHQ homozygote (5
RCAM). The ARH allele appeared to confer susceptibility when encoded
with VRQ, but possible resistance when encoded with other alleles.
Scrapie risk varied with age: for VRQ/VRQ and ARH/VRQ the risk peaked at
2 years of age; that for ARQ/VRQ peaked at 3 years. There was some
evidence that, following the lower risk at 4 and 5 years, a second rise
occurred from about 6 years. Comparison with other published data
indicated that the scrapie risk of certain PrP genotypes may differ
between Great Britain and other countries.

http://vir.sgmjournals.org/cgi/content/abstract/85/9/2735?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=prion&searchid=1092064098354_845&stored_search=&FIRSTINDEX=0&volume=85&issue=9&search_url=http%3A%2F%2Fvir.sgmjournals.org%2Fcgi%2Fsearch

> The ARR/ARR genotype was the only numerically significant genotype for
> which no scrapie cases have been reported.


J Gen Virol 85 (2004), 2727-2733; DOI 10.1099/vir.0.79997-0


Neuronal accumulation of abnormal prion protein in sheep carrying a
scrapie-resistant genotype (PrPARR/ARR)

Anne Buschmann1, Gesine Lühken2, Julia Schultz1, G. Erhardt2 and Martin
H. Groschup1

1 Federal Research Centre for Virus Diseases of Animals, Institute for
Novel and Emerging Infectious Diseases, Boddenblick 5a, 17493 Greifswald
– Insel Riems, Germany
2 Department of Animal Breeding and Genetics, Justus-Liebig-University
Gießen, Ludwigstraße 21B, 35390 Gießen, Germany

Correspondence
Martin H. Groschup
martin.groschup@rie.bfav.de

The susceptibility of sheep to scrapie infection is influenced by prion
gene alleles, which are modulated by polymorphic variations
corresponding to amino acid positions 136, 154 and 173 of the prion
protein (PrP). As no unquestioned report of a diseased sheep carrying
homozygous alleles encoding alanine, arginine and arginine (PrPARR) at
these sites has been published to date, sheep of this genotype are
believed to be scrapie resistant. After the introduction of large-scale
rapid testing for scrapie, a number of so-called ‘atypical’ scrapie
cases have been found in Germany and elsewhere. Among those cases were
two supposedly scrapie-resistant sheep. Brain samples from these animals
tested positive for abnormal PrP (PrPSc) in one of four rapid tests
available. Moreover, scrapie-associated fibril (SAF)-immunoblotting and
immunohistochemistry, which are the generally accepted diagnostic
techniques for scrapie, revealed prominent PrPSc deposition in the
cerebellum. SAF immunoblotting also revealed PrPSc deposition in the
obex, frontal cortex and brainstem. Transmission experiments to
investigate the infectivity of scrapie propagated from these sheep have
been initiated.

http://vir.sgmjournals.org/cgi/content/abstract/85/9/2727?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=prion&searchid=1092064098354_845&stored_search=&FIRSTINDEX=0&volume=85&issue=9&search_url=http%3A%2F%2Fvir.sgmjournals.org%2Fcgi%2Fsearch

TSS






Follow Ups:

  • adipex Harry Juna 2/04/05 (0)
  • adipex Harry Juna 2/04/05 (0)
  • hoodia Harry Juna 2/03/05 (0)


Post a Followup

Name:
E-mail: (optional)
Subject:

Comments:

Optional Link URL:
Link Title:
Optional Image URL: