Tramier Group Research

Directly connected to imaging facilities MRic-photonics and in close collaboration with biologists of Rennes, the team “Microscopy for cell biosensing” aims at developing techniques and methodologies in fluorescence microscopy to study dynamics of protein-protein interactions and biochemical activities in live sample. Our approach is mainly driven by methodological and technological development, its transfer and its applicability in biology to answer relevant new questions.

Fluorescence based methods encompass different disciplines and a vast number of technical approaches. Advances in different photonic imaging techniques and the development of fluorescent probes, and particularly fluorescent proteins, have raised fluorescence microscopy to the level of dominance in the field of biology. 
The work of the team is clearly positioned as a link between advanced microscopy developments and issues carried by the cell biology. In that context, our main research interested and expertise are focused on FRET by FLIM and fluorescence anisotropy and on two color FCS applied to spatio-temporal studies of protein-protein interactions and the development of biosensors for biochemical activities. 

The project is built following three axes: 

1- Technological development in fluorescence microscopy such as fastFLIM (Fluorescence Lifetime Imaging Microscopy) prototype or IR temporal focusing for PALM (Photo Activation Localization Microscopy)

fastFLIM prototype developed by the team and transfered to MRic imaging facilities - © Marc TRAMIER / IGDR

2- Methodological development using fluorescence microscopy such as multiplex FRET by FLIM to follow several biosensors simultaneously or dual color FLCS to follow protein interactions without spectral bleed through artifact

Single wavelength excitation and dual color FLIM for multiplexing genetically encoded FRET biosensors

3- Biological applications of fluorescence original methods such as spatiotemporal regulation of kinase activity or cadherin tension measurements during epithelial cell division. 

Tension Sensor module using FRET measurements in live Xenopus embryo to characterize spatio-temporal dynamics of molecular forces through Cadherin - © Marc TRAMIER / IGDR

The objective is double: the transfer of these methodologies to imaging facility MRic (IBiSA Plateform) and eventually to valorize the development by industrial transfer, and the use of these approaches in collaboration with other teams which would lead to new results of high quality in cellular and developmental biology.