Structural and Functional Studies On Ancestral

**Structural and functional studies on ancestral olfactory genes in Spodoptera littoralis**:

- Réf **ABG-125689**
- Stage master 2 / Ingénieur- Durée 6 mois- Salaire net mensuel Selon la loi en vigueur au moment du stage- 05/09/2024- INRAE- Lieu de travail- Versailles Ile-de-France France- Champs scientifiques- Agronomie, agroalimentaire
- Mots clés- olfaction, insects, molecular biology-
- 30/09/2024**Établissement recruteur**:

- Le département ECOSENS rassemble, sur un objet modèle commun, un ensemble unique d’approches et de savoir-faire complémentaires, alliant bioinformatique, génomique fonctionnelle, génétique moléculaire, biochimie, physico-chimie, neuroanatomie, imagerie, électrophysiologie, éthologie et modélisation, autorisant les approches du gène au champ, du neurone au modèle biophysique, de l’individu aux populations. Enfin, l’utilisation de modèles ravageurs des cultures nous permet d’avoir un équilibre entre recherche fondamentale et appliquée, en proposant des solutions pour la lutte contre les insectes ravageurs. L’équipe CREA se focalise sur les étapes en amont de la chimioréception (signaux, réception et dégradation).- Le Centre de recherche de Versailles-Grignon est l’un des 17 centres régionaux de INRAE. Les unités qui le composent produisent connaissances et savoir-faire dans les domaines de la biologie des plantes, de l’agriculture et de l’écologie, de l’alimentation et des aliments. Le centre est accessible facilement par bus depuis les principales gares de Versailles. Un hébergement sur le centre est possible pendant la durée du stage.**Description**:

- Perception of chemical signals is essential for an organism to avoid dangers, identify food sources, or find a mate. It also plays a preponderant role in the evolution of species through their involvement in adaptation to a new ecological niche or reproductive isolation. In insects, in particular, chemical senses are essential in mate recognition through pheromone recognition and also in host plant choice.- In insects, the reception of chemical clues is mediated by a multimeric receptor that consists of two types of subunits: an olfactory receptor (OR) that accommodates the odorant molecule and the highly conserved olfactory receptor co-receptor (Orco). Each insect evolved its own repertoire of OR to meet its own need to navigate its environment. The evolution of the OR gene family follows a classical birth-death model of gene evolution, marked by high rates of gene duplications. However, how duplicated ORs acquire distinct response spectra following duplication remains unknown. In the frame of the ANR project AncestOR and the present internship, we will used an approach of ancestral gene resurrection to reconstruct the evolutionary trajectory that led each receptor to acquire its own response spectra following duplication. We will use an integrative approach combining bioinformatics (ancestral gene reconstruction, 3D modeling, molecular docking), electrophysiological experiments to assess the tuning breadth of ancestral receptors, and site-directed mutagenesis to pinpoint crucial amino acids for functional shift between duplicated genes.**Profil**:
We are looking for a highly motivated student interested in evolution, structural and functional analyses and with prior experience with molecular biology work. The student will need to be fluent in English. The internship will have to imperatively start in January 2025 and will be paid according to French law.

**Prise de fonction**:

- 01/01/2025