Cuticular Lipid and Defense Chemistry of Collembola

• Applicant: Professor Dr. Stefan Schulz
• Subject Area: Biological and Biomimetic Chemistry ; Animal Physiology and Biochemistry ; Organic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 504384643

Collembola (springtails), which diverged from insects approximately 450 million years ago, exhibit an unusual chemistry of their constituents that differs from that of insects. One example is the atypical lipids found in the outer lipid layer of their skin, the epicuticle. These lipids are of great importance in arthropods as they play a crucial role in regulating water balance and can also act as chemical signals due to their composition. The project's aim is to investigate their chemistry and biological function, such as their role as chemical signals. While chemically simple hydrocarbons predominate in insects, Collembola display a more complex chemistry with unique compounds, including long-chain terpenes, polymethyl-branched esters, ethers, and other yet-to-be-identified substances. This project will focus on elucidating the structure of these substances, which are often found in limited quantities due to the small size of Collembola, using mass spectrometric and infrared spectroscopic methods and syntheses. Establishing our own cultures will provide improved access to biological material. These cultures will also allow the investigation of biosynthetic pathways not only for the lipids but also for defensive substances, such as alkaloids, alongside the increasingly available genomes of Collembola. Defensive substances and pheromonal signaling compounds will also be examined, as they can be analyzed using the same methods. A key compound for these investigations is the novel diterpene Curviseton, which we have identified. Since it can only be isolated in extremely small amounts, a synthesis will be performed to provide material and determine its absolute configuration. This will help ascertain whether and how Curviseton acts as a signal. A variety of Collembola use defensive substances as a defense mechanism, and these compounds are often known only from springtails. Some alkaloids have already been discovered and will be characterized through synthesis. By studying additional Collembola species, we will obtain a broader understanding of the composition of the epicuticle and the defensive and signaling substances, providing insights into their chemistry evolution. We will be able to assess the extent to which chemical defense strategies are widespread in Collembola and what biosynthetic pathways are employed. To investigate additional species, a network has been established with biologists who can provide material for the planned studies and who can also explore further functions of Collembola substances. This has fundamental implications for understanding the ecology of these small yet vital arthropods for soil health, whose chemistry has been scarcely researched thus far.

• DFG Programme: Research Grants