Yongxin Zhao’s unique scientific contributions
I have developed several enabling tools for optical imaging of biological systems, which are under two main themes: 1. Optogenetic indicators for neuronal activities; 2. Expansion Pathology, a novel imaging strategy for super-resolution imaging of archived clinical samples. For theme 1, I worked on optogenetic indicators for Ca2+ and voltage, two of the most significant types in neuroscience. I tackled the well-known challenge of engineering these protein tools, using novel molecular evolution approaches. Specifically, for Ca2+ indicators, I devised a high-throughput E. coli colony-based screen, in which E. coli cells was programmed to export mutants of Ca2+ indicators into the periplasm. Due to the permeability of the outer membrane of E. coli, periplasmic Ca2+ concentration can be manipulated externally, which in turn …show more content…
In combination with semi-rational designs, we evolved the then-state-of-the-art Ca2+ indicators GCaMP3, and developed a palette of optogenetic Ca2+ indicators with different colors, including the first red-shifted Ca2+ indicator for deeper tissue Ca2+ imaging1. For voltage indicators, I devised a hierarchical approach for molecular evolution of the recently emerged Arch-based voltage indicators, which led to faster and brighter versions, denoted QuasAr2. In parallel, we utilized the principle of fluorescent resonance energy transfer (FRET) and developed a palette bright eFRET voltage indicators using the donor fluorescence of various fluorescent proteins, rather than the acceptor fluorescence of dim Arch indicator, as readout of membrane potential3. To date, the aforementioned optogenetic indicators have been distributed to and used by hundreds of research labs worldwide. For theme 2, I have developed a transformative imaging tool, called Expansion Pathology (ExPath), which enables nanoscale imaging of paraffin-embedded, hematoxylin and
I have developed several enabling tools for optical imaging of biological systems, which are under two main themes: 1. Optogenetic indicators for neuronal activities; 2. Expansion Pathology, a novel imaging strategy for super-resolution imaging of archived clinical samples. For theme 1, I worked on optogenetic indicators for Ca2+ and voltage, two of the most significant types in neuroscience. I tackled the well-known challenge of engineering these protein tools, using novel molecular evolution approaches. Specifically, for Ca2+ indicators, I devised a high-throughput E. coli colony-based screen, in which E. coli cells was programmed to export mutants of Ca2+ indicators into the periplasm. Due to the permeability of the outer membrane of E. coli, periplasmic Ca2+ concentration can be manipulated externally, which in turn …show more content…
In combination with semi-rational designs, we evolved the then-state-of-the-art Ca2+ indicators GCaMP3, and developed a palette of optogenetic Ca2+ indicators with different colors, including the first red-shifted Ca2+ indicator for deeper tissue Ca2+ imaging1. For voltage indicators, I devised a hierarchical approach for molecular evolution of the recently emerged Arch-based voltage indicators, which led to faster and brighter versions, denoted QuasAr2. In parallel, we utilized the principle of fluorescent resonance energy transfer (FRET) and developed a palette bright eFRET voltage indicators using the donor fluorescence of various fluorescent proteins, rather than the acceptor fluorescence of dim Arch indicator, as readout of membrane potential3. To date, the aforementioned optogenetic indicators have been distributed to and used by hundreds of research labs worldwide. For theme 2, I have developed a transformative imaging tool, called Expansion Pathology (ExPath), which enables nanoscale imaging of paraffin-embedded, hematoxylin and