First Detection of Tobacco Mosaic Virus in Tobacco Fields in Northern Lebanon.

BACKGROUND: Tobacco mosaic virus (TMV) is the most known virus in the plant mosaic virus family and is able to infect a wide range of crops, in particular, tobacco, causing a production loss. OBJECTIVES: Herein, and for the first time in Lebanon, we investigated the presence of TMV infection in crops by analyzing 88 samples of tobacco, tomato, cucumber and pepper collected from different regions in North Lebanon. METHODS: Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), revealed a potential TMV infection of four tobacco samples out of 88 crop samples collected. However, no tomato, cucumber and pepper samples were infected. The TMV+ tobacco samples were then extensively analyzed by RT-PCR to detect viral RNA using different primers covering all the viral genome. RESULTS AND DISCUSSION: PCR results confirmed those of DAS-ELISA showing TMV infection of four tobacco samples collected from three crop fields of North Lebanon. In only one of four TMV+ samples, we were able to amplify almost all the regions of viral genome, suggesting possible mutations in the virus genome or an infection with a new, not yet identified, TMV strain. CONCLUSION: Our study is the first in Lebanon, revealing TMV infection in crop fields and highlighting the danger that may affect the future of agriculture.

Purkinje-cell degeneration in prion protein-deficient mice is associated with a cerebellum-specific Doppel protein species signature.

PrP(c) (cellular prion protein) and Doppel are antagonizing proteins, respectively neuroprotective and neurotoxic. Evidence for Doppel neurotoxicity came from PrP(c)-deficient (Prnp(0/0)) mouse lines developing late onset Purkinje-cell degeneration caused by Doppel overexpression in brain. To address the molecular underpinnings of this cell-type specificity, we generated Doppel N-terminal-specific antibodies and started to examine the spatio-temporal expression of Doppel protein species in Ngsk Prnp(0/0) brain. Although Doppel overexpression is ubiquitous, Western analyses of normal and deglycosylated protein extracts revealed cerebellar patterns distinct from the rest of the brain, supporting the idea that neurotoxicity might be linked to a particular Doppel species pattern. Furthermore, our newly raised antibodies allowed the first Doppel immunohistochemical analyses in brain, showing a distribution in Prnp(0/0) cerebellum similar to PrP(c) in wild type.