Genetically encoded actin filament organization reporters for live cells and tissues
Essential physiological functions, including cell division, cell adhesion and motility, and tissue morphogenesis, rely on the capacity of animal cells to change and adapt their shape. To accomplish these force-dependent tasks, animal cells make use of actin cytoskeletal filaments. The precise way in which actin filaments organize, i.e. how actin filaments are physically oriented in space, and how filament organization is remodeled in time, is determinant for force generation. Being able to measure actin filament organization directly in living cells and tissues thus promises to advance our understanding of how proteins and signaling pathways individually and collectively control actin-driven cellular functions. We will present the development of novel genetically-encoded, green- and red-fluorescent-protein-based reporters that allow non-invasive, quantitative measurements of actin filament organization in living cells and tissues by using polarization-resolved fluorescence microscopy. We will show examples of actin organization measurements in living mammalian cells in culture, as well as in living Drosophila and C.elegans embryos, and fission yeast cells.