The Generation of Tools and Development of Methods for Live Imaging Mouse Embryos & Stem Cells

Live imaging nucleus and membrane in mouse embryonic stem (ES) cells.

Central to our studies is a need for observing events as they take place in their native environment. We want to define and quantify the stereotypical and dynamic behaviors of cells present in wild-type context, and contrast these findings with those occurring in mutants and experimentally perturbed conditions. Our long term goal is to bridge the gap between molecular signaling and the physical changes that are the final effectors of morphogenesis. Optical imaging is an integral component of the approach we are taking to achieve this goal.

We continue to develop improved genetically-encoded reporters for use in mouse embryos and stem cells. We have generated strains of mice that provide readouts of cell position (e.g. by labeling the nucleus) and cell morphology (e.g. by labeling the plasma membrane) permitting the generation of 4-dimensional (3D time-lapse) data at a resolution equivalent to routine histology on fixed specimens. We have developed some of the first photomodulatable reporter expressing mouse strains and stem cell lines, as well as several single-cell resolution cell signaling reporters (e.g. for Wnt and Notch signaling). These reagents provide a powerfull toolbox offering the potential to follow and quantify biological processes in embryos and tissues at high resolution.

A single-cell resolution Wnt signaling (pink) reporter live imaged in a mouse embryo.