Multifaceted Regulation of Translational Readthrough by RNA Replication Elements in a Tombusvirus

Translational readthrough of stop codons by ribosomes is a recoding event used by a variety of viruses, including plus-strand RNA tombusviruses. Translation of the viral RNA-dependent RNA polymerase (RdRp) in tombusviruses is mediated using this strategy and we have investigated this process using a variety of in vitro and in vivo approaches. Our results indicate that readthrough generating the RdRp requires a novel long-range RNA-RNA interaction, spanning a distance of ∼3.5 kb, which occurs between a large RNA stem-loop located 3'-proximal to the stop codon and an RNA replication structure termed RIV at the 3'-end of the viral genome. Interestingly, this long-distance RNA-RNA interaction is modulated by mutually-exclusive RNA structures in RIV that represent a type of RNA switch. Moreover, a different long-range RNA-RNA interaction that was previously shown to be necessary for viral RNA replicase assembly was also required for efficient readthrough production of the RdRp. Accordingly, multiple replication-associated RNA elements are involved in modulating the readthrough event in tombusviruses and we propose an integrated mechanistic model to describe how this regulatory network could be advantageous by (i) providing a quality control system for culling truncated viral genomes at an early stage in the replication process, (ii) mediating cis-preferential replication of viral genomes, and (iii) coordinating translational readthrough of the RdRp with viral genome replication. Based on comparative sequence analysis and experimental data, basic elements of this regulatory model extend to other members of Tombusviridae, as well as to viruses outside of this family

The Strategies and Effectiveness of Conservation NGOs in the Global Voluntary Standards: The Case of the Roundtable on Sustainable Palm Oil

International audienceConservation nongovernmental organisations (NGOs) and firms have been promoting global voluntary standards, such as the Roundtable on Sustainable Palm Oil (RSPO), to produce environmentally responsible goods in tropical countries. This research seeks to understand the strategies and the effectiveness of conservation NGOs with respect to the RSPO. The authors' research documents that the conservation NGOs, when engaging with the RSPO, may be divided into four categories based on the type of resources mobilised and the conservation goals: (1) 'Collaborative' ones seek to change the system from within by providing scientific research-based information, by holding strategic positions and by creating rules; (2) 'Opponent' ones remain outside the RSPO while using it as a platform for public campaigns; (3) 'Opportunistic' ones focus on conserving geographical areas by adopting either collaborative or opponent strategies to reach their goals; and (4) 'Sceptic' ones support communities to secure local land rights. Such NGOs have implemented strategies that strengthened RSPO's institution. Nevertheless, the institutionalisation of the RSPO prevents the NGOs from reaching their goals for three reasons: (1) individual NGOs cannot change a strategy; (2) NGOs using different engagement strategies are unable to collaborate; and (3) the sceptic NGOs are structurally excluded from the RSPO, though local land rights are a fundamental matter of concern for biodiversity conservation. The NGOs would be more effective in reaching their goals either by focussing on their initial conservation objectives or by strategically collaborating with each other outside the structure of the RSPO