Xenobiotics control in insect Legs

• Applicant: Privatdozent Dr. Matthias Behr
• Subject Area: Animal Physiology and Biochemistry ; General Genetics and Functional Genome Biology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 530093972

The tarsa at the end of the insect legs are the contact and uptake site of xenobiotics including plant secondary metabolites and insecticides. The following project is based on our yet-unnoted hypothesis that the tarsa control xenobiotic uptake and metabolism. The tarsus is a cuticular tube equipped with sensory cells to taste the substratum, and with setae required for adhesion. These structures and their function have been well studied to date; by contrast, our understanding of the tarsal cuticle and the underlying epidermal cells is limited. Here, we address the problem of tarsa as a key organ of xenobiotic processing using the fruit flies Drosophila melanogaster (non-pest) and D. suzukii (pest) as model insects. We will analyse the histology of tarsa by transmission and scanning electron microscopy to learn about the cuticle and the epidermis. By proteomics and transcriptomics, we will identify proteins and genes present in the tarsa. In a pilot experiment, we have been able to isolate 25 cytochrome P450s and 19 glutathione S-transferases involved in xenobiotic detoxification and 11 cuticle proteins in the tarsa of D. melanogaster. This experiment will be repeated with D. suzukii tarsa. Candidate proteins will be tagged with fluorescence by gene editing (CRISPR/Cas9) to monitor their expression and localisation behaviour during exposure to contact insecticides such as cyhalothrin. Again, applying gene editing protocols, mutant versions of the respective genes will be generated to study their role in insecticide detoxification. Finally, the ability of these enzymes to metabolise insecticides will be evaluated in vitro. The results of this project will constitute crucial information to the fundamental question of how the insect tarsa are used in contact with the proximal environment of the animal body during orientation in its ecological niche and will allow us to formulate smart strategies in controlling insect pests by manipulating this interactive process.

• DFG Programme: Research Grants
• International Connection: France
• Cooperation Partners: Dr. Gaelle Le Goff; Privatdozent Dr. Bernard Moussian