Essential physiological functions, including cell division, cell adhesion and motility, and tissue morphogenesis, rely on the capacity of animal cells to change and adapt their shape. To accomplish these force-dependent tasks, animal cells make use of actin cytoskeletal filaments. The precise way in which actin filaments organize, i.e. how actin filaments are physically oriented in space, and how filament organization is remodeled in time, is determinant for force generation. Being able to measure actin filament organization directly in living cells and tissues thus promises to advance our understanding of how proteins and signaling pathways individually and collectively control actin-driven cellular functions. We will present the development of novel genetically-encoded, green- and red-fluorescent-protein-based reporters that allow non-invasive, quantitative measurements of actin filament organization in living cells and tissues by using polarization-resolved fluorescence microscopy. We will show examples of actin organization measurements in living mammalian cells in culture, as well as in living Drosophila and C.elegans embryos, and fission yeast cells.

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A critical step in embryonic development is the allocation of progenitors at the site of differentiation. By combining in vivo imaging and biomechanical manipulation in zebrafish embryos, we reveal a mechanism of progenitor cell allocation mediated by mechanical forces that derives from an incomplete process of epithelial delamination. Progenitors of the zebrafish laterality organ undergo a delamination process and retain long-lasting apical contacts that allow the epithelial layer to pull and direct them to the site of differentiation. This mechanical tissue-tissue coupling provides leader cell properties to a subset of progenitors that subsequently guide the directed movement of other progenitors, which behave as followers, ensuring the allocation of the entire progenitor pool at the site of organ differentiation, while protecting them from unwanted loss. Thus, we reveal that incomplete delamination serves as a cellular platform for coordinated tissue movements during development.

Lumen formation is a fundamental principle of morphogenesis. The first lumen in mammalian development appears at the end of preimplantation development, when the embryo forms the blastocyst. Blastocyst lumen formation occurs in an intricate process in which cell contacts are broken to form hundreds of micron-sized lumens, which then exchange fluid until one final lumen remains. The cellular processes underlying this process remain incompletely understood.

In my talk, I will present the previously undescribed phenomenon of inverse blebs during blastocyst formation. Inverse blebs are short-lived membrane protrusions into the cytosol at cell-cell contacts with a lifetime of ca. 1 min. They form due to intercellular fluid pressure and retract in an actomyosin-dependent manner. During my talk, I will describe inverse bleb dynamics and the mechanism of their formation and retraction. I will also explain how inverse blebs relate to the overall lumen formation process and how they might ensure the robust formation of a single final lumen.

This exciting talk will kick-off the monthly "Tissue Mechanics Group Meeting" (TMGM) that will take place one Friday per month at 4pm. The idea behind these meetings is to provide an informal forum for people to present their work (unpublished and ongoing) to a community of people at Curie interested in tissue mechanics at multiple scales. This informal setting will facilitate discussion and connections between researchers with similar interested and varied expertise. The talks willbe followed by a "happy hour" to enable further discussions!

U900 Unit is happy to announce the creation of a new seminar entitled "A Spatial Transcriptomics Odyssey". The scope of this seminar is to share how people working with spatial transcriptomics data are navigating them, from technological advances to the developpement of computational tools, as well as to exchange news in the field through a journal club. It thus encourages researchers from different teams to come and share their work and their questions but also receive valuable input from pairs working with similar problematics.

And coming soon :

The seminar will take place physically at Institute Curie Paris. We encourage you to come onsite to have an interactive discussion but visioconference will be considered if needed.

The seminar will take place physically at Institute Curie Paris. We encourage you to come onsite to have an interactive discussion but visioconference will be available if needed.

If you are interested to attend, present or have any remark, please feel free to fill this poll : https://forms.office.com/r/1KagFEVaxb

or contact the organizators lucie.gaspard-boulinc@curie.fr , loic.chadoutaud@curie.fr & thomas.defard@curie.fr.

DNA is often referred to as the instruction book of life. No matter how much we agree, it nevertheless contains the description of the coding genes and a multiplicity of regulatory elements, from transcription factors to miRNAs. Furthermore, deep learning techniques have been developed and improved in recent years, from convolutional networks to recurrent and long short-term memory networks. The revolution in Neural Language Processing consisted of injecting the attention mechanisms in networks leading to more powerful transformer architectures.

These network types have proven to be particularly helpful for many tasks: DNA-protein binding prediction, methylcytosine prediction, non-coding-function prediction, enhancer identification, DNABERT, and AlfaFold.

The talk will focus on gene expression prediction from the DNA sequences, oncogenic probability prediction of gene fusion alterations, and Sars-Cov-19 variant identification from the Spike gene sequence.

Assessing protein organization and dynamics in their native cellular context provides invaluable insights into their activities and functions. Fluorescence microscopy has drastically improved and diversified over the last 20 years, allowing major discoveries in cell biology, neuroscience and developmental biology. It is today possible to monitor the evolution of fluorescent markers over a period of time ranging between milliseconds up to several days with down to single molecule spatial resolution, in very diverse living biological systems ranging from single cells up to whole embryos. However, depending on the biological question, one usually requires to use several, expensive and often very sophisticated imaging techniques.

I will present the capabilities and requirements of the soSPIM (single-objective Selective Plane Illumination Microscopy) imaging technique to: i) probe the 3D nanoscale organization of proteins in depth at the single-molecule level, and ii) achieve quantitative high-content imaging of living and fixed 3D cell-cultures (spheroids/organoids) with unprecedented throughput. soSPIM is a light-sheet microscopy technique operating on a standard mono-objective inverted microscope. It relies on dedicated microchips embedding arrays of microwells flanked with 45° micro-mirrors acting as light guides and culture vessels.

[1] Galland et al., 3D high- and super-resolution imaging using single-objective SPIM, Nat Methods, 12 (2015) 641-644.
[2] Singh et al., 3D Protein Dynamics in the Cell Nucleus. Biophys J. 2017.
[3] Beghin et al., Automated high-speed 3D imaging of organoid cultures with multi-scale phenotypic quantification. Nat Methods. 2022.

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http://igfl.ens-lyon.fr/equipes/f.-leulier-functional-genomics-of-host-intestinal-bacteria-interactions

Strong evidence is now available about the damages produced by the underestimation of gender and sex variables, ranging from low quality research, inefficacy of new drugs, inaccu-rate or late diagnosis, waste of resources and investments, and preventable deaths and pain. A lot of scientific evidence shows important aspects of this phenomenon:

Conversely, scientific literature increasingly shows the benefits deriving from the inclusion of sex and gender variables in the prevention, diagnosis and cure of an enlarging set of pathologies including cancer.

I will discuss the importance of the sex and gender dimension in science and medicine.

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Séminaire proposé par Marine Poupon,
Chargée de communication

Le but du programme est de fournir aux participants une vision complète des concepts, paradigmes et technologies de la biologie du développement moderne en accordant une attention particulière aux cellules souches. La formation abordera le développement normal et anormal à travers une variété de systèmes modèles embryonnaires en s’appuyant sur les méthodologies les plus récentes.

Le programme est proposé en 2 versions avec deux dates limites d'inscription pour chaque version:

Version longue (3,5 semaines: cours practiques at Sorbonne Université & Seminaires à l'Institut Curie) : 31 Juillet

Version Courte (10 jours, séminaires à  l'Institut Curie) : 11 septembre

There is no life without lipids. Lipids are essential for cell-environment interactions, cellular organization, and could have been instrumental in the emergence of life itself. Despite significant evolutionary divergence in the molecular composition of biological membranes, all known life forms converge on a single strategy for building responsive interfaces – the lipid membrane. Although a membrane can be assembled from only one type of lipid, biological membranes are built from a staggering diversity of lipid species. Why have cells evolved to make membranes that are so diverse? In this talk I will introduce two approaches to study how life employs the emergent properties of lipids to build responsive organizational interfaces between cells and their environment. First, we have developed the Minimal Cell (JCVI-Syn3B) and its pathogenic parent organism Mycoplasma mycoides as experimental platforms in which lipidome size can be manipulated. By tuning lipidome size from fewer than 10 to more than 100 lipid species we are beginning to decipher the role of lipidome complexity for cellular fitness in the context of a changing environment. Second, we are studying how two of the most ancient biomolecules on Earth, RNA and lipids, can selectively interact to form responsive systems. Our observations reveal a functional interaction between RNA and lipids, providing a simple answer to a fundamental question in the debate on the origin of life – how could primordial RNA molecules be regulated?

TEMTIA est un congrès international réunissant 200 à 250 scientifiques du monde entier. Cette année, le congrès fête ses 10 ans et, pour la 1ère fois, il se déroulera en France, à l'Institut Curie.

Historiquement, ces colloques sont dédiés aux aspects moléculaires et cellulaires de la transition épithélio-mésenchymateuse (EMT), dans les contextes du développement embryonnaire et de la progression tumorale. Ils sont caractérisés par une très forte pluridisciplinarité et par une collégialité illustrée notamment par la rédaction récente d'un article collectif de revue dans Nature Reviews Molecular Cell Biology (Yang et al 2020). Au cours des années, le programme de ces colloques s'est enrichi pour intégrer la notion de plasticité cellulaire, avec des composantes cellules souches, résistance au traitement, régulation de l'intégrité génomique et de l'apoptose selon les contextes. Ils réunissent tous les contributeurs importants du domaine, tout en conservant une politique de renouvellement des intervenants.