POSITION: Ph.D. position in the incoming Mutualisms Research Group at the John Innes Centre, Norwich, UK. POSITION DESCRIPTION: Many animals rely on beneficial microbes for nutrition, defence, or reproduction. In this project, the student will explore an exciting new dimension of these relationships: how microbes influence animal behaviour. The study system will be tortoise beetles, which carry an obligate bacterium that digests complex plant material for its host. Our preliminary research shows that beetle larvae without this bacterium behave very differently from their symbiotic relatives, dispersing rather than forming protective feeding groups. This project will investigate how the presence or absence of the symbiont changes larval behaviour, the chemical and nutritional mechanisms behind these changes, and the potential consequences for survival when facing natural predators. The work will combine hypothesis-driven experiments in the laboratory with annual fieldwork in Panama, in collaboration with the Smithsonian Tropical Research Institute, to place these findings in a real-world ecological context. The student will gain a broad skill set, including behavioural tracking, microbial manipulation, chemical analysis (GC-MS), molecular biology, and statistical modelling. They will also receive training in transferable skills such as scientific communication, project management, and public engagement. From the outset, the student will be encouraged to take ownership of the project, shaping experimental design, developing new approaches, and driving the research with increasing independence. By integrating laboratory, analytical, and field-based methods, the student will play an active role in defining the research direction and will have opportunities to present their work at international conferences and engage with a global network of collaborators. This is an opportunity to join an inclusive, collaborative, and internationally connected research environment, working on a conceptually novel project with relevance to ecology, evolution, and sustainable agriculture. The Norwich Research Park Biosciences Doctoral Training Programme (NRPDTP) is offering fully funded studentships for October 2026 entry. The programme offers postgraduates the opportunity to undertake a 4-year PhD research project whilst enhancing professional development and research skills through a comprehensive training programme. You will join a vibrant community of world-leading researchers. All NRPDTP students undertake a three-month professional internship placement (PIPS) during their study. The placement offers exciting and invaluable work experience designed to enhance professional development. Full support and advice will be provided by our Professional Internship team. This project has been shortlisted for funding by the NRPDTP. Shortlisted applicants will be interviewed on 3,4 or 5 February 2026. Visit our website for further information on eligibility and how to apply: https://biodtp.norwichresearchpark.ac.uk/. Our partners value diverse and inclusive work environments that are positive and supportive. Students are selected for admission without regard to gender, marital or civil partnership status, disability, race, nationality, ethnic origin, religion or belief, sexual orientation, age or social background. To maximise accessibility and attract students from underrepresented groups to our programme we have introduced bespoke templates for applicant Personal and Research statements which will enable every applicant to fully represent themselves through providing suitable examples and evidence. These forms are on the NRPDTP website and must be used for these sections of the application form. Entry requirements At least UK equivalence Bachelors (Honours) 2:1. English Language requirement (Faculty of Science equivalent: IELTS 6.5 overall, 6 in each category). Funding Notes This project is awarded with a 4-year Norwich Research Park Biosciences Doctoral Training Partnership PhD DTP studentship. The studentship includes payment of tuition fees (directly to the University), a stipend to cover living expenses, and a Research Training Support Grant for each year of the studentship. For additional information, and to clarify any questions, please contact hassan.salem@jic.ac.uk or visit www.mutualisms.net. RELEVENT REVERENCES García-Lozano, M., Henzler, C., Porras, M.Á.G., Pons, I., Berasategui, A., Lanz, C., Budde, H., Oguchi, K., Matsuura, Y., Pauchet, Y., and Salem, H. (2024). Paleocene origin of a streamlined digestive symbiosis in leaf beetles. Current Biology. 34, 1621-1634.e9. Berasategui, A., Breitenbach, N., García-Lozano, M., Pons, I., Sailer, B., Lanz, C., Rodríguez, V., Hipp, K., Ziemert, N., Windsor, D., and Salem, H. (2022). The leaf beetle Chelymorpha alternans propagates a plant pathogen in exchange for pupal protection. Current Biology. 32, 4114-4127.e6. Pons, I., González Porras, M.Á., Breitenbach, N., Berger, J., Hipp, K., and Salem, H. (2022). For the road: calibrated maternal investment in light of extracellular symbiont transmission. Proceedings of the Royal Society: Biological Sciences. 289, 20220386. García-Lozano, M., and Salem, H. (2025). Microbial bases of herbivory in beetles. Trends in Microbiology. 33, 151-163. Porras, M.Á.G., Pons, I., García-Lozano, M., Jagdale, S., Emmerich, C., Weiss, B., and Salem, H. (2024). Extracellular symbiont colonizes insect during embryo development. ISME Communications. https://doi.org/10.1093/ismeco/ycae005. Dr. Hassan Salem Max Planck Research Group Leader Mutualisms Research Group Max Planck Institute for Biology Tübingen, Germany 72076 Email: hassan.salem@tuebingen.mpg.de Tel.:+49-7071-601-1367 Website: www.mutualisms.net Hassan Salem (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)