Timothée Lionnet

  • Assistant Professor of Cell Biology and Biomedical Engineering

  • Institute for Systems Genetics (NYU School of Medicine)



I am a biophysicist who develops novel imaging technologies to understand the fundamental principles of gene expression.

During my PhD with Vincent Croquette at the Ecole Normale Supérieure (Paris, France), I designed and built a highly sensitive single-molecule magnetic tweezers microscope. This system allowed me to discover that the DNA double helix stretches when overwound, a counterintuitive property bearing profound consequences for DNA sequence recognition. I also uncovered new principles driving the mechanochemistry of DNA helicases. I then joined the laboratory of Rob Singer (A. Einstein College of Medicine, New York) in order to continue developing single molecule technologies, this time inside cells and animals. These include a mouse line in which individual mRNA molecules of an endogenous gene can be detected by fluorescence, as well as a biosensor reporting on the translational state of single mRNAs in live cells and animals. I then became the Project Scientist for the Transcription Imaging Consortium (TIC) at the H.H.M.I. Janelia Research Campus. In this position, I led a Janelia-based research group that developed fluorescence technologies to understand the rules that govern transcription at the single molecule level.

I joined the Institute for Systems Genetics at NYU School of Medicine in 2017, where we develop cutting-edge microscopy approaches to visualize and manipulate single cells in real time. We use these unique tools to understand how robust cell fates emerge from random dynamics at the molecular level, and how those processes are disrupted during cancer evolution. 

Research Interests
Single-cell Biology, Gene Expression, Spatial Transcriptomics, Systems Microscopy, Single-molecule imaging, Image Analysis, Deep-Learning, Optogenetics