Structural colors of insect wing scales: from materi-omic characterizations to CRISPR investigations Application deadline: 11 April 2024 We offer a fully-funded 3-year PhD position starting in the fall (1 October 2025) co-financed by ANR and the Centre-Val de Loire Doctoral School (SSBCV) and jointly supervised by Vinodkumar SARANATHAN and Sylvain PINCEBOURDE at the Research Institute for Insect Biology (IRBI, UMR 7261, CNRS / University of Tours). The successful candidate will work in a dynamic, interdisciplinary, and international research environment interacting with world=92s leading experts on biological photonics and biomimetics to the physical ecology of insects. The university strives to be an equal opportunity employer and encourages diversity. Tours is a vibrant modern city situated in heart of the UNESCO World Heritage Loire Valley, the cradle of French Renaissance, and connected by very good public transportation (buses, trams and direct high-speed trains connections: 1h to Paris). HOW WOULD YOU LIKE TO STUDY IRIDESCENT BUGS? How complex traits such as animal coloration and patterning evolve and function is a fundamental question in biology. Many lepidopteran species serve as exemplary model systems in this field due to their simplicity and elegance. While significant progress has been made in understanding the cellular and molecular basis of lepidopteran pigment coloration, however, we have poor knowledge of the mechanisms underlying structural colors produced by photonic nanostructures within iridescent wing scales[1-4] that are often used in social and sexual communication. The PhD project will combine mechanistic, developmental and evolutionary investigations into the functional morphology of iridescent wing scale nanostructures across butterfly species in a comparative fashion. Specifically, the candidate will 1) use materi-omic approaches to create a spatio-temporally resolved map of structure-function relationships of biopolymers and membranes to understand the layer-by-layer construction of butterfly wing scale cell nanostructures during development, 2) and test the functions of key structural motifs identified and the associated genes using CRISPR. The biomimetic expertise gained from this project is in high demand and transferable to industry for sustainable manufacture. WHO ARE WE LOOKING FOR? A scholar with a Master's degree in biology or an equivalent (obtained by Aug. 2025) and (1) a background in molecular biology (broadly defined), evo-devo, organismal biology or a related field; (2) who is scientifically curious, creative, highly-motivated, willing to learn new skills, and able to work independently; (3) with excellent communication (English and French - language courses are provided by the University for foreign scholars) and inter-personal skills; (4) prior experience in raising insects in captivity and proficiency in programming would be advantageous, but not required. Applications submitted via ADUM are due by 11 April 2025 ( https://collegedoctoral-cvl.fr/as/ed/voirproposition.pl?site=CDCVL&matricule_prop=62591) and should include a complete CV with names and full contact details of 2-3 professional referees, a cover/motivation letter, and all transcripts (Bachelor=92s and Master=92s or equivalent). For informal enquiries, please write to SARANATHAN@univ-tours.fr. Online interviews will take place during the week of 14 April. Candidates shortlisted after this step will have final interviews at the doctoral school (on-site or online by request) on 21 May. References: [1] Saranathan, V. et al. 2010. Structure, function, and self-assembly of single network gyroid (I4(1)32) photonic crystals in butterfly wing scales. PNAS 107, 11676-11681; [2] Saranathan, V. et al. 2015. Structural Diversity of Arthropod Biophotonic Nanostructures Spans Amphiphilic Phase-Space. Nano Lett. 15, 3735-42; [3] Prakash, A. et al. 2022. Antennapedia and optix regulate metallic silver wing scale development and cell shape in Bicyclus anynana butterflies. Cell Reports 40, 111052; [4] Seah, K. S. and Saranathan, V. 2023. Hierarchical morphogenesis of swallowtail butterfly wing scale nanostructures. eLife 12, 89092. Vinod Kumar Saranathan (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)