Postdoctoral Researcher in Cellular Biophysics (M/F)

Job Description

Missions

The Role of Heterogeneities in Phase Transitions of Self-Organized Embryonic Systems Gastrulation is a crucial stage of embryonic development, during which an initially homogeneous tissue organizes into distinct cellular layers.
Our team recently demonstrated that this transition involves mechanochemical dynamics in gastruloids, in vitro models derived from embryonic stem cells (Hashmi et al., eLife 2022; Gsell & Tlili et al., Nature Physics 2025). However, the mechanisms by which local heterogeneities emerge and influence differentiation and collective behaviors remain poorly understood. This project aims to elucidate how these heterogeneities regulate mesodermal differentiation and epithelial-mesenchymal transitions (EMT) using innovative experimental approaches.
Objectives 1. Create controlled heterogeneities in gastruloids via fusion experiments and the spatiotemporal activation of TBRA (Brachyury), a key transcription factor in mesodermal differentiation and primitive streak formation during gastrulation.
2. Characterize the impact of these heterogeneities on EMT transitions and collective behaviors.
3. Identify critical thresholds (number, location, and synchronization of cells) in these mechanisms

Activity

1. Creation of controlled heterogeneities • Fusion experiments: Combining gastruloids at different stages of differentiation to study the impact of heterogeneities on EMT transitions and collective behaviors. • Spatiotemporal activation of TBRA: Use of optogenetic systems to activate TBRA in specific cellular subpopulations.
2. Characterization of phase transitions • Analysis of EMT and mesodermal markers: Immunofluorescence to track key markers (TBRA, Snail, Mesp1, E-cadherin, N-cadherin). • Mechanical analysis of tissues in collaboration with biophysicists from the team
3. Development and optimization of protocols • Generation of transgenic lines • Establishment of optogenetic systems: development and validation of an Opto-TBRA system for its controlled activation.
4. Analysis of collective behaviors • Real-time imaging: Use of confocal and multiphoton microscopy • Data analysis: use of image analysis tools.

Your Profil

Skills

• Background in biology with a strong quantitative focus • Experience working with embryonic stem cells: culture and differentiation of mESCs and/or hESCs.
• Advanced imaging techniques: confocal microscopy, immunofluorescence.
• Molecular biology techniques: cloning
• Experience in data analysis (Fiji, Python, etc.)

Your Work Environment

The IBMD, located on the Luminy Campus, comprises approximately 220 permanent staff members—including researchers, faculty members, engineers, and technicians—as well as temporary staff on fixed-term contracts, postdocs, doctoral students, and interns, distributed across 21 research teams and 11 technical platforms and services. The IBDM is a joint research unit under the supervision of the CNRS and AMU, which explores the field of developmental biology and associated pathologies. The work will be carried out within the “Physical Approaches to Cell Dynamics and Tissue Morphogenesis” team. As the laboratory is composed of members of various nationalities, fluency in English is essential. The postdoctoral researcher will work in a multidisciplinary environment (Physics, Biology, Engineering).

Compensation and benefits

Compensation

From €3,132.82 to €4,343.20 gross per month

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions