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Grunwald N.J.,U.S. Department of Agriculture | Garbelotto M.,University of California at Berkeley | Goss E.M.,University of Florida | Heungens K.,Belgium Institute for Agricultural and Fisheries Research | Prospero S.,Swiss Federal Institute of forest
Trends in Microbiology | Year: 2012

The recently emerged plant pathogen Phytophthora ramorum is responsible for causing the sudden oak death epidemic. This review documents the emergence of P. ramorum based on evolutionary and population genetic analyses. Currently infection by P. ramorum occurs only in Europe and North America and three clonal lineages are distinguished: EU1, NA1 and NA2. Ancient divergence of these lineages supports a scenario in which P. ramorum originated from reproductively isolated populations and underwent at least four global migration events. This recent work sheds new light on mechanisms of emergence of exotic pathogens and provides crucial insights into migration pathways. © 2012.

Charlier J.,Ghent University | van der Voort M.,Ghent University | van der Voort M.,Belgium Institute for Agricultural and Fisheries Research | Kenyon F.,Moredun Research Institute | And 2 more authors.
Trends in Parasitology | Year: 2014

Global agriculture will be required to intensify production from a shrinking natural resource base. Helminth infections of ruminants are a major constraint on efficient livestock production. The current challenge is to develop diagnostic methods that detect the production impact of helminth infections on farms in order to target control measures and contribute to the global challenge of preserving food security. We review here our understanding of the effects of helminth infections and control practices on productivity and the diagnostic tools that can inform on this. By combining advances in helminth laboratory diagnostics and animal health economics, sustainable management of helminth infections can be integrated into the whole-farm economic context. © 2014 Elsevier Ltd.

De Schepper V.,Ghent University | De Swaef T.,Ghent University | De Swaef T.,Belgium Institute for Agricultural and Fisheries Research | Bauweraerts I.,Ghent University | Steppe K.,Ghent University
Journal of Experimental Botany | Year: 2013

It is generally believed that an osmotically generated pressure gradient drives the phloem mass flow. So far, this widely accepted Münch theory has required remarkably few adaptations, but the debate on alternative and additional hypotheses is still ongoing. Recently, a possible shortcoming of the Münch theory has been pointed out, suggesting that the Münch pressure flow is more suitable for herbs than for trees. Estimation of the phloem resistance indicates that a point might be reached in long sieve tubes where the pressure required to drive the Münch flow cannot be generated. Therefore, the relay hypothesis regained belief as it implies that the sieve tubes are shorter then the plant's axial axis. In the source phloem, three different loading strategies exist which probably result from evolutionary advantages. Passive diffusion seems to be the most primitive one, whereas active loading strategies substantially increase the growth potential. Along the transport phloem, a leakage-retrieval mechanism is observed. Appreciable amounts of carbohydrates are lost from the sieve tubes to feed the lateral sinks, while a part of these lost carbohydrates is subsequently reloaded into the sieve tubes. This mechanism is probably involved to buffer short-term irregularities in phloem turgor and gradient. In the long term, the mechanism controls the replenishment and remobilization of lateral stem storage tissues. As phloem of higher plants has multiple functions in plant development, reproduction, signalling, and growth, the fundamental understanding of the mechanisms behind phloem transport should be elucidated to increase our ability to influence plant growth and development. © The Author 2013. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Stals A.,Ghent University | Van Coillie E.,Belgium Institute for Agricultural and Fisheries Research | Uyttendaele M.,Ghent University
Current Opinion in Virology | Year: 2013

Food borne viruses such as norovirus and hepatitis A virus are increasingly recognized worldwide as the most important cause of food borne gastro-intestinal illness. Food borne outbreaks, often involving multiples cases, have been reported and associated with food products of both animal and non-animal origin. Most foods are contaminated with food borne viruses during preparation and service. However, bivalve molluscs and occasionally produce (in particular leafy vegetables and soft red fruits) may be contaminated during production and processing. Owing to the low infectious dose of these viruses, the presence of few viral particles on the food is often sufficient for an infection. Over the past decade, molecular methods-such as RT-(q)PCR-have therefore been developed for rapid detection of viral contamination on foods. The availability of these detection methods has led to an increased detection of viral contamination in foods. However, RT-(q)PCR and other molecular methods detect the mere presence of an RNA (or DNA) fragment and are unable to differentiate between infectious and non-infectious viral particles in the monitoring of food products for viral contamination which makes interpretation of these results not straightforward. The current review aims to summarize recent efforts made for a more correct interpretation of these positive RT-(q)PCR results. First of all, RT-(q)PCR test results should be analyzed taking into account the results of various appropriate controls in place to assure well-functioning of good laboratory practices. Subsequently, approaches that may aid to facilitate acceptation and that may aid to put RT-(q)PCR positive food products into context from a public health perspective are discussed. These approaches include (1) the use of a critical acceptance limit, (2) the confirmation of positive RT-(q)PCR results and (3) the potential correlation with faecal indicators. Finally, the current review provides insights in a selection of methods currently under development that may be able to facilitate the specific detection of infectious food borne viruses. © 2012 Elsevier B.V.

Fiems L.O.,Belgium Institute for Agricultural and Fisheries Research
Animals | Year: 2012

Molecular biology has enabled the identification of the mechanisms whereby inactive myostatin increases skeletal muscle growth in double-muscled (DM) animals. Myostatin is a secreted growth differentiation factor belonging to the transforming growth factor-β superfamily. Mutations make the myostatin gene inactive, resulting in muscle hypertrophy. The relationship between the different characteristics of DM cattle are defined with possible consequences for livestock husbandry. The extremely high carcass yield of DM animals coincides with a reduction in the size of most vital organs. As a consequence, DM animals may be more susceptible to respiratory disease, urolithiasis, lameness, nutritional stress, heat stress and dystocia, resulting in a lower robustness. Their feed intake capacity is reduced, necessitating a diet with a greater nutrient density. The modified myofiber type is responsible for a lower capillary density, and it induces a more glycolytic metabolism. There are associated changes for the living animal and post-mortem metabolism alterations, requiring appropriate slaughter conditions to maintain a high meat quality. Intramuscular fat content is low, and it is characterized by more unsaturated fatty acids, providing healthier meat for the consumer. It may not always be easy to find a balance between the different disciplines underlying the livestock husbandry of DM animals to realize a good performance and health and meat quality. © 2010 by the authors; licensee MDPI, Basel, Switzerland.

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