Microscopy

Dr Bruno Martins

I am a post-doctoral researcher in James Locke's group at the Sainsbury laboratory. I am interested in how cells discriminate between different environmental states, integrate dynamic outputs from different gene circuits, and make decisions. In my current research, I use a combination of theory and time-lapse microscopy experiments to understand the dynamical coupling of the cyanobacterial circadian clock to other networks, in both endogenous and synthetic systems.

Circadian clocks are a class of networks that regulate rhythmic expression in response to daily cycles of sunlight. A large fraction of all genes in the cyanobacterium Synechococcus elongatus are clearly under circadian control. Recently, I studied the coupling of the clock to a circuit that controls expression of the gene psbAI. Genes regulated by the clock typically peak once a day, either at dawn or at dusk. However, under conditions of constant low light, I observed a doubling of the frequency of expression of psbAI, i.e., its expression peaks twice a day. Using genetic and environmental perturbations, I found these dynamics can be modulated: either single-peak or two-peak expression can be generated. Using an iteration of modelling and experiments, I then determined the network design principles underlying the dynamics of frequency doubling.

In electronics, clock signals are essential elements of complex circuits, allowing different components of the circuit to be linked and synchronised. In biology, clocks likely play a similar role. Rational designing of oscillators has been a pursuit of synthetic biology since its inception, but evolution has already endowed natural systems with extremely reliable and robust oscillators in the form of circadian clocks. If we can understand how to harness clocks to generate specific (non-circadian) frequencies, and how to systematically integrate clocks with other pathways, we could gain a powerful tool to enable the construction of more complex synthetic circuits.

Before coming to Cambridge, I did a PhD in Peter Swain's lab at the University of Edinburgh. In my PhD I used mathematical modelling to gain insight into two simple, yet ubiquitous, sensing and transductions mechanisms: allosteric sensing and phosphorylation-dephosphorylation cycles. I studied the input-output dynamics of these mechanisms in terms of the fundamental constraints inherent in their design.

Dr Lukas Müller

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I’m interested in the circadian clock and its effect on physiological and agricultural performance in plants. In the OpenPlant project I am investigating the circadian clock in Marchantia polymorpha and analyze the regulation of clock behavior and outputs in this relative of early land plants. In particular, I am focusing on the primary metabolism as an excellent proxy for systemic processes and vegetative growth.

I apply fluorescent imaging tools with computational time-lapse analysis to obtain cell-specific read-outs for the whole plant in real-time. This data is intended to set the stage for both physiological engineering and systems biology approaches.

Part of my project is to engineer fluorescent proteins that are standardised and improved reporters for dynamic changes in gene expression.

Ms Marta Tomaselli

I did my bachelor and master in Biotechnology in Pisa, where I discovered how fascinating plants can be. In the past, I have worked with CRISPR/Cas9 system in two different plant models: Arabidopsis thaliana and Marchantia polymorpha. These were my first experiences related to synthetic biology and they, really, got me involved into it.

In September 2016 I started as an OpenPlant PhD student at the University of Cambridge. In my first year I will do three lab rotations before beginning my final PhD project. During my first rotation in the Haseloff Lab, I have been developing microscopy techniques to image M. polymorpha gemmae. These tools will allow to retain the signal coming from fluorescent proteins in fixed samples and exploit them to achieve a 3D representation of the plant tissue.

For my second rotation, I moved to a different topic, working in the Schornack lab. This project focuses on plant-pathogen interactions: we are looking for pathogen-responsive promoters in M. polymorpha. These sequences can be exploited to generate new reporter lines.

In the future, I would like to continue working with Marchantia and exploit this plant as a model to implement new synthetic circuits. I think that the OpenPlant Community is a great resource for a PhD student, since a lot of different topics are covered by senior researchers to whom you can ask questions and suggestions about your own project.

Dr Susana Sauret-Gueto

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Dr. Susana Sauret-Gueto is an experienced molecular biologist and microscopist, with a scientific background in plant growth and development.

In the OpenPlant Cambridge laboratory, she coordinates the establishment of semiautomated workflows to accelerate the generation and characterisation of genetically engineered Marchantia lines. This requires standardised practices for DNA parts building, as well as appropriate registries to facilitate sharing of resources (DNA parts and transformed plants). Susana is establishing a new facility for robotic liquid-handling around the Echo acoustic liquid handler, and an advanced microscopy facility. The microscopy hub includes a Keyence digital microscope for real-time 3D reconstruction of Marchantia plants, as well as a series of fluorescent microscopes with different resolution capabilities, for example a Leica stereo microscope with fluorescence as well as a Leica SP8 confocal microscope.

The projects being developed along these workflows aim at mapping cell and tissue types throughout Marchantia gemmae development, for basic research questions and synthetic biology approaches. The strategies include the identification of cell types by screening Enhancer Trap lines, a collection of proximal promoters from transcription factors and its screening for specific expression patterns, a high-throughput targeted mutagenesis pipeline using CRISPR/Cas9, and the induction of localised genetic modifications through sector analysis. Susana helps managing and coordinating these interlinked projects working closely with Linda Silvestri, lab Research Technician in charge of Marchantia tissue culture, as well as with the Marchantia team of PhD and postdoc members of the lab. She is specially interested in the sector analysis project in order to dissect gene function and autonomy at the cell and tissue level.

Susana is also the main organiser of the ROC Group (Researchers with OpenPlant Cambridge), which brings together researchers in Cambridge doing Plant Synthetic Biology, both from CU and SLCU, to share common scientific interests, resources and protocols. Researchers work in a variety of plant species, but there are two core subgroups Algae-ROC and Marchantia-ROC. People are very engaged and active, which is making a difference in order to advance projects and pipelines in an efficient and collaborative way.

Dr Thomas Meany

I am jointly hosted by the labs of Lisa Hall (Chemical Engineering and Biotechnology) and Jim Haseloff (Plant Science) as an interdisciplinary fellow part funded through OpenPlant. My background training is as a physicist, with a specific emphasis on optics and microfabrication. I undertook a PhD in Macquarie University (Sydney, Australia) where I developed microphotonic circuits using a 3D laser printing technique. My postdoctoral research continued in Toshiba’s Cambridge Research Labs where I worked on advanced manufacturing techniques for semiconductor quantum dots.

As a part of OpenPlant I am passionate about using optical analytical tools to study the production of secondary metabolites in specialised plant tissues. Specifically, the oil bodies of the Liverwort, Marchantia polymorpha, are potentially rich reservoirs of bio-active compounds. Using Raman microscopy, a label-free, non-destructive spectroscopy technique it is possible to study metabolic processes in real-time. As this is non-destructive it can be performed in situ and therefore both spatial and temporal information can be obtained. My hope is to correlate this data with information available using other approaches such as Matrix Assisted Laser Deposition Ionisation Mass Spectroscopy (MALDI), Gas Chromatography Mass Spectrometry (GC-MS), fluorescence microscopy and other high resolution analytical approaches. In future this could be then adapted to studies of transgenic plant species as an additional tool to study metabolic pathways. Additional model species can also be explored, for instance Nicotiana benthamiana, and potentially crop plants. I am keen to engage with teams operating in the area of natural product chemistry, metabolic engineering or teams focused on alternative analytical approaches.

Photo: Prototype microfluidic rapid 3D printed circuit fabricated during the Bio-Hackathon.

Photo: Prototype microfluidic rapid 3D printed circuit fabricated during the Bio-Hackathon.

Working with the Cambridge University Technology and Enterprise club (CUTEC), I organised the UK’s first Bio-Hackathon, hosted in the Department of Plant Science (Cambridge) during the week of 21-25 June 2016. This was possible with thanks, in part, to a grant provided by the University of Cambridge Synthetic Biology Strategic Research Initiative. This event brought together a diverse interdisciplinary group of 50 participants from across the UK and the world. Teams focused on “bioware” by incorporating hardware, software and wet lab tools. One team developed a 3D printed microfluidic prototyping tool, another built a comparison software tool for DNA synthesis pricing. The winning team built a tool called “Alpha-Brick” which is a drag and drop tool for assembling bio-bricks and plugs directly into Transcriptic (a cloud laboratory) allowing immediate order of an assembled part.