RESUMO
In this study, we describe two novel adenoviruses isolated from (i) a common lizard (Zootoca vivipara) found dead and examined post-mortem and (ii) pooled samples from free-living sand lizards (Lacerta agilis agilis). Sequencing indicated the two were closely related atadenovirus strains which were distinct from previously recorded adenoviruses in lizards. Adenoviruses are not always associated with disease in squamates, but morbidity and mortality have been reported. These are the first known cases of adenovirus infection in free-living native British lizards, and further monitoring will be necessary to elucidate the implications of these possible pathogens for vulnerable populations of native reptiles.
Assuntos
Lagartos , Adenoviridae , AnimaisRESUMO
We provide an overview of terrestrial animal translocations carried out for conservation purposes in Britain, summarising what has been achieved in recent decades and discussing the issues raised by this approach to conservation. In the last 40 years, at least nine species have been reintroduced following extinction in Britain (or at least one country within Britain), including five birds, one mammal, one amphibian and two invertebrates. Many more species have been translocated within Britain to establish additional populations in order to improve conservation status. We discuss the guidelines and protocols used to assess translocation projects in Britain, notably the IUCN guidelines, most recently revised in 2013. We also discuss the likely use of species translocations in future and suggest that, in our increasingly fragmented landscapes, they will have an important role to play in conservation restoration, especially for animals with limited mobility. Moving species around is a complex undertaking and our understanding of the inherent risks involved, including the risks from disease, has improved significantly in recent years. Conservation translocations should be considered in the context of species recovery targets and high standards should be maintained so that disease risks and other potentially negative impacts are minimised.
Assuntos
Animais Selvagens , Conservação dos Recursos Naturais , Anfíbios , Animais , Aves , Reino UnidoRESUMO
Transmissible spongiform encephalopathies (TSEs) are slow and progressive neurodegenerative diseases of humans and animals. The major target organ for all TSEs is the brain but some TSE agents are associated with prior accumulation within the peripheral lymphoid system. Many studies have examined the effects of scrapie infection on the expression of central nervous system (CNS) genes, but this study examines the progression of scrapie pathology in the peripheral lymphoid system and how scrapie infection affects the transcriptome of the lymph nodes and spleen. Infection of sheep with SSBP/1 scrapie resulted in PrP(Sc) deposition in the draining prescapular lymph node (PSLN) by 25 days post infection (dpi) in VRQ/VRQ genotype sheep and 75 dpi in tonsils and spleen. Progression of PrP(Sc) deposition in VRQ/ARR animals was 25 dpi later in the PSLN and 250 dpi later in spleen. Microarray analysis of 75 dpi tissues from VRQ/VRQ sheep identified 52 genes in PSLN and 37 genes in spleen cells that showed significant difference (P ≤ 0.05) between scrapie-infected and mock-infected animals. Transcriptional pathway analysis highlighted immunological disease, cell death and neurological disease as the biological pathways associated with scrapie pathogenesis in the peripheral lymphoid system. PrP(Sc) accumulation of lymphoid tissue resulted in the repression of genes linked to inflammation and oxidative stress, and the up-regulation of genes related to apoptosis.
Assuntos
Perfilação da Expressão Gênica/veterinária , Regulação da Expressão Gênica , Tecido Linfoide/metabolismo , Tecido Linfoide/patologia , Scrapie/genética , Scrapie/patologia , Animais , Redes Reguladoras de Genes/genética , Genes/genética , Genótipo , Humanos , Linfonodos/metabolismo , Linfonodos/patologia , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Proteínas PrPSc/genética , Scrapie/metabolismo , Ovinos/genética , Baço/metabolismo , Baço/patologia , TranscriptomaRESUMO
Rodent scrapie models have been exploited to define the molecular basis for the progression of neuropathological changes in TSE diseases. We aim to assess whether CNS gene expression changes consistently observed in mouse models are of generic relevance, for example to natural TSE diseases, or are TSE strain, host species or brain region specific. Six genes, representing distinct physiological pathways and showing consistent changes in expression levels with disease progression in murine scrapie models were analysed for expression (RT-qPCR) in defined regions of the sheep brain at various times after SSBP/1 scrapie infection. Gene expression was examined in relation to the development of neuropathological changes including PrP(Sc) deposition and vacuolation. Peripheral infection of sheep with SSBP/1 showed consistent progression of neuropathology as assessed by the temporal course of PrP(Sc) deposition and neuropil vacuolation. The first region affected was the medulla (obex), then the thalamus and finally the cerebellum and frontal cortex. In contrast to mouse scrapie, there were few significant changes in transcript expression for any of the six genes and no consistent changes in patterns of expression in relation to brain region, time after infection or neuropathology in sheep SSBP/1. Gene expression changes in mouse TSE models, even changes consistent with the neuropathology, cannot necessarily be extrapolated to species in which disease naturally occurs. This may represent differences in pathological processes of different scrapie strains or across species; and highlights the difficulties in identifying generic molecular pathways associated to the pathogenesis of TSE disease.