Demonstration of lateral transmission of scrapie between sheep kept under natural conditions using lymphoid tissue biopsy

Ryder, S. J.; Dexter, G.; Bellworthy, S. J.; Tongue, Sue C.

doi:10.1016/j.rvsc.2003.11.007

Cited by 67 publications

(62 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Transmission occurs between scrapie-affected ewes and their lambs [71][72][73] but data strongly indicates that this is predominantly horizontal transmission 74,75 with lambs exposed to the disease analyzed; the cell pellet, casein whey and cream fractions from both colostrum and milk. It was estimated that a milliliter of whole milk could contain prion infectivity equivalent to that found in 6 μg of posterior brain stem from an animal with clinical scrapie.…”

Section: Secretion Of Prions Within Parturient Materialsmentioning

confidence: 99%

Prion transmission

Gough

Maddison

2010

Prion

124

View full text Add to dashboard Cite

Section: Secretion Of Prions Within Parturient Materialsmentioning

confidence: 99%

Prion transmission

Gough

Maddison

2010

Prion

124

View full text Add to dashboard Cite

“…Sc have been detected in the fetal part of the placenta [3,8,13,39,49,51,53,56] which is shed after lambing. Infectivity is thus spread into the environment causing a rather efficient horizontal transmission to other sheep (or goats) with susceptible PrP genotypes.…”

Section: Infectivity and Prpmentioning

confidence: 99%

TSE pathogenesis in cattle and sheep

2008

View full text Add to dashboard Cite

-Many studies have been undertaken in rodents to study the pathogenesis of transmissible spongiform encephalopathies (TSE). Only a few studies have focused on the pathogenesis of bovine spongiform encephalopathy (BSE) and scrapie in their natural hosts. In this review, we summarize the most recent insights into the pathogenesis of BSE and scrapie starting from the initial uptake of TSE agents and crossing of the gut epithelium. Following replication in the gut-associated lymphoid tissues (GALT), TSE agents spread to the enteric nervous system (ENS) of the gut. Infection is then carried through the efferent fibers of the post-ganglionic neurons of the parasympathetic and sympathetic nervous system to the pre-ganglionic neurons in the medulla oblongata of the brain and the thoracic segments of the spinal cord. The differences between the pathogenesis of BSE in cattle and scrapie in sheep are discussed as well as the possible existence of additional pathogenetic routes.

show abstract

“…A transmissão do agente acontece de forma natural, porém o modo de transmissão da doença ainda não é conhecido em todos os detalhes (RYDER et al, 2004). Os sinais clínicos variam conforme a região cerebral afetada e o desenvolvimento é lento e progressivo.…”

Section: Introductionunclassified

Seleção de ovinos geneticamente resistentes ao scrapie

2012

View full text Add to dashboard Cite

A susceptibilidade dos ovinos ao scrapie está relacionada a polimorfismos do gene da proteína priônica celular (PRNP). Polimorfismos nos códons 136 (alanina, A/ valina, V), 154 (arginina, R/ histidina, H) e 171 (glutamina, Q/ arginina, R/ histidina, H) são os principais determinantes de susceptibilidade/resistência ao scrapie clássico. Eles são combinados em 4 principais variantes do alelo ancestral ARQ: VRQ, AHQ, ARH e ARR. Programas de melhoramento genético na União Europeia e Estados Unidos têm utilizado como estratégia selecionar o alelo resistente ARR, diminuindo a frequência do alelo susceptível VRQ em populações de ovinos. No Brasil, há poucos dados de genotipagem do gene PRNP e, até o momento, nenhum tipo de controle baseado em cruzamentos direcionados foi implementado. Esta revisão focará aspectos importantes como epidemiologia e resistência genética, como ferramenta de programas de controle de scrapie. Palavras-chaves:Genotipagem; Ovinos; Polimorfismo; Proteína priônica celular; Scrapie AbstractSelective breeding for scrapie resistance in sheep. It is well known that the susceptibility of sheep to scrapie is determined by the host's prion protein gene (PRNP). PRNP polymorphisms at codons 136 (alanine, A/ valine, V), 154 (histidine, H/arginine, R) and 171 (glutamine, Q/histidine, H/arginine, R) are the main determinants of sheep susceptibility/resistance to classical scrapie. There are four major variants of the wild-type ARQ allele: VRQ, AHQ, ARH and ARR. Breeding programs have been developed in the European Union and the USA to increase the frequency of the resistant ARR allele while decreasing the frequency of the susceptible VRQ allele in sheep populations. In Brazil, little PRNP genotyping data are available for sheep, and thus far, no controlled breeding scheme for scrapie has been implemented. This review will focus on important epidemiological aspects of scrapie and the use of genetic resistance as a tool in breeding programs to control the disease.

show abstract

Demonstration of lateral transmission of scrapie between sheep kept under natural conditions using lymphoid tissue biopsy

Cited by 67 publications

References 18 publications

Prion transmission

Prion transmission

TSE pathogenesis in cattle and sheep

Seleção de ovinos geneticamente resistentes ao scrapie

Contact Info

Product

Resources

About