We have created tools and established protocols for the imaging of fixed and inert, live Sulfolobus cells using super-resolution and conventional microscopy. These, along with optimised synchronization methods and FACS assays, have helped us construct a complete, high-resolution timeline of the Sulfolobus cell cycle. This temporal map has nucleated two new projects in the lab, focused on chromosome dynamics, and on ESCRTIII-mediated cell division - both with major implications for our understanding of the evolution of eukaryotic cell cycle control.
We have constructed the first ever live-imaging setup for a thermophilic organism using a custom-built microscope. We have used this to corroborate our data from fixed, staged cells using membrane and DNA dyes stable at high temperature. Building upon this base, we expect to monitor real-time cell cycle dynamics. We also expect that this platform will be easily adapted to the imaging of other extremophilic organisms, many of which are of commercial interest.
Our data on cell cycle dynamics will be used to inform an ongoing genetic screen for new cell cycle regulators. In the meantime, we have used phylogenetic analyses to link our collaborators’ and our findings in Sulfolobus to the newly discovered uncultured Asgard archaea that appear to be the closest known relatives of eukaryotes. We have also identified structural analogies to eukaryotic nuclear remodelling, a process we are currently investigating using fission yeast as a model.
Much of this work has been carried out in close collaboration with the Henriques lab at UCL, the Lindas lab at Stockholm University, and the Ettema lab at Uppsala University. The work has helped the Baum lab and collaborators obtain further funding from the BBSRC and the Wellcome Trust, and we expect the bulk of these results to be published within the year or so.
