Projects Offered

1 PhD project offered in the IPP summer call Molecular Mechanisms in Genome Stability & Gene Regulation

Scientific Background

Odorant Receptors (ORs) constitute the main family of chemosensory genes in nearly all species. Based on the canonical model of the olfactory circuit, a single OR is expressed in each Olfactory Receptor Neuron (ORN), which projects to a single OR-specific glomerulus in the brain. ORs are fast evolving gene families that underwent frequent expansions and contractions to facilitate adaptation to different ecological needs and the evolution of insect societies. This poses a fundamental challenge to the evolution of olfactory neural circuits, which should occur in parallel to that of OR gene families to maintain the canonical ‘OR-ORN-glomerulus’ scheme. Recent studies on ants and mosquitoes suggest that this canonical model might not be universal. 

By combining brain anatomical and transcriptome analyses, we have shown that workers of the ant Temnothorax longispinosus exhibit large variation in the number of glomeruli in their antennal lobes, despite expressing almost all OR genes in their antennae. Together with previous studies, this suggests the existence of different mechanisms for the development of the olfactory system in ants and adds possible variants of neural circuit architecture found for olfaction across insect taxa. 

 Our goal is to understand the organizational logic of the olfactory system of T. longispinosus from genes to neurons by linking OR genomic organization and expression patterns. Our approach combines genomic, molecular, neurobiological, comparative, and computational methods to link genome architecture to neural circuit organization and to understand the functional consequences and evolutionary origin of the diversity of olfactory circuit organization.

PhD Project: Evolution and regulation of odorant receptor expression in ants

The student will be part of a new interdisciplinary effort that includes Carlotta Martelli (neurobiology and computational biology), Hugo Darras (evolution and genomics), and Susanne Foitzik (behavior and evolution), and two PhD students. This position will focus on bioinformatics applied to genomic, single-cell transcriptomic, and neurobiological data, and will be co-supervised by H. Darras and C. Martelli. The ideal candidate should have a strong background in bioinformatics, with practical or theoretical experience in single-cell transcriptomics and comparative genomics. A keen interest in neurobiology is essential. Additional skills in evolutionary biology, insect handling, and programming (preferably in Python) would be advantageous, but are not mandatory.

If you are interested in this project, please select Martelli as your group preference in the IPP application platform.

Publications relevant to this project

Züfle, P., Batista L. Brandão L, D’Uva G., Daniel C., Martelli C. (2025) Impact of developmental temperature on neural growth, connectivity, and function. Sci Adv 11, eadp9587. Link

Darras H, Berney C, Hasin S, Drescher J, Feldhaar H, Keller L. (2023) Obligate chimerism in male yellow crazy ants.Science, 380 (6640), 55-58 Link

Caminer, M. A., Libbrecht, R., Majoe, M., Ho, D. V., Baumann, P., & Foitzik, S. (2023). Task-specific odorant receptor expression in worker antennae indicates that sensory filters regulate division of labor in ants.Communications Biology 2023 6:1, 6(1), 1–12. Link

A relevant review on the general topic:

Duan, Q., & Volkan, P. C. (2020). Ant Olfaction: Smells Like an Insect, Develops Like a Mammal. Current Biology, 30(16), R950–R952. Link