During the first year of the project, we successfully accomplished the objectives set in two milestones: i) Milestone M1, at month M3, concerning the setup of dissemination channels (website, social media, etc.), the definition of the experimental methods, as well as of the plans for data management and dissemination/exploitation activities; ii) Milestone M2 at month 12, concerning the completion of the first set of experiments on the engineering of synthetic circuits for aggregation and swarming, the building of the environment for experimentation with real/virtual gradients, and the development of the first version of the ethics framework. In the following, I provide further details of the scientific work related to Milestone M2, and I will briefly illustrate the work on those Tasks (i.e. T1.2 T1.3 T2.2 T3.1 T3.2 and T4.2) that started in the first year of the project and will be reported in the following reporting periods.
As far as it concerning synthetic circuit engineering, we have developed a pheromone-based aggregation behaviour in young hermaphrodites C. elegans. Hermaphrodites secrete sex pheromones to increase male attraction when they run out of sperm. We have express, through genetic engineering the receptor for sex-pheromone in hermaphrodites in order to make them attracted one to the other, and thus to induce aggregation and eventually swarming. The results of preliminary experiments illustrated in Deliverable D1 (D1.1) show that genetically-engineered hermaphrodites showed clear attraction from adult+4 days.
We have also started the exploration of a second approach for inducing swarming behaviour in C. elegans based on touch information. C. elegans sense gentle touch to the body via a set of touch receptor neurons (TRNs). We have coupled touch sensation and dwelling, such that worms encountering repeated touch by multiple other individuals tend to dwell, driving collective aggregation. Preliminary results are illustrated in Deliverable D1 (D1.1). Our work on the synthetic engineering of circuits for aggregation and swarming in C. elegans will continue in the next months. This work is expected to be completed at month M21 contributing to Milestone M3.
During the first year, we have completed the construction of the apparatus for experimentation with real/virtual gradients. In order to unravel how C. elegans collectives navigate and potentially share information to reach a target location we have generate a robust, repeatable and controlled environment that allow us to challenge the animals with versatile sensory experiences and accurately quantify their behaviour in these environments. We have built an odour chamber to generate controlled realistic
odour environments by integrating the odour chamber with a custom tracking microscope to image animals navigating within the chamber, allowing us to bridge the gap between individual and collective navigation. This work is detailed in Deliverable 4 (D2.1) and D5 (D2.2). This apparatus will be used to carry out the work of the other Tasks in work-package WP2.
We have also developed the first part of the Ethics Framework, which discusses issues related to potential harms to genetically modified C. elegans as living beings, and expected benefits from the use the BABots technology. The ethics framework part I is illustrated in deliverable D10 (D4.1). This framework will be expanded in the next months of the project with the analysis of other aspects related to the ethicality of BABots, as well as with data concerning the perception and evaluation of the BABots technology by different types of potential stakeholders and by the general public.
As mentioned above, apart from those Tasks whose activity has been already documented with deliverables submitted at month M12, other Tasks have started in this first year of the BABOTS project. In Task 1.3 the experimental work focuses on the design of mechanism, within the AWC chemosensory neuron, enabling switching between a sequence of behaviours. In Task 2.2 several experiments have been already run to study how variations in oxygen concentration as well as the combined presence of attraction and repulsion pheromones affect the spatial distribution of C. elegans and their locomotion. In Task 3.1 the initial data generated form Task 2.2 has been used to develop data driven models of aggregation and swarming behaviour in C. elegans. In Task 3.2 computer-based simulation models have been developed to analysis the roles of heterogeneity of behaviour in supporting aggregation and self-organized leadership. Preliminary work has also been done for Task 4.2 by taking an auxotrophic approach. This means that we established a dependency of C. elegans on an external, synthetic compound for its development and propagation.
