INTRASYM: Genetic requirements in Caballeronia insecticola for intracellular symbiosis inside t[...]

Organisation/Company Université Paris-Saclay GS Biosphera - Biologie, Société, Ecologie & Environnement, Ressources, Agriculture & Alimentation Research Field Biological sciences » Biology Researcher Profile Recognised Researcher (R2) Leading Researcher (R4) First Stage Researcher (R1) Established Researcher (R3) Application Deadline 5 May 2026 - 22:00 (UTC) Country France Type of Contract Temporary Job Status Full-time Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Intracellular symbiosis is important in the biology of extant insects and plants, as a major transition in the evolution of life and for biotechnological applications in plants, yeast and fungi. The PhD project is framed within an overall objective that is to disclose and understand the evolutionary innovations enabling intracellular symbiosis in insects and to apply this understanding to engineer, as a proof of concept, an extracellular association (extra-sym) into a new intracellular symbiosis (intra-sym). The motivation for the IntraSym project is our recent discovery that in the stinkbugs (insect infraorder Pentatomomorpha), closely related species have either extracellular bacterial symbionts in the lumen of the gut (extra-sym) or intracellular symbionts of the same bacterial species located inside the gut epithelial cells (intra-sym). Thus, the Pentatomomorpha provides an ideal and unique framework to identify and compare the genetic determinants for extra-sym and intra-sym in both, the insect host and the bacterial gut symbionts. The INTRASYM PhD project will identify the genetic determinants that are specifically or commonly crucial for extra-sym and intra-sym in the model gut symbiont Caballeronia insecticola. C. insecticola establishes an extra-sym in stinkbugs of the Alydidae and Coreidae families and an intra-sym in species of the Rhyparochromidae family. The PhD candidate will use functional genomics (Tn-seq and RNA-seq), comparative genomics and a candidate gene approach to identify the bacterial adaptations needed for symbiosis in different extra-sym and intra-sym hosts belonging to these stinkbug families. Candidate functions enabling C. insecticola to infect gut epithelial cells or chronically establish in them in intra-sym hosts will be further characterized in depth.

• Use functional genomics (Tn‑seq, RNA‑seq)
• Perform comparative genomics and a candidate gene approach
• Identify genetic determinants crucial for extra‑sym and intra‑sym
• Characterise bacterial adaptations needed for symbiosis in different hosts
• Further investigate candidate functions enabling C. insecticola to infect gut epithelial cells or chronically establish in them in intra‑sym hosts

Début de la thèse : 01/10/2026

Funding category: Contrats ED : Programme blanc GS‑BioSphERA

Additional Information

Work Location(s)

Number of offers available 1 Company/Institute Université Paris-Saclay GS Biosphera - Biologie, Société, Ecologie & Environnement, Ressources, Agriculture & Alimentation Country France City Gif-sur-Yvette Geofield