level-one heading

Writers
Data Analysts
Consultants
Product Developers
Researchers
Why Kolabtree
Getting started is quick and easy. No upfront fees
It’s free to request a service and invite bids from experts
Discuss requirements with the expert in detail before accepting statement of work from Kolabtree
Collaborate with the expert directly to get your work done the right way
Fund project when you hire the expert, but approve the deliverables only once work is done
Want to hire this expert for a project? Request a quote for free.
Profile Details
Create Project
★★★★★
☆☆☆☆☆
USD 125 /hr
Hire Dr. Reynaud E.
France
USD 125 /hr

25 years expertise in Cell Biology, Tissue Engineering and Optical Microscopy, R&D and >100 publications

Profile Summary
Subject Matter Expertise
Services
Writing Medical Writing, Technical Writing, Copywriting, Creative Writing, Newswriting, Audio Transcription, General Proofreading & Editing, Translation
Work Experience

Co-Founder and Lead Scientist

Rezero Ltd

August 2021 - Present

Assistant Professor

University College Dublin College of Science

January 2009 - Present

Life Science Consultant

SAFE (PARIS) NGO Harm Reduction

January 2003 - Present

Founder, CEO

NAIAD 3D BIOPRINTING LIMITED

January 2016 - January 2023

Post doctoral Fellow / Research Assistant

European Molecular Biology Laboratory

September 2001 - January 2009

Education

Ph.D. Cell oncology

Université Paris Sud (Paris XI) - France

September 1995 - July 1999

Certifications
  • Certification details not provided.
Publications
JOURNAL ARTICLE
Niamh Burke, Gesine Müller, Vittorio Saggiomo, Amy Ruth Hassett, Jérôme Mutterer, Patrick Ó Súilleabháin, Daniel Zakharov, Donal Healy, Emmanuel G. Reynaud, Mark Pickering (2024). EnderScope: a low-cost 3D printer-based scanning microscope for microplastic detection . Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.
Andrea Souza, McCarthy Kevin, Brian J Rodriguez, Emmanuel G Reynaud (2024). The use of fluid-phase 3D printing to pattern alginate-gelatin hydrogel properties to guide cell growth and behaviour in vitro . Biomedical Materials.
Krutika Singh, Jacek K. Wychowaniec, Charlotte J.C. Edwards-Gayle, Emmanuel G. Reynaud, Brian J. Rodriguez, Dermot F. Brougham (2024). Structure-dynamics correlations in composite PF127-PEG-based hydrogels; cohesive/hydrophobic interactions determine phase and rheology and identify the role of micelle concentration in controlling 3D extrusion printability . Journal of Colloid and Interface Science.
Andrea Souza, Matthew Parnell, Brian J. Rodriguez, Emmanuel G. Reynaud (2023). Role of pH and Crosslinking Ions on Cell Viability and Metabolic Activity in Alginate–Gelatin 3D Prints . Gels.
Emmanuel Reynaud, Andrea Souza, Matthew Parnell, Brian Rodriguez (2023). Role of pH and Crosslinking Ions on Cell Viability and Metabolic Activity in Alginate–Gelatin 3D Prints . Gels.
Johannes Hohlbein, Benedict Diederich, Barbora Marsikova, Emmanuel G. Reynaud, Séamus Holden, Wiebke Jahr, Robert Haase, Kirti Prakash(2022). Open microscopy in the life sciences: quo vadis? . Nature Methods. Springer Science and Business Media {LLC}
The biology of imaging <head> <META HTTP-EQUIV="Refresh" CONTENT="0;URL=/servlet/useragent"> </head> . Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.
Spatiotemporally Resolved Heat Dissipation in 3D Patterned Magnetically Responsive Hydrogels @article{PMID:33369876,Title={Spatiotemporally Resolved Heat Dissipation in 3D Patterned Magnetically Responsive Hydrogels},Author={Monks, Patricia and Wychowaniec, Jacek K and McKiernan, Eoin and Clerkin, Shane and Crean, John and Rodriguez, Brian J and Reynaud, Emmanuel G and Heise, Andreas and Brougham, Dermot F},DOI={10.1002/smll.202004452},Number={5},Volume={17},Month={February},Year={2021},Journal={Small (Weinheim an der Bergstrasse, Germany)},ISSN={1613-6810},Pages={e2004452},Abstract={Multifunctional nanocomposites that exhibit well-defined physical properties and encode spatiotemporally controlled responses are emerging as components for advanced responsive systems, for example, in soft robotics or drug delivery. Here an example of such a system, based on simple magnetic hydrogels composed of iron oxide magnetic nanoflowers and Pluronic F127 that generates heat upon alternating magnetic field irradiation is described. Rules for heat-induction in bulk hydrogels and the heat-dependence on particle concentration, gel volume, and gel exposed surface area are established, and the dependence on external environmental conditions in "closed" as compared to "open" (cell culture) system, with controllable heat jumps, of ∆T 0-12°C, achieved within ≤10 min and maintained described. Furthermore the use of extrusion-based 3D printing for manipulating the spatial distribution of heat in well-defined printed features with spatial resolution &lt;150 µm, sufficiently fine to be of relevance to tissue engineering, is presented. Finally, localized heat induction in printed magnetic hydrogels is demonstrated through spatiotemporally-controlled release of molecules (in this case the dye methylene blue). The study establishes hitherto unobserved control over combined spatial and temporal induction of heat, the applications of which in developing responsive scaffold remodeling and cargo release for applications in regenerative medicine are discussed.},URL={https://doi.org/10.1002/smll.202004452}} . Small (Weinheim an der Bergstrasse, Germany).
(2020). 3D imaging of undissected optically cleared Anopheles stephensi mosquitoes and midguts infected with Plasmodium parasites . PloS one.
(2020). HaRePo (harm reduction by post): an innovative and effective harm reduction programme for people who use drugs using email, telephone, and post service . Harm reduction journal.
(2019). The Tara Pacific expedition-A pan-ecosystemic approach of the "-omics" complexity of coral reef holobionts across the Pacific Ocean . PLoS biology.
(2018). A global ocean atlas of eukaryotic genes . Nature communications.
(2017). Reading the Evolution of Compartmentalization in the Ribosome Assembly Toolbox: The YRG Protein Family . PloS one.
Assessing phototoxicity in live fluorescence imaging @article{PMID:28661494,Title={Assessing phototoxicity in live fluorescence imaging},Author={Laissue, P Philippe and Alghamdi, Rana A and Tomancak, Pavel and Reynaud, Emmanuel G and Shroff, Hari},DOI={10.1038/nmeth.4344},Number={7},Volume={14},Month={June},Year={2017},Journal={Nature methods},ISSN={1548-7091},Pages={657—661},Abstract={Are the answers to biological questions obtained via live fluorescence microscopy substantially affected by phototoxicity? Although a single set of standards for assessing phototoxicity cannot exist owing to the breadth of samples and experimental questions associated with biological imaging, we need quantitative, practical assessments and reporting standards to ensure that imaging has a minimal impact on observed biological processes and sample health. Here we discuss the problem of phototoxicity in biology and suggest guidelines to improve its reporting and assessment.},URL={https://doi.org/10.1038/nmeth.4344}} . Nature methods.
A 3-D cell culture system to study epithelia functions using microcarriers @article{PMID:26847791,Title={A 3-D cell culture system to study epithelia functions using microcarriers},Author={Jakob, Petra H and Kehrer, Jessica and Flood, Peter and Wiegel, Catharina and Haselmann, Uta and Meissner, Markus and Stelzer, Ernst H K and Reynaud, Emmanuel G},DOI={10.1007/s10616-015-9935-0},Number={5},Volume={68},Month={October},Year={2016},Journal={Cytotechnology},ISSN={0920-9069},Pages={1813—1825},Abstract={In vitro cell culture models used to study epithelia and epithelial diseases would benefit from the recognition that organs and tissues function in a three-dimensional (3D) environment. This context is necessary for the development of cultures that more realistically resemble in vivo tissues/organs. Our aim was to establish and characterize biologically meaningful 3D models of epithelium. We engineered 3D epithelia cultures using a kidney epithelia cell line (MDCK) and spherical polymer scaffolds. These kidney epithelia were characterized by live microscopy, immunohistochemistry and transmission electron microscopy. Strikingly, the epithelial cells displayed increased physiological relevance; they were extensively polarized and developed a more differentiated phenotype. Using such a growth system allows for direct transmission and fluorescence imaging with few restrictions using wide-field, confocal and Light Sheet Fluorescence Microscopy. We also assessed the wider relevance of this 3D culturing technique with several epithelial cell lines. Finally, we established that these 3D micro-tissues can be used for infection as well as biochemical assays and to study important cellular processes such as epithelial mesenchymal transmission. This new biomimetic model could provide a broadly applicable 3D culture system to study epithelia and epithelia related disorders.},URL={https://europepmc.org/articles/PMC5023556}} . Cytotechnology.
Material- and feature-dependent effects on cell adhesion to micro injection moulded medical polymers @article{PMID:27137802,Title={Material- and feature-dependent effects on cell adhesion to micro injection moulded medical polymers},Author={Choi, Seong Ying and Habimana, Olivier and Flood, Peter and Reynaud, Emmanuel G and Rodriguez, Brian J and Zhang, Nan and Casey, Eoin and Gilchrist, Michael D},DOI={10.1016/j.colsurfb.2016.04.032},Volume={145},Month={September},Year={2016},Journal={Colloids and surfaces. B, Biointerfaces},ISSN={0927-7765},Pages={46—54},Abstract={Two polymers, polymethylmethacrylate (PMMA) and cyclic olefin copolymer (COC), containing a range of nano- to micron- roughness surfaces (Ra 0.01, 0.1, 0.4, 1.0, 2.0, 3.2 and 5.0μm) were fabricated using electrical discharge machining (EDM) and replicated using micro injection moulding (μIM). Polymer samples were characterized using optical profilometry, atomic force microscopy (AFM) and water surface contact angle. Cell adhesion tests were carried out using bacterial Pseudomonas fluorescens and mammalian Madin-Darby Canine Kidney (MDCK) cells to determine the effect of surface hydrophobicity, surface roughness and stiffness. It is found that there are features which gave insignificant differences (feature-dependent effect) in cell adhesion, albeit a significant difference in the physicochemical properties (material-dependent effect) of substrata. In bacterial cell adhesion, the strongest feature-dependence is found at Ra 0.4μm surfaces, with material-dependent effects strongest at Ra 0.01μm. Ra 0.1μm surfaces exhibited strongest feature-dependent effects and Ra 5.0μm has strongest material-dependent effects on mammalian cell adhesion. Bacterial cell adhesion is found to be favourable to hydrophobic surfaces (COC), with the lowest adhesion at Ra 0.4μm for both materials. Mammalian cell adhesion is lowest in Ra 0.1μm and highest in Ra 1.0μm, and generally favours hydrophilic surfaces (PMMA). These findings can be used as a basis for developing medical implants or microfluidic devices using micro injection moulding for diagnostic purposes, by tuning the cell adhesion on different areas containing different surface roughnesses on the diagnostic microfluidic devices or medical implants.},URL={https://doi.org/10.1016/j.colsurfb.2016.04.032}} . Colloids and surfaces. B, Biointerfaces.
Using hydrogels in microscopy: A tutorial @article{PMID:26921550,Title={Using hydrogels in microscopy: A tutorial},Author={Flood, Peter and Page, Henry and Reynaud, Emmanuel G},DOI={10.1016/j.micron.2016.02.002},Volume={84},Month={May},Year={2016},Journal={Micron (Oxford, England : 1993)},ISSN={0968-4328},Pages={7—16},Abstract={Sample preparation for microscopy is a crucial step to ensure the best experimental outcome. It often requires the use of specific mounting media that have to be tailored to not just the sample but the chosen microscopy technique. The media must not damage the sample or impair the optical path, and may also have to support the correct physiological function/development of the sample. For decades, researchers have used embedding media such as hydrogels to maintain samples in place. Their ease of use and transparency has promoted them as mainstream mounting media. However, they are not as straightforward to implement as assumed. They can contain contaminants, generate forces on the sample, have complex diffusion and structural properties that are influenced by multiple factors and are generally not designed for microscopy in mind. This short review will discuss the advantages and disadvantages of using hydrogels for microscopy sample preparation and highlight some of the less obvious problems associated with the area.},URL={https://doi.org/10.1016/j.micron.2016.02.002}} . Micron (Oxford, England : 1993).
(2016). End to End Digitisation and Analysis of Three-Dimensional Coral Models, from Communities to Corallites . PloS one.
Guide to light-sheet microscopy for adventurous biologists @article{PMID:25549268,Title={Guide to light-sheet microscopy for adventurous biologists},Author={Reynaud, Emmanuel G and Peychl, Jan and Huisken, Jan and Tomancak, Pavel},DOI={10.1038/nmeth.3222},Number={1},Volume={12},Month={January},Year={2015},Journal={Nature methods},ISSN={1548-7091},Pages={30—34},URL={https://doi.org/10.1038/nmeth.3222}} . Nature methods.
(2015). Ocean plankton. Patterns and ecological drivers of ocean viral communities . Science (New York, N.Y.).
(2015). Ocean plankton. Structure and function of the global ocean microbiome . Science (New York, N.Y.).
(2015). Open science resources for the discovery and analysis of Tara Oceans data . Scientific data.
(2015). Ocean plankton. Environmental characteristics of Agulhas rings affect interocean plankton transport . Science (New York, N.Y.).
(2015). Ocean plankton. Eukaryotic plankton diversity in the sunlit ocean . Science (New York, N.Y.).
(2015). Ocean plankton. Determinants of community structure in the global plankton interactome . Science (New York, N.Y.).
(2014). Long-term survey of a syringe-dispensing machine needle exchange program: answering public concerns . Harm reduction journal.
Three-dimensional tissue cultures: current trends and beyond @article{PMID:22729488,Title={Three-dimensional tissue cultures: current trends and beyond},Author={Page, Henry and Flood, Peter and Reynaud, Emmanuel G},DOI={10.1007/s00441-012-1441-5},Number={1},Volume={352},Month={April},Year={2013},Journal={Cell and tissue research},ISSN={0302-766X},Pages={123—131},Abstract={Life science research focuses on deciphering the biochemical mechanisms that regulate cell proliferation and function and largely depends on the use of tissue culture methods in which cells are grown on two-dimensional hard plastic or glass surfaces. However, the flat surface of the tissue culture plate represents a poor topological approximation of the complex three-dimensional (3D) architecture of a tissue or organ composed of various cell types, extracellular matrix (ECM) and interstitial fluids. Moreover, if we consider a cell as a perfectly defined volume, flattened cells have full access to the environment and limited cell-to-cell contact. However if the cell is a cube in a simple cuboidal epithelium, then its access to the lumen is limited to one face, with the opposite face facing the basal membrane and the remaining four faces lying in close contact with neighbouring cells. This is of great importance when considering the access of viruses and bacteria to the cell surface, the excretion of soluble factors or proteins or the signalling within or between cells. This short review discusses various cell culture approaches to improve the simulation of the 3D environment of cells.},URL={https://doi.org/10.1007/s00441-012-1441-5}} . Cell and tissue research.
(2011). A holistic approach to marine eco-systems biology . PLoS biology.
A novel laser nanosurgery approach supports de novo Golgi biogenesis in mammalian cells @article{PMID:21378314,Title={A novel laser nanosurgery approach supports de novo Golgi biogenesis in mammalian cells},Author={Tängemo, Carolina and Ronchi, Paolo and Colombelli, Julien and Haselmann, Uta and Simpson, Jeremy C and Antony, Claude and Stelzer, Ernst H K and Pepperkok, Rainer and Reynaud, Emmanuel G},DOI={10.1242/jcs.079640},Number={Pt 6},Volume={124},Month={March},Year={2011},Journal={Journal of cell science},ISSN={0021-9533},Pages={978—987},Abstract={The Golgi complex has a central role in the secretory pathway of all higher organisms. To explain the synthesis of its unique stacked structure in mammalian cells, two major models have been proposed. One suggests that it is synthesized de novo from the endoplasmic reticulum. The second model postulates a pre-existing Golgi template that serves as a scaffold for its biogenesis. To test these hypotheses directly, we have developed an approach in which we deplete the Golgi complex from living cells by laser nanosurgery, and subsequently analyze the 'Golgi-depleted' karyoplast using time-lapse and electron microscopy. We show that biosynthetic transport is blocked after Golgi depletion, but is restored 12 hours later. This recovery of secretory transport coincides with an ordered assembly of stacked Golgi structures, and we also observe the appearance of matrix proteins before that of Golgi enzymes. Functional experiments using RNA interference-mediated knockdown of GM130 further demonstrate the importance of the matrix during Golgi biogenesis. By contrast, the centrosome, which can also be removed by laser nanosurgery and is not reformed within the considered time frame, is not required for this process. Altogether, our data provide evidence that de novo Golgi biogenesis can occur in mammalian cells.},URL={http://jcs.biologists.org/cgi/content/full/124/6/978}} . Journal of cell science.
Transitional forms between the three domains of life and evolutionary implications @article{PMID:21920985,Title={Transitional forms between the three domains of life and evolutionary implications},Author={Reynaud, Emmanuel G and Devos, Damien P},DOI={10.1098/rspb.2011.1581},Number={1723},Volume={278},Month={November},Year={2011},Journal={Proceedings. Biological sciences},ISSN={0962-8452},Pages={3321—3328},Abstract={The question as to the origin and relationship between the three domains of life is lodged in a phylogenetic impasse. The dominant paradigm is to see the three domains as separated. However, the recently characterized bacterial species have suggested continuity between the three domains. Here, we review the evidence in support of this hypothesis and evaluate the implications for and against the models of the origin of the three domains of life. The existence of intermediate steps between the three domains discards the need for fusion to explain eukaryogenesis and suggests that the last universal common ancestor was complex. We propose a scenario in which the ancestor of the current bacterial Planctomycetes, Verrucomicrobiae and Chlamydiae superphylum was related to the last archaeal and eukaryotic common ancestor, thus providing a way out of the phylogenetic impasse.},URL={https://europepmc.org/articles/PMC3177640}} . Proceedings. Biological sciences.
Three-dimensional Fluorescence Lifetime Imaging with a Single Plane Illumination Microscope provides an improved signal to noise ratio @article{PMID:21997084,Title={Three-dimensional Fluorescence Lifetime Imaging with a Single Plane Illumination Microscope provides an improved signal to noise ratio},Author={Greger, Klaus and Neetz, Manuel J and Reynaud, Emmanuel G and Stelzer, Ernst H K},DOI={10.1364/oe.19.020743},Number={21},Volume={19},Month={October},Year={2011},Journal={Optics express},ISSN={1094-4087},Pages={20743—20750},Abstract={We designed a widefield frequency domain Fluorescence Lifetime Imaging Microscopy (FLIM)setup, which is based on a Single Plane Illumination Microscope (SPIM). A SPIM provides an inherent optical sectioning capability and reduces photobleaching compared to conventional widefield and confocal fluorescence microscopes. The lifetime precision of the FLIM was characterized with Rhodamine 6G solutions of different quencher concentrations [KI]. We demonstrate the high spatial resolution of the SPIM-FLIM combination in the intensity domain as well as in the lifetime domain with latex bead samples and multiple recordings of three-dimensional live Madine-Darby Canine Kidney (MDCK) cysts. We estimate that the bleaching rate after 600 images have been recorded is below 5%.},URL={https://doi.org/10.1364/OE.19.020743}} . Optics express.
Meeting report: first light sheet based fluorescence microscopy workshop @article{PMID:20652906,Title={Meeting report: first light sheet based fluorescence microscopy workshop},Author={Reynaud, Emmanuel G and Tomancak, Pavel},DOI={10.1002/biot.201000177},Number={8},Volume={5},Month={August},Year={2010},Journal={Biotechnology journal},ISSN={1860-6768},Pages={798—804},URL={https://doi.org/10.1002/biot.201000177}} . Biotechnology journal.
Evolution. Intermediate steps @article{PMID:21109658,Title={Evolution. Intermediate steps},Author={Devos, Damien P and Reynaud, Emmanuel G},DOI={10.1126/science.1196720},Number={6008},Volume={330},Month={November},Year={2010},Journal={Science (New York, N.Y.)},ISSN={0036-8075},Pages={1187—1188},URL={http://www.sciencemag.org/cgi/content/full/330/6008/1187}} . Science (New York, N.Y.).
Mechanosensing in actin stress fibers revealed by a close correlation between force and protein localization @article{PMID:19401336,Title={Mechanosensing in actin stress fibers revealed by a close correlation between force and protein localization},Author={Colombelli, Julien and Besser, Achim and Kress, Holger and Reynaud, Emmanuel G and Girard, Philippe and Caussinus, Emmanuel and Haselmann, Uta and Small, John V and Schwarz, Ulrich S and Stelzer, Ernst H K},DOI={10.1242/jcs.042986},Number={Pt 10},Volume={122},Month={May},Year={2009},Journal={Journal of cell science},ISSN={0021-9533},Pages={1665—1679},Abstract={The mechanics of the actin cytoskeleton have a central role in the regulation of cells and tissues, but the details of how molecular sensors recognize deformations and forces are elusive. By performing cytoskeleton laser nanosurgery in cultured epithelial cells and fibroblasts, we show that the retraction of stress fibers (SFs) is restricted to the proximity of the cut and that new adhesions form at the retracting end. This suggests that SFs are attached to the substrate. A new computational model for SFs confirms this hypothesis and predicts the distribution and propagation of contractile forces along the SF. We then analyzed the dynamics of zyxin, a focal adhesion protein present in SFs. Fluorescent redistribution after laser nanosurgery and drug treatment shows a high correlation between the experimentally measured localization of zyxin and the computed localization of forces along SFs. Correlative electron microscopy reveals that zyxin is recruited very fast to intermediate substrate anchor points that are highly tensed upon SF release. A similar acute localization response is found if SFs are mechanically perturbed with the cantilever of an atomic force microscope. If actin bundles are cut by nanosurgery in living Drosophila egg chambers, we also find that zyxin redistribution dynamics correlate to force propagation and that zyxin relocates at tensed SF anchor points, demonstrating that these processes also occur in living organisms. In summary, our quantitative analysis shows that force and protein localization are closely correlated in stress fibers, suggesting a very direct force-sensing mechanism along actin bundles.},URL={http://jcs.biologists.org/cgi/content/full/122/10/1665}} . Journal of cell science.
A correlative light and electron microscopy method based on laser micropatterning and etching @article{PMID:19066029,Title={A correlative light and electron microscopy method based on laser micropatterning and etching},Author={Colombelli, Julien and Tängemo, Carolina and Haselman, Uta and Antony, Claude and Stelzer, Ernst H K and Pepperkok, Rainer and Reynaud, Emmanuel G},DOI={10.1007/978-1-59745-261-8_15},Volume={457},Year={2008},Journal={Methods in molecular biology (Clifton, N.J.)},ISSN={1064-3745},Pages={203—213},Abstract={Correlative microscopy is a hybrid method that allows the localization of events observed under visible, ultraviolet, or infrared light, at molecular and submolecular levels, combining two microscopy techniques. However, the main limitation of correlative microscopy is to develop a labeling technique that can be easily used first in light and then in electron microscopy. Laser etching is a well-established method to create precisely designed shapes or volumes in various materials including glass. We have applied this technique to develop a new correlative light and electron microscopy method and to apply it in our study of the Golgi apparatus. The location of the cell of interest is laser-inscribed into the glass allowing a simple follow-up in light and fluorescence microscopy. Furthermore, the glass surface is laser-etched and upon fixation and flat embedding, the inverse ridge can be localized as well as the cell of interest, which is then processed for electron microscopy.},URL={https://doi.org/10.1007/978-1-59745-261-8_15}} . Methods in molecular biology (Clifton, N.J.).
Light sheet-based fluorescence microscopy: more dimensions, more photons, and less photodamage @article{PMID:19404438,Title={Light sheet-based fluorescence microscopy: more dimensions, more photons, and less photodamage},Author={Reynaud, Emmanuel G and Krzic, Uros and Greger, Klaus and Stelzer, Ernst H K},DOI={10.2976/1.2974980},Number={5},Volume={2},Month={October},Year={2008},Journal={HFSP journal},ISSN={1955-2068},Pages={266—275},Abstract={Light-sheet-based fluorescence microscopy (LSFM) is a fluorescence technique that combines optical sectioning, the key capability of confocal and two-photon fluorescence microscopes with multiple-view imaging, which is used in optical tomography. In contrast to conventional wide-field and confocal fluorescence microscopes, a light sheet illuminates only the focal plane of the detection objective lens from the side. Excitation is, thus, restricted to the fluorophores in the volume near the focal plane. This provides optical sectioning and allows the use of regular cameras in the detection process. Compared to confocal fluorescence microscopy, LSFM reduces photo bleaching and photo toxicity by up to three orders of magnitude. In LSFM, the specimen is embedded in a transparent block of hydrogel and positioned relative to the stationary light sheet using precise motorized translation and rotation stages. This feature is used to image any plane in a specimen. Additionally, multiple views obtained along different angles can be combined into a single data set with an improved resolution. LSFMs are very well suited for imaging large live specimens over long periods of time. However, they also perform well with very small specimens such as single yeast cells. This perspective introduces the principles of LSFM, explains the challenges of specimen preparation, and introduces the basics of a microscopy that takes advantage of multiple views.},URL={https://europepmc.org/articles/PMC2639947}} . HFSP journal.
In migrating cells, the Golgi complex and the position of the centrosome depend on geometrical constraints of the substratum @article{PMID:18577576,Title={In migrating cells, the Golgi complex and the position of the centrosome depend on geometrical constraints of the substratum},Author={Pouthas, François and Girard, Philippe and Lecaudey, Virginie and Ly, Thi Bach Nga and Gilmour, Darren and Boulin, Christian and Pepperkok, Rainer and Reynaud, Emmanuel G},DOI={10.1242/jcs.026849},Number={Pt 14},Volume={121},Month={July},Year={2008},Journal={Journal of cell science},ISSN={0021-9533},Pages={2406—2414},Abstract={Although cells migrate in a constrained 3D environment in vivo, in-vitro studies have mainly focused on the analysis of cells moving on 2D substrates. Under such conditions, the Golgi complex is always located towards the leading edge of the cell, suggesting that it is involved in the directional movement. However, several lines of evidence indicate that this location can vary depending on the cell type, the environment or the developmental processes. We have used micro contact printing (microCP) to study the migration of cells that have a geometrically constrained shape within a polarized phenotype. Cells migrating on micropatterned lines of fibronectin are polarized and migrate in the same direction. Under such conditions, the Golgi complex and the centrosome are located behind the nucleus. In addition, the Golgi complex is often displaced several micrometres away from the nucleus. Finally, we used the zebrafish lateral line primordium as an in-vivo model of cells migrating in a constrained environment and observe a similar localization of both the Golgi and the centrosome in the leading cells. We propose that the positioning of the Golgi complex and the centrosome depends on the geometrical constraints applied to the cell rather than on a precise migratory function in the leading region.},URL={http://jcs.biologists.org/cgi/content/full/121/14/2406}} . Journal of cell science.
The third dimension bridges the gap between cell culture and live tissue @article{PMID:17684528,Title={The third dimension bridges the gap between cell culture and live tissue},Author={Pampaloni, Francesco and Reynaud, Emmanuel G and Stelzer, Ernst H K},DOI={10.1038/nrm2236},Number={10},Volume={8},Month={October},Year={2007},Journal={Nature reviews. Molecular cell biology},ISSN={1471-0072},Pages={839—845},Abstract={Moving from cell monolayers to three-dimensional (3D) cultures is motivated by the need to work with cellular models that mimic the functions of living tissues. Essential cellular functions that are present in tissues are missed by 'petri dish'-based cell cultures. This limits their potential to predict the cellular responses of real organisms. However, establishing 3D cultures as a mainstream approach requires the development of standard protocols, new cell lines and quantitative analysis methods, which include well-suited three-dimensional imaging techniques. We believe that 3D cultures will have a strong impact on drug screening and will also decrease the use of laboratory animals, for example, in the context of toxicity assays.},URL={https://doi.org/10.1038/nrm2236}} . Nature reviews. Molecular cell biology.
Investigating relaxation processes in cells and developing organisms: from cell ablation to cytoskeleton nanosurgery @article{PMID:17586260,Title={Investigating relaxation processes in cells and developing organisms: from cell ablation to cytoskeleton nanosurgery},Author={Colombelli, Julien and Reynaud, Emmanuel G and Stelzer, Ernst H K},DOI={10.1016/s0091-679x(06)82008-x},Volume={82},Year={2007},Journal={Methods in cell biology},ISSN={0091-679X},Pages={267—291},Abstract={Dynamic microscopy of living cells and organisms alone does not reveal the high level of complexity of cellular and subcellular organization. All observable processes rely on the activity of biochemical and biophysical processes and many occur at a physiological equilibrium. Experimentally, it is not trivial to apply a perturbation that targets a specific process without perturbing the overall equilibrium of a cell. Drugs and more recently RNAi certainly have general and undesired effects on cell physiology and metabolism. In particular, they affect the entire cell. Pulsed lasers allow to severe biological tissues with a precision in the range of hundreds of nanometers and to achieve ablation on the level of a single cell or a subcellular compartment. In this chapter, we present an efficient implementation of a picosecond UV-A pulsed laser-based nanosurgery system and review the different mechanisms of ablation that can be achieved at different levels of cellular organization. We discuss the performance of the ablation process in terms of the energy deposited onto the sample and compare our implementation to others recently employed for cellular and subcellular surgery. Above the energy threshold of ionization, we demonstrate how to achieve single-cell ablation through the induction of mechanical perturbation and cavitation in living organisms. Below this threshold, we induce cytoskeleton severing inside live cells. By combining nanosurgery with fast live-imaging fluorescence microscopy, we show how the apparent equilibrium of the cytoskeleton can be perturbed regionally inside a cell.},URL={https://doi.org/10.1016/S0091-679X(06)82008-X}} . Methods in cell biology.
Three-dimensional laser microsurgery in light-sheet based microscopy (SPIM) @article{PMID:19546948,Title={Three-dimensional laser microsurgery in light-sheet based microscopy (SPIM)},Author={Engelbrecht, Christoph J and Greger, Klaus and Reynaud, Emmanuel G and Krzic, Uros and Colombelli, Julien and Stelzer, Ernst H},DOI={10.1364/oe.15.006420},Number={10},Volume={15},Month={May},Year={2007},Journal={Optics express},ISSN={1094-4087},Pages={6420—6430},Abstract={Advances in the life sciences rely on the ability to observe dynamic processes in live systems and in environments that mimic in-vivo situations. Therefore, new methodological developments have to provide environments that resemble physiologically and clinically relevant conditions as closely as possible. In this work, plasma-induced laser nanosurgery for three-dimensional sample manipulation and sample perturbation is combined with optically sectioning light-sheet based fluorescence microscopy (SPIM) and applied to three-dimensional biological model systems. This means: a) working with a biological system that is not confined to essentially two dimensions like cell cultures on cover glasses, b) gaining intrinsic optical sectioning capabilities by an efficient three-dimensional fluorescence imaging system, and c) using arbitrarily-shaped three-dimensional ablation-patterns by a plasma-induced laser ablation system that prevent damage to surrounding tissues. Spatial levels in our biological applications range from sub-microns during delicate ablation of single microtubules over the confined disruption of cell membranes in an MDCK-cyst to the macroscopic cutting of a millimeter-sized Zebrafish caudal fin with arbitrary three-dimensional ablation patterns. Dynamic processes like laser-induced hemocyte migration can be studied with our SPIM-microscalpel in intact, live embryos.},URL={https://doi.org/10.1364/oe.15.006420}} . Optics express.
Detection and quantification of protein-microtubules interactions using green fluorescent protein photoconversion @article{PMID:17004326,Title={Detection and quantification of protein-microtubules interactions using green fluorescent protein photoconversion},Author={Brunet, Stéphane and Zimmermann, Timo and Reynaud, Emmanuel G and Vernos, Isabelle and Karsenti, Eric and Pepperkok, Rainer},DOI={10.1111/j.1600-0854.2006.00463.x},Number={9},Volume={7},Month={September},Year={2006},Journal={Traffic (Copenhagen, Denmark)},ISSN={1398-9219},Pages={1283—1289},Abstract={We present an in vitro system to analyze quantitatively the interactions of green fluorescent protein (GFP)-tagged recombinant proteins with microtubules. This method relies on photoconversion of GFP and time-lapse microscopy. Specific interactions can be detected and binding kinetics can be determined rapidly and accurately. This method provides an alternative to classical in vitro microtubule-binding assays to analyze microtubule-associated proteins binding to microtubules. It has the potential to be extended to study interactions of proteins or multi-protein complexes with different biopolymers like actin microfilaments or organelle membranes.},URL={https://doi.org/10.1111/j.1600-0854.2006.00463.x}} . Traffic (Copenhagen, Denmark).
[Laser nanosurgery in cell biology] @article{PMID:16828043,Title={[Laser nanosurgery in cell biology]},Author={Colombelli, Julien and Pepperkok, Rainer and Stelzer, Ernst H K and Reynaud, Emmanuel G},DOI={10.1051/medsci/20062267651},Number={6-7},Volume={22},Year={2006},Journal={Medecine sciences : M/S},ISSN={0767-0974},Pages={651—658},Abstract={Since their first use in the early 60's, pulsed lasers have become increasingly popular for their ability to ablate biological tissue. Short laser pulses allow high precision surgery for biological and medical applications with minimal invasiveness. Performing highly targeted manipulation and ablation allows experiments impossible so far in development biology, cellular biology or even assisted reproductive technologies and laser surgery has been increasingly used over the last five years to answer key questions in Biology. Recently, picosecond UV and femtosecond IR laser pulses have been used to cleave microtubules and to severe actin stress fibers in vivo with a spatial precision in the submicrometer range to study their dynamics without affecting cell viability. We review recent findings on the underlying principles of pulsed laser nanosurgery mechanisms showing how the use of ultra short laser pulses increases precision and non-invasiveness of laser surgery. We show how the understanding of the surgical process allows one to distinguish between single cell ablation in living organisms or intracellular nanosurgery in living cells and we review recent applications to the study of forces and the quantification of cytoskeleton dynamics.},URL={https://doi.org/10.1051/medsci/20062267651}} . Medecine sciences : M/S.
Adéquation Germany, meeting the needs of scientists in the developing world @article{PMID:17154369,Title={Adéquation Germany, meeting the needs of scientists in the developing world},Author={Chica, Claudia and Jost, Christiane and Féthière, James and Reynaud, Emmanuel G},DOI={10.1002/biot.200690147},Number={12},Volume={1},Month={December},Year={2006},Journal={Biotechnology journal},ISSN={1860-6768},Pages={1347—1350},URL={https://doi.org/10.1002/biot.200690147}} . Biotechnology journal.
Secretory cargo regulates the turnover of COPII subunits at single ER exit sites @article{PMID:16431369,Title={Secretory cargo regulates the turnover of COPII subunits at single ER exit sites},Author={Forster, Rebecca and Weiss, Matthias and Zimmermann, Timo and Reynaud, Emmanuel G and Verissimo, Fatima and Stephens, David J and Pepperkok, Rainer},DOI={10.1016/j.cub.2005.11.076},Number={2},Volume={16},Month={January},Year={2006},Journal={Current biology : CB},ISSN={0960-9822},Pages={173—179},Abstract={The COPII coat complex mediates the formation of transport carriers at specialized sites of the endoplasmic reticulum (ERES). It consists of the Sar1p GTPase and the Sec23/24p and the Sec13/31p subcomplexes . Both stimulate the GTPase activity of Sar1p , which itself triggers coat disassembly. This built-in GAP activity makes the COPII complex in principle unstable and raises the question of how sufficient stability required for cargo capture and carrier formation is achieved. To address this, we analyzed COPII turnover at single ERES in living cells. The half times for Sar1p, Sec23p, and Sec24p turnover are 1.1, 3.7, and 3.9 s, respectively. Decreasing the amount of transport-competent cargo in the endoplasmic reticulum accelerates turnover of the Sec23/24p and slows down that of Sar1p. A mathematical model of COPII membrane turnover that reproduces the experimental in vivo FRAP kinetics and is consistent with existing in vitro data predicts that Sec23/24p remains membrane associated even after GTP hydrolysis by Sar1p for a duration that is strongly increased by the presence of cargo. We conclude that secretory cargo retains the COPII complex on membranes, after Sar1p release has occurred, and prevents premature disassembly of COPII during cargo sorting and transport carrier formation.},URL={https://doi.org/10.1016/j.cub.2005.11.076}} . Current biology : CB.
(2006). Taxonomic colouring of phylogenetic trees of protein sequences . BMC bioinformatics.
(2005). Human Lsg1 defines a family of essential GTPases that correlates with the evolution of compartmentalization . BMC biology.
Scientists for a better world @article{PMID:15689935,Title={Scientists for a better world},Author={Reynaud, Emmanuel G},DOI={10.1038/sj.embor.7400338},Number={2},Volume={6},Month={February},Year={2005},Journal={EMBO reports},ISSN={1469-221X},Pages={103—107},URL={https://europepmc.org/articles/PMC1299248}} . EMBO reports.
In vivo selective cytoskeleton dynamics quantification in interphase cells induced by pulsed ultraviolet laser nanosurgery @article{PMID:16262721,Title={In vivo selective cytoskeleton dynamics quantification in interphase cells induced by pulsed ultraviolet laser nanosurgery},Author={Colombelli, Julien and Reynaud, Emmanuel G and Rietdorf, Jens and Pepperkok, Rainer and Stelzer, Ernst H K},DOI={10.1111/j.1600-0854.2005.00334.x},Number={12},Volume={6},Month={December},Year={2005},Journal={Traffic (Copenhagen, Denmark)},ISSN={1398-9219},Pages={1093—1102},Abstract={We report on the manipulation of intracellular filaments using a nanosurgery system based on a subnanosecond pulsed UV laser optimized for the localized severing of biological polymers. By inducing artificial catastrophe of selected microtubules (MTs), we perform shrinkage-rate measurements in interphase Ptk-2 cells throughout the entire cell. We quantify the impact of two labeling methods and three fluorescent markers, showing a 25% faster depolymerization with Alexa-488 tubulin compared with Rhodamine and yellow fluorescent protein (YFP) tubulins and a 20% higher variability induced by microinjection compared with stable transfection. Using EB3-GFP as a tip marker, we establish a new protocol to measure shrinkage rate, growth rate and rescue frequency simultaneously with high temporal and spatial specificity in live cells. As our analysis shows, laser-induced MT dynamics are physiologically relevant. The high statistical efficiency that the method offers in terms of numbers of measured events and therefore reduced standard deviations represents an important quantitative improvement in the measurement of dynamic instability parameters in vivo. We extend the application of the method by demonstrating induced dynamic behavior of actin-stress fibers after severing. This new method enables the quantitative investigation of cytoskeleton dynamics in a local confinement.},URL={https://doi.org/10.1111/j.1600-0854.2005.00334.x}} . Traffic (Copenhagen, Denmark).
Navigating the secretory pathway: conference on exocytosis membrane structure and dynamics @article{PMID:12223463,Title={Navigating the secretory pathway: conference on exocytosis membrane structure and dynamics},Author={Reynaud, Emmanuel G and Simpson, Jeremy C},DOI={10.1093/embo-reports/kvf185},Number={9},Volume={3},Month={September},Year={2002},Journal={EMBO reports},ISSN={1469-221X},Pages={828—833},URL={https://europepmc.org/articles/PMC1084238}} . EMBO reports.
p57(Kip2) stabilizes the MyoD protein by inhibiting cyclin E-Cdk2 kinase activity in growing myoblasts @article{PMID:10523650,Title={p57(Kip2) stabilizes the MyoD protein by inhibiting cyclin E-Cdk2 kinase activity in growing myoblasts},Author={Reynaud, EG and Pelpel, K and Guillier, M and Leibovitch, MP and Leibovitch, SA},DOI={10.1128/mcb.19.11.7621},Number={11},Volume={19},Month={November},Year={1999},Journal={Molecular and cellular biology},ISSN={0270-7306},Pages={7621—7629},Abstract={We show that expression of p57(Kip2), a potent tight-binding inhibitor of several G(1) cyclin-cyclin-dependent kinase (Cdk) complexes, increases markedly during C2C12 myoblast differentiation. We examined the effect of p57(Kip2) on the activity of the transcription factor MyoD. In transient transfection assays, transcriptional transactivation of the mouse muscle creatine kinase promoter by MyoD was enhanced by the Cdk inhibitors. In addition, p57(Kip2), p21(Cip1), and p27(Kip1) but not p16(Ink4a) induced an increased level of MyoD protein, and we show that MyoD, an unstable nuclear protein, was stabilized by p57(Kip2). Forced expression of p57(Kip2) correlated with hypophosphorylation of MyoD in C2C12 myoblasts. A dominant-negative Cdk2 mutant arrested cells at the G(1) phase transition and induced hypophosphorylation of MyoD. Furthermore, phosphorylation of MyoD by purified cyclin E-Cdk2 complexes was inhibited by p57(Kip2). In addition, the NH2 domain of p57(Kip2) necessary for inhibition of cyclin E-Cdk2 activity was sufficient to inhibit MyoD phosphorylation and to stabilize it, leading to its accumulation in proliferative myoblasts. Taken together, our data suggest that repression of cyclin E-Cdk2-mediated phosphorylation of MyoD by p57(Kip2) could play an important role in the accumulation of MyoD at the onset of myoblast differentiation.},URL={https://europepmc.org/articles/PMC84790}} . Molecular and cellular biology.
PREPRINT
Emmanuel Reynaud, Andrea Souza, Matthew Parnell, Brian J. Rodriguez (2023). Role of pH and Crosslinking Ions on Cell Viability and Metabolic Activity in Alginate-gelatin 3D Prints .
Andrea Souza, Kevin McCarthy, Brian Joseph Rodriguez, Emmanuel G. REYNAUD (2023). The Use of Fluid-phase 3D Printing to Pattern Alginate-gelatin Hydrogel Properties to Guide Cell Growth and Behaviour In Vitro .
Emmanuel G. Reynaud, Luis Gutierrez-Heredia, Amy Garbett, Esben Horn, Jens Carlsson, Patrick C. Collins (2023). Rise of the Cybercrabs: how digital cloning in an integrated taxonomic framework can support deep-sea exploration .
George O. T. Merces, Conor Kennedy, Blanca Lenoci, Emmanuel G. Reynaud, Niamh Burke, Mark Pickering (2020). The Incubot: A 3D Printer-Based Microscope for Long-Term Live Cell Imaging within a Tissue Culture Incubator .