The development of complex and controversial innovations. Genetically modified mosquitoes for malaria eradication.

When there is significant uncertainty in an innovation project, research literature suggests that strictly sequencing actions and stages may not be an appropriate mode of project management. We use a longitudinal process approach and qualitative system dynamics modelling to study the development of genetically modified (GM) mosquitoes for malaria eradication in an African country. Our data were collected in real time, from early scientific research to deployment of the first prototype mosquitoes in the field. The 'gene drive' technology for modifying the mosquitoes is highly complex and controversial due to risks associated with its characteristics as a living, self-replicating technology. We show that in this case the innovation journey is linear and highly structured, but also embedded within a wider system of adoption that displays emergent behaviour. Although the need to control risks associated with the technology imposes a linearity to the NPD process, there are possibilities for deviation from a more structured sequence of stages. This arises from the effects of feedback loops in the wider system of evidence creation and learning at the population and governance levels, which cumulatively impact on acceptance of the innovation. The NPD and adoption processes are therefore closely intertwined, meaning that the endpoint for R&D and beginning of 'mainstream' adoption and diffusion are unclear. A key challenge for those responsible for NPD and its regulation is to plan for the adoption of the technology while simultaneously conducting its scientific and technical development.

Foot-and-mouth disease virus 2C is a hexameric AAA+ protein with a coordinated ATP hydrolysis mechanism.

Foot-and-mouth disease virus (FMDV), a positive sense, single-stranded RNA virus, causes a highly contagious disease in cloven-hoofed livestock. Like other picornaviruses, FMDV has a conserved 2C protein assigned to the superfamily 3 helicases a group of AAA+ ATPases that has a predicted N-terminal membrane-binding amphipathic helix attached to the main ATPase domain. In infected cells, 2C is involved in the formation of membrane vesicles, where it co-localizes with viral RNA replication complexes, but its precise role in virus replication has not been elucidated. We show here that deletion of the predicted N-terminal amphipathic helix enables overexpression in Escherichia coli of a highly soluble truncated protein, 2C(34-318), that has ATPase and RNA binding activity. ATPase activity was abrogated by point mutations in the Walker A (K116A) and B (D160A) motifs and Motif C (N207A) in the active site. Unliganded 2C(34-318) exhibits concentration-dependent self-association to yield oligomeric forms, the largest of which is tetrameric. Strikingly, in the presence of ATP and RNA, FMDV 2C(34-318) containing the N207A mutation, which binds but does not hydrolyze ATP, was found to oligomerize specifically into hexamers. Visualization of FMDV 2C-ATP-RNA complexes by negative stain electron microscopy revealed hexameric ring structures with 6-fold symmetry that are characteristic of AAA+ ATPases. ATPase assays performed by mixing purified active and inactive 2C(34-318) subunits revealed a coordinated mechanism of ATP hydrolysis. Our results provide new insights into the structure and mechanism of picornavirus 2C proteins that will facilitate new investigations of their roles in infection.