Meet Pavel Baranov, Professor of Biomolecular Informatics at the University College Cork, Ireland. Pavel’s research group focuses on the understanding of how proteins are synthesised and how their synthesis is regulated.
Why did you choose to become a scientist?
When I was a toddler, I wanted to be a firefighter. Within a couple of years, I decided that being an astronaut would be more fun. A few more years passed, and I began to dream of becoming a scientist. I guess at that point I stopped growing and started living my dream.
What is your research focus?
My research group studies RNA translation. Translation is at the core of biology. Cells spend most of their energy on protein synthesis and the ribosome is the most abundant molecular machine in almost all cells. Ribosomal RNAs and tRNAs are the most conserved molecules across all kingdoms of life, and it is now apparent that proteins evolved earlier than DNA. Life as we know it relies on two main type of molecules not found outside of living systems – nucleic acids and proteins. It is the process of translation that connects these two chemistries together. I could hardly think of a more fundamental, interesting and challenging cellular process than translation.
Where do you see this field heading in the future?
As translation brings two chemistries together it is far more complex than other molecular process such as transcription and replication. Because of its complexity and the lack of tools to study it, studying translation is very challenging. The tools are now being developed, e.g. variations of ribosome profiling techniques, real-time single molecule imaging, cryo-EM microscopy, etc. The main change that I foresee is that translation will draw the attention of many more biomedical researchers, for better or worse.
What is your number one tip for people looking for scientific training?
Independent practice is the key in my opinion. After taking a course you may get the impression that you can do something, but it could be a false impression – you don’t really know if you can unless you have done it.
If you weren’t a scientist, what would you be?
Science is not a job for me, it is a dream. If I were not able to make my living as a researcher, I would have to find something else to make earnings, but I would not give up on my scientific interests.
The invention of ribosome profiling is the most significant development in the field of protein synthesis since the deciphering of the ribosome 3D structure. Ribosomal profiling is a popular technique for measuring the rate of translation in addition to measuring RNA levels, but this was somewhat possible even before. The unique ability of ribosome profiling is the detection of which open reading frames are being translated in RNA. The application of ribosome profiling revealed that even in eukaryotes the same mRNA molecule is often used for making more than one polypeptide, and that our current knowledge of the human genome protein coding repertoire is still far from complete. In addition to detecting translated frames, ribosome profiling could be used to detect ribosome pauses. We recently learned that such pauses could be used to regulate gene expression and other biological processes. This course will provide trainees with everything what is needed for mastering this powerful technology, from hands-on experience in generating ribosome profiling data to bioinformatics analysis and the use of public data resources.
The field of biology owes some of its most compelling discoveries to careful visual observation. From Van Leeuwenhoek’s use of new microscopes to describe microscopic “animalcules” in the late 1600s, to Ramon y Cajal’s pioneering 19th century work illustrating beautiful and complex neuronal architecture. Images inspire us, help us generate new hypotheses, and shed light into the tiny worlds yet unexplored. Indeed, these observations uniquely help us understand the structures and dynamics of life, something that would not be achievable with approaches like biochemistry alone.
The images are only as valuable as the amount of information that we can deduce from it.
Generating meaningful images, however, is not an easy task. There have always been limits to what we can observe, due to the properties of the sample or the techniques that we can apply to it. These are the boundaries that microscopists seek to push. A successful imaging experiment requires an amenable sample, a contrast agent to reveal the structures of interest, and a microscope that is capable of capturing an image at a relevant scale. Moreover, the images are only as valuable as the amount of information that we can deduce from it. Therefore, image storage, accessibility and analysis are crucial. Each one of these steps offers opportunities for optimisation and new technologies.
The EMBO | EMBL Symposium “Seeing is Believing: Imaging the Molecular Processes of Life” (9-12 October 2019) presented us with exciting new developments in all of these fields, coupled with a drive to make new progress available as quickly as possible to the community through preprints, open-source initiatives, and resource sharing.
Advances in sample preparation
At the heart of every imaging approach is the sample. Even the best microscope is ineffective with dim or improperly prepared samples. At Seeing is Believing, we saw an emphasis on using expansion of samples to help overcome the resolution limits of microscopy and solve some traditionally difficult problems. In particular, we were impressed with expansion-based approaches to study centriole structure (Paul Guichard, Ultrastructural Expansion Microscopy) and resolve microtubules tightly packed within axons (Lukas C. Kapitein). By far, the biggest emphasis in sample improvement was on the development of new fluorescent probes and biosensors. Kai Johnsson presented design strategies for the improvement of live cell dyes, and introduced new MaP dyes that are SNAP and HALO compatible, and importantly require no wash to clear unbound probe. Periklis Pantazis presented a mechanosensor based on the Piezo1 stretch activated ion channel, allowing users to visualise mechanical stress within a live cell. Atsushi Miyawaki wowed the audience by meeting the challenge to “be better than a firefly” with a new variant of luciferase named AkaBLI, which his lab generated through targeted evolution. This improved luciferase allowed them to visualise neuronal activity within freely behaving mice and marmosets.
Advances in microscopy
The features of our microscopes directly determine which questions we can address. Seeing is Believing highlighted exciting new development in building cutting-edge microscopy tools. Reto Fiolka presented a novel single-objective light-sheet microscope enabling imaging of live cells in microfluidics devices or 3D environments with 200 nm lateral resolution. Kevin Dean complemented novel light-sheet development by presenting an axially swept light-sheet microscope ideally suited for all clearing techniques that provides an unprecedented field of view enabling whole tissue imaging with sub-micron resolution. With her imaging approach, Alexandra Pacureanu surprised the audience with how X-ray holographic nano-tomography is capable of resolving the fine, dense and complex neuronal circuitry in large tissues or even organism providing a new route to understand how the nervous system processes information.
All acquired data is meaningless if we cannot extract information from it. At Seeing is Believing, it became obvious how artificial neuronal networks have become important for image analysis. Applications range from segmentation to denoising an image (BGnet, W.E. Moerner and Noise2Void, A. Krull/Florian Jug). Particularly, the convolutional network architecture U-Net has become an important tool. To provide a user-friendly environment to apply those state-of-the art image analysis tools, Anna Kreshuk presented the iLastik platform as an easy to use tool. A new fundamental approach to handle, visualise and process the large amount of data coming from the microscopes was presented by Ivo Sbalzarini. Instead of using pixels to save an image, adaptive particles approximate the image content. Furthermore, Gaudenz Danuser gave a thought-provoking talk on how current perturbation-based approaches in cell biology can mislead us in our analysis. Danuser emphasised that the observed phenotype from a perturbation of a system (e.g. loss of a protein’s function) is not equal to the real function of the gene. For example, cutting a wire from the battery to the electronic board of radio would lead to the “phenotype” loss of sound. However, the function of the wire was simply to provide power to the radio, not to produce sound! As a better perturbation-free alternative, Danuser introduced a concept used in econometrics known as Granger causality.
Advances in biology
All of these new developments culminated in impressive new insights into biological processes. There were many talks on mitochondria and endoplasmic reticulum dynamics revealed by novel live-cell super-resolution techniques. Suliana Manley gave one of the most intriguing of those talks, on modes of asymmetric and symmetric mitochondrial division.
Jennifer Lippincott-Schwartz also gave a stunning presentation on how RNA granules can hitch a ride through an ANXA-11 mediated connection to lysosomes, and how ALS associated mutations in ANXA-11 break this connection. Furthermore, an intriguing new mRNA reading frame sensor (Moon and Sun tags) was presented by Sanne Boersma of the Tanenbaum lab to understand stochasticity of mRNA translation.
To conclude, the field of microscopy has grown so much that some may feel we have solved all the theoretical problems, and only engineering challenges are left – hardware improvements, new materials, new engineering solutions. At the closing dinner of the conference, however, Atsushi Miyawaki from RIKEN beautifully summarised how he felt about the future of microscopy, and of Seeing is Believing. Standing in the banquet hall of the Heidelberg Castle, he told us that castles in Japan remain unfinished. This state of incompletion is not due to any fault of the architects, but a feature of beauty, as it was believed that things that were incomplete had room to grow, and that growth is valuable. No matter how high our achievements are in the field of microscopy and image analysis, there will always be unforeseen avenues of growth. Attending Seeing is Believing has hopefully prepared us to follow those avenues, and to share what we find so we may all grow together.
A total of 189 posters were presented, from which two were singled out as the winners by popular vote.
Characterization of the genomic and splicing features of long non-coding RNAs using bioinformatics approaches
Authors: Monah Abou Alezz, Ludovica Celli, Giulia Belotti, Silvia Bione, Institute of Molecular Genetics L. L Cavalli-Sforza – National Research Council, Italy
Recent developments in deep sequencing approaches have simulated the continuous discovery of a significantly large number of novel long non-coding RNA (lncRNA) genes loci in the genomes. Long non-coding RNAs are recognized as a new class of regulatory molecules despite very little is known about their functions in the cellular processes. Due to their overall low expression level and tissue-specificity, the identification and annotation of lncRNA genes still remains challenging. The characterization of lncRNAs’ features is crucial to understand and get functional insights on their mechanisms of action. We exploited recent annotations by the GENCODE compendium to characterize the genomic and splicing features of long non-coding genes, in comparison to protein-coding ones, in the human and mouse genome by using bioinformatics approaches. Our analysis highlighted differences between the two classes of genes in terms of gene architecture regarding exons and introns length, GC-content, and the combinatorial patterns of chromatin marks and states. Moreover, significant differences in the splice sites usage were observed between long non-coding and protein-coding genes. While the frequency of non-canonical GC-AG splice junctions represents about 0.8% of total splice sites in protein-coding genes, we identified a remarkable enrichment of the GC-AG splice sites in long non-coding genes, both in human (3.0%) and mouse (1.9%). In addition, we identified peculiar characteristics of the GC-AG introns in terms of donor and acceptor splice sites strength, poly-pyrimidine tract, intron length, and a positional bias of GC-AG junctions being enriched in the first intron. Genes containing at least one GC-AG intron were found conserved in many species across large evolutionary distances, more prone to alternative splicing and a functional analysis pointed toward their enrichment in specific biological processes such as
Authors: Bastian Fromm (1), Diana Domanska (2), Eirik Hoye (3), Vladimir Ovchinnikov (4), Wenjing Kang (5), Ernesto Aparicio-Puerta (6), Morten Johansen (7), Kjersti Flatmark (3), Anthony Mathelier (8), Hovig
Eivind (3), Michael Hackenberg (6), Marc Friedländer (5), Kevin Peterson (9)
Non-coding RNAs (ncRNA) have gained substantial attention due to their roles in human disorders and animal development. microRNAs (miRNAs) are unique within this class as they are the only ncRNAs with individual gene sequences conserved across the animal kingdom. Bona fide miRNAs can be clearly distinguished from the myriad small RNAs generated in cells by a set of unique criteria. Unfortunately, recognition and utilization of these clear and mechanistically well understood features is not a common practice. We addressed this by extensively expanding our curated miRNA gene database MirGeneDB to 45 organisms that represent the breadth of Metazoa. By consistently annotating and naming more than 11,000 miRNA genes in these organisms, we show that previous miRNA annotations contained not only many false positives, but surprisingly many false negatives as well. Indeed, curated miRNA complements of closely related organisms are very similar and can be used to reconstruct evolution of miRNA genes, families and biogenesis across more than 1 billion years of evolution. MirGeneDB represents a robust platform for providing deeper and more significant insights into the biology of miRNAs, possible sources of mis-regulation, and evolutionary mechanisms. MirGeneDB is publicly and freely available under http://mirgenedb.org/.
(1) Science for Life Laboratory, Sweden (2) Department of Informatics, University of Oslo, Oslo, Norway (3) Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway (4) School of Life Sciences, Faculty of Health and Life Sciences, University of Nottingham, United Kingdom (5) Stockholm University, SciLifeLab, Sweden (6) Department of Genetics, Faculty of Sciences, University of Granada, Granada, Spain (7) Institute for Medical Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway (8) Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, Oslo, Norway (9) Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
Out of the 248 posters presented, 2 stood out from the rest and were awarded a poster prize based on popular vote. Here we present the abstracts and posters of the winners.
CalQTrace: Simultaneous Calculation and Quantification of 100,000 immune activation Traces at single-cell resolution using CNN
Authors: Liliana Barbieri (1), Kseniya Korobchevskaya (2), Azeem Ahmad (3), Huw Colin-York (1), Aurelien Barbotin (4), Glykeria Karanika (1), Loic Peters (5), Isabela Pedroza-Pacheco (4), Angela Lee (1), Lena Cords (1), Anish Priyadarshi (3), Dominic Waithe (6), Jana Kohler (6), Christoffer Lagerholm (6), Balpreet Singh Ahluwalia (3), Marco Fritzsche (2)
Quantification of immune cell activation is essential to the understanding of their effector function. Tracing activation signatures like cellular calcium release and the expression of surface markers in response to activation signals allows the classification of the course of immune cell activation from early triggering events to late differentiation. However, robust quantitative platforms for such measurements represent a major challenge, restricting the analysis to small single-cell population or more recently to cell ensembles with high-dimensional parameter analysis tools. Here, we introduce a combination of a convolutional neural network-based CalQTrace (Calculation and Quantification of Trace) software, together with a Graphical User Interface, and an optical high-throughput light-sheet platform, allowing the simultaneous fully automated quantitation of immune cell activation traces of >100,000 live immune cells. CalQTrace enables user-independent statistically robust classification and quantification of multiple fluorescent activation markers including calcium, CD25+/- expression, and cell viability tracking single cells in space and time within a 5 mm x 5 mm large-field-of-view, opening-up unprecedented insights into physiological activation tracing in living immune cells.
(1) MRC Human Immunology Unit, University of Oxford, United Kingdom (2) Kennedy Institute for Rheumatology, University of Oxford, United Kingdom (3) The Arctic University of Norway, Norway (4) University of Oxford, United Kingdom (5) University College London, United Kingdom (6) Weatherall Institute of Molecular Medicine, University of Oxford, United Kingdom
Poster currently not available
Bleaching-insensitive STED microscopy with exchangeable fluorescent probes
Authors: Christoph Spahn (1), Florian Hurter (1), Mathilda Glaesmann (1), Jonathan Grimm (2), Luke Lavis (2), Hans-Dieter Barth (1), Marko Lampe (3), Mike Heilemann (1)
Photobleaching affects image quality and resolution in fluorescence microscopy, and thus limits the extractable information. This is in particular relevant for super-resolution microscopy where typically high laser intensities are used. In order to minimize photobleaching, we repurposed the use of exchangeable fluorescent probes, as used in single-molecule localisation microscopy methods such as Point Accumulation for Imaging in Nanoscale Tomography (PAINT) , for STED microscopy. We demonstrate pseudo-permanent labeling of target structures and constant exchange of photobleached fluorophores. This concept allows for whole-cell, 3D, multi-color and live-cell STED microscopy . Using transiently binding hydrophobic dyes and fluorophore-labeled major minor groove binders [3, 4], we visualised the nanostructure of chromatin, cell membranes and organelles in bacterial and mammalian cells in 3D. To expand the range of targets, we employed oligonucleotide-labeled antibodies that transiently bind fluorophore-labeled oligonucleotides, as used in single-molecule super-resolution imaging with DNA-PAINT , and demonstrate multi-color STED imaging.
 Sharanov and Hochstrasser, PNAS 103 (50), 18911-18916 (2006)
 Spahn et al., Nano Letters 19 (1), 500-505 (2019)
 Lukinavičius et al., Nature Communications 6, 8497 (2015)
 Spahn et al., Scientific Reports 8, 14768 (2018)
 Schnitzbauer et al., Nature Protocols 12(6), 1198-1228 (2017)
Is there a sound from your childhood that just carries you back? For me, one of those is the opening credits of the Tintinanimated show. That’s why I’m really grateful that I can click on a link and find it online and travel back in space and time pretty much at will.
As an archivist, though, I am acutely aware of the work that goes behind maintaining access to the world’s audiovisual heritage for future generations. Think about all those films, sound recordings, radio and TV programmes that are created everyday and capture unique records of activities, events and exchanges. But these exist in many formats, from wax cylinders to Super 8 films, .mp3 files or VHS tapes, and require specific hardware (such as VCRs, projectors, etc…) or software (like MPlayer, QuickTime media player) that can render the recordings.
In the course of its activities, and in particular its training activities undertaken by the EMBL Course and Conference Office, some audiovisual material might be created, most likely recordings of talks. This is a great way to create a trace of the meeting that can complement abstract books in an engaging format. It then also makes it easy to share these recordings and help disseminate knowledge further when some of these are made available for all to see through various channels, such at the EMBL YouTube “Keynotes @ EMBL” playlist. Even if you weren’t at the event, you can join in long after they have ended.
Nowadays, these videos are likely born-digital, straight into a format that you can watch on your laptop. But in earlier times, this is what you might have created:
Or even, earlier, this:
Luckily, when such things end up with me in the EMBL Archive, I can contact my colleagues in the EMBL Photolab, our in-house AV department to create digital files of these. They have the equipment that helps migrate the contents of these films into digital formats.
But whether these are born-digital or migrated, they all need to be preserved to ensure ongoing access to them. Because indeed, nothing is ever preserved – it is only ever being preserved.
Unfortunately, though, it happens that things are lost… With these discs, I have not been so fortunate and the video content contained on this CRVdisc could not be retrieved.
So, next time you are at a conference, and there’s a film crew, or when you are being interviewed on the radio – think about these traces you are leaving behind, that will traverse time so that future generations can look at your work and hear your voice in new formats, on machines we can’t yet fathom, and through these, make a connection with you as an individual presenter.