Low phototoxicity live imaging of cells and their molecular machineries at high temporal and spatial resolution.

Our overall aim is to enable the study of the dynamic cellular and molecular processes which underpin the formation and repair of animal tissues. The cell is the fundamental unit of all complex life forms and so understanding the biology of the cell and its component parts is a key goal in life science and medical research. While we currently benefit from several imaging systems which allow us to image living cells as they interact within tissues, most of these imaging methods are phototoxic - they make use of high-power light source to visualise cellular machineries. This phototoxicity limits our ability to image live cells, as it introduces artefacts and can even lead to cell death. Next-generation microscopes such as the Zeiss AiryScan 980 confocal, are profoundly changing the way cells, sub-cellular structures and tissues can be studied in a live environment, by enabling imaging of cells at low phototoxicity and in very high detail. This type of capability is essential in any world-leading research institution. Equipped with this new imaging system, our consortium of researchers will be able to study how cells interact and communicate through chemical and mechanical signals to generate the various tissues that make up our organs. UCL has invested significantly in the past seven years in developing a globally recognised Centre of Excellence with a strategic Science Technology Platform, by ensuring it has cutting edge imaging equipment to support it research community.

The research supported with this proposal will include work in epithelial tissues, which line most of our organs (e.g. lung, kidney, intestine), nervous system development and maintenance of their internal functions, as well as work on the pathways which control cell fate commitment, morphogenesis (cell-shape) and migration. Collectively, these processes underpin the formation of our tissues and organs and allow for their repair upon injury or disease. Studying these fundamental developmental processes and identifying key players controlling these pathways will help further human knowledge of understanding health and disease.

The overarching objective of this application is to establish the fundamental principle and pathways which underpin the ability of cells to interact in order to generate and repair the tissues that make up our organs. Collectively, cell differentiation, morphogenesis and movement underpin tissue architecture, function and repair. These processes are controlled by molecular machineries, which are intrinsic to cells and can be subjected to external regulation, allowing for cells to coordinate their actions. Studying these processes requires imaging of cells in vivo as they interact to form or repair tissues. Most imaging methods, and especially those enabling high spatial resolution, tend to also be phototoxic and lead to artefacts and even cell death. With this application, we seek to address this limitation by acquiring an additional Zeiss Airyscan 2, 980 confocal microscope, with 8Y multiplexing on an inverted microscope stand. This new imaging system will allow us to image cells and their machineries in vivo, at high spatial resolution and with minimum phototoxicity. We already know this imaging modality is a game changer at UCL for a wide range of research projects, across many research disciplines, such as; cell and developmental biology, neuroscience, infection and immunity and physiological sciences. However, some researcher's progress is being restricted by the lack of availability of our two existing Airyscan 980's as demand is so high. In addition, our two Airyscan 980's have quite different capabilities/uses, in that one has multiphoton laser on an upright stand, whilst the other is single photon on an inverted stand, meaning users are restricted on which system they should use based on their sample/s. Typical waiting times are more than two weeks and often longer. We have already limited access to our two systems by ensuring each user wanting to use the Airyscan, actually requires super-resolution for their research.