Rundschau

Ohne ZusammenfassungPflanzenschutzorganisation für Europa und die Mittelmeerländer     

Informationen aus der EWG [EG] (V)

Ohne Zusammenfassung7737 Bad Dürrheim, Königsberge Straße 35     

A framework for understanding the potential for emerging diseases in aquaculture

Numerous diseases have emerged as serious economic or ecological problems in aquaculture species. The combination of factors behind the emergence of each disease is unique, but various common factors are apparent. We combine risk-analysis methods and virulence theory with historical examples (mainly from salmonid production) to identify key disease-emergence risk factors. Diseases have emerged through pathogen exchange with wild populations, evolution from non-pathogenic micro-organisms and anthropogenic transfer of stocks. Aquacultural practices frequently result in high population densities and other stresses (such as intercurrent disease) which increase the risk of infection establishment and spread. As aquaculture expands and new species are farmed, diseases will continue to emerge and affect both wild and farmed fish adversely. The rate and extent of emergence can be reduced by the application of biosecurity programmes designed to mitigate the risk factors for disease emergence.     

Darwinian medicine: applications of evolutionary biology for veterinarians

Every medical phenomenon has both a mechanistic explanation and an evolutionary explanation. Veterinarians are accustomed to dealing with the mechanistic, the "what" or the "how", of various disease conditions, and applying treatment accordingly. Darwinian medicine is a field that addresses the evolutionary explanation, the "why" for various medical conditions. This review focuses on these Darwinian explanations and is divided into 4 main categories--host defenses, virulence, genetic conflict, and incomplete adaptation to a changing environment. Each of these areas is reviewed, with examples of evolutionary reasons for disease conditions. Consideration of adaptationist reasons for many of these disease phenomena should make veterinarians better clinicians, educators, and researchers.     

Modulating sphingolipid biosynthetic pathway rescues photoreceptor degeneration

Mutations in proteins of the Drosophila phototransduction cascade, a prototypic guanine nucleotide-binding protein-coupled receptor signaling system, lead to retinal degeneration and have been used as models to understand human degenerative disorders. Here, modulating the sphingolipid biosynthetic pathway rescued retinal degeneration in Drosophila mutants. Targeted expression of Drosophila neutral ceramidase rescued retinal degeneration in arrestin and phospholipase C mutants. Decreasing flux through the de novo sphingolipid biosynthetic pathway also suppressed degeneration in these mutants. Both genetic backgrounds modulated the endocytic machinery because they suppressed defects in a dynamin mutant. Suppression of degeneration in arrestin mutant flies expressing ceramidase correlated with a decrease in ceramide levels. Thus, enzymes of sphingolipid metabolism may be suitable targets in the therapeutic management of retinal degeneration.