La tentation génétique
vendredi 6 avril 2018 -
La menace des espèces envahissantes non seulement sur la biodiversité mais sur la viabilité de nos agricultures, les conséquences sur l’environnement des stratégies classiques d’éradication, l’efficacité très relative des solutions alternatives traditionnelles Bio, donnent toute leur importance aux réflexions et expérimentations en cours basées sur la génétique. Mais, comme toutes les stratégies de lutte contre les parasites, les lecteurs de gènes ne sont pas sans danger. Les difficultés impliquées dans le confinement des lecteurs de gènes peuvent limiter l’utilisation et exiger des accords internationaux avant la libération des types approuvés. évaluation des risques écologiques des lecteurs de gènes destinés à lutter contre les ravageurs agricoles doit être effectué avant leur déploiement.
Source : Gene Drives April 5, 2018 by IAPPS
Gene Drives : The New Tool for Pest Control ?
In 2014, biological engineer Kevin Esvelt proposed a novel technique for genetically altering entire populations of problem species in the wild called gene drives. The implications of this methodology would be to genetically modify agricultural pests and invasive species so to almost entirely eradicate populations ; with even potential uses for combating zoonotic disease spread such as malaria.
Gene drives are self-propagating genetic devices which contain genetic modifications. The concept is based on the idea of genetically modifying a set number of individuals of a given species, for example with genes resulting in infertility and releasing them into the wild. Within a few reproductive generations, the majority of the wild population would be infertile.
Although the hypothetical use of a genetic interaction process such as gene drives for pest control has been seriously considered for over a decade, its implementation was not straightforward. New gene-editing developments have changed this. Although there haven’t been any releases of gene drives yet, it may be a matter of time before several agricultural pests and natural enemies become potential candidates for carrying gene drives.
In the current climate, fall armyworm (Spodoptera frugiperda) would be an ideal target for study in this field. As fall armyworm is currently one of Sub-Saharan Africa’s most invasive species, with it rapidly spreading across the continent since 2016 into over 10 countries. This insect feeds on over 80 plant species, including major agricultural crops such as maize, sugarcane and rice ; with the larval stages being able to consume entire plants and devastate fields. Therefore, the potential to implement gene drives to hinder one of the developmental stages or render the insect infertile would provide a major release to the agricultural sector across Africa.
In terms of the bioethics of gene drives, the mutated animal isn’t injured or killed as a direct result of the gene drive, therefore it would be a more humane method of reducing the pest species population. Genetically induced mutations are passed from parent to offspring, only the target species would be affected, which isn’t the case with the use of traps, poisons and chemical treatments.
It is important to consider that current pest control practices are also not risk-free.