mBeRFP, a versatile fluorescent tool to enhance multichannel live imaging and its applications

Cell and developmental biology increasingly require live imaging of protein dynamics in cells, tissues or living organisms. Thanks to the discovery and the development of a panel of fluorescent proteins over the last decades, live imaging has become a powerful and commonly used approach. However, multicolor live imaging remains challenging. The generation of long Stokes shift red fluorescent proteins, such as mBeRFP, offers interesting new perspectives to bypass this limitation. Here, we constructed a set of mBeRFP-expressing vectors and provided a detailed characterization of this fluorescent protein for in vivo live imaging and its applications in Drosophila. Briefly, we showed that a single illumination source is sufficient to simultaneously stimulate mBeRFP and GFP. We demonstrated that mBeRFP can be easily combined with classical green and red fluorescent protein without any crosstalk. We also showed that the low photobleaching of mBeRFP is suitable for live imaging, and that this protein can be used for quantitative applications such as FRAP or laser ablation. Finally, we believe that this fluorescent protein, with the set of new possibilities it offers, constitutes an important tool for cell, developmental and mechano biologists in their current research.