Global Ecology and Conservation (Dec 2021)
Ecological vulnerability analysis for suppression of Drosophila suzukii by gene drives
Abstract
Synthetic gene drives are transgenic constructs that aim to bias heredity and thereby influence the characteristics and fate of populations regarding abundance and evolution. Aside from irreversible effects in ecosystems that could be triggered by the release of a gene drive, research on confinable drives or even the reversibility of gene drives is underway and shows first success under laboratory conditions. However, their effectiveness under realistic conditions is not entirely clear unless first test releases have taken place. Since a potentially irreversible intervention into ecosystems is created, a prospective assessment is needed. We present an approach of prospective ecological vulnerability analysis for the proposed control of the invasive pest Drosophila suzukii by using gene drives. The analysis considers the accidental spread of the gene drive to the native habitat of Drosophila suzukii, with a focus on Japan. It contains a mapping of potential impacts as a consequence of the suppression of the insect. Multiple cascading effects were identified including the potential spread of the gene drive in geographic range or potential hybridization with non-target species. Determining the vulnerability of an ecosystem requires information regarding specific characteristics at different organizational levels. The vulnerability analysis of an affected ecosystem will initially serve to identify gaps in knowledge. Reducing complexity and breaking down the potential events that might arise from a gene drive population suppression enables to better understand endpoints i.e. concrete effects. Three potential effects have been selected for a specific analysis of the vulnerability of populations and species. A high vulnerability was obtained for the suppression of non-target (native) populations of Drosophila suzukii as well as for a decrease in specialized parasitoid abundance. The paper proposes the outline of a comprehensive prospective approach to understand the susceptibility of an ecosystem to unintended and irreversible harm.
