M2 intersnhip available in GustaBrain and PMB teams

• Center for Taste and Feeding Behavior (CSGA), Taste & Brain (GustaBrain) team, Dijon. 
• UMR Food and Microbiological Processes (PAM), Microbiological and Biotechnological Processes (PMB) team, Dijon.

In nature, the fruit fly (Drosophila melanogaster) lives in environments rich in microorganisms, particularly yeasts and filamentous fungi that grow on decaying fruit. These fungi play an ambivalent role, acting both as sources of essential nutrients (sugars, amino acids, lipids) and as potential pathogens that produce toxins. While the fruit fly uses its taste and olfactory systems to assess the quality of these resources before ingestion, the fate of these microorganisms within the digestive tract remains a key stage in host-microbe interaction. This project is part of the broader FungiTasty program, which aims to decipher the sensory and neural mechanisms of fungal perception.

The main objective of this internship is to study in detail the fate of the yeast Saccharomyces cerevisiae (Sc) in the digestive tract of Drosophila, examining both its intestinal transit and its ability to colonize and persist. The intern will be responsible for the following: 
• Comparing fungal physiological states: Monitoring in vivo transit and colonization of the digestive tract using two physiological states of the yeast: spores and the vegetative form. 
• Evaluating digestive transit dynamics: determining the progression, retention, and elimination of yeast as it passes through the different regions of the digestive tract. 
• Monitor development: Observe changes in transit and colonization during the insect’s various developmental stages. 
• Assess physiological impact: Determine how the fungus’s state influences its persistence and localization within the host

To carry out this research, the student will employ a multidisciplinary approach combining microbiology and bioimaging: 
• Fluorescent mutant strains (PAM & CSGA): Development and use of Saccharomyces cerevisiae strains made fluorescent by introducing a GFP gene into their genome. 
• Advanced imaging (PAM & CSGA): Characterization of colonization using imaging techniques to spatially localize the yeast in the intestine. 
• Quantification by cytometry (PAM & CSGA): Use of flow cytometry to rigorously quantify the yeast load present in the intestine.

Ce travail permettra de mieux comprendre les interactions dynamiques entre la drosophile et son microbiote fongique dominant, en distinguant les processus de transit digestif, de rétention et de colonisation intestinale En établissant un lien entre l'état physiologique de la levure et sa capacité de colonisation, ces résultats fourniront des données fondamentales sur la plasticité sensorielle et digestive de la drosophile face aux changements environnementaux. À terme, ces connaissances pourraient avoir des retombées en agriculture, notamment pour le développement de stratégies de lutte biologique basées sur l'utilisation de métabolites ou de micro-organismes.

Étudiant en Master 2 de Microbiologie, Biologie Cellulaire ou Bio-ingénierie, ayant un intérêt pour les interactions hôte-microbe et les techniques d'imagerie.