Project acronym 0MSPIN
Project Spintronics based on relativistic phenomena in systems with zero magnetic moment
Researcher (PI) Tomá Jungwirth
Host Institution (HI) FYZIKALNI USTAV AV CR V.V.I
Call Details Advanced Grant (AdG), PE3, ERC-2010-AdG_20100224
Summary The 0MSPIN project consists of an extensive integrated theoretical, experimental and device development programme of research opening a radical new approach to spintronics. Spintronics has the potential to supersede existing storage and memory applications, and to provide alternatives to current CMOS technology. Ferromagnetic matels used in all current spintronics applications may make it impractical to realise the full potential of spintronics. Metals are unsuitable for transistor and information processing applications, for opto-electronics, or for high-density integration. The 0MSPIN project aims to remove the major road-block holding back the development of spintronics in a radical way: removing the ferromagnetic component from key active parts or from the whole of the spintronic devices. This approach is based on exploiting the combination of exchange and spin-orbit coupling phenomena and material systems with zero macroscopic moment. The goal of the 0MSPIN is to provide a new paradigm by which spintronics can enter the realms of conventional semiconductors in both fundamental condensed matter research and in information technologies. In the central part of the proposal, the research towards this goal is embedded within a materials science project whose aim is to introduce into physics and microelectronics an entirely new class of semiconductors. 0MSPIN seeks to exploit three classes of material systems: (1) Antiferromagnetic bi-metallic 3d-5d alloys (e.g. Mn2Au). (2) Antiferromagnetic I-II-V semiconductors (e.g. LiMnAs). (3) Non-magnetic spin-orbit coupled semiconductors with injected spin-polarized currents (e.g. 2D III-V structures). Proof of concept devices operating at high temperatures will be fabricated to show-case new functionalities offered by zero-moment systems for sensing and memory applications, information processing, and opto-electronics technologies.
Summary
The 0MSPIN project consists of an extensive integrated theoretical, experimental and device development programme of research opening a radical new approach to spintronics. Spintronics has the potential to supersede existing storage and memory applications, and to provide alternatives to current CMOS technology. Ferromagnetic matels used in all current spintronics applications may make it impractical to realise the full potential of spintronics. Metals are unsuitable for transistor and information processing applications, for opto-electronics, or for high-density integration. The 0MSPIN project aims to remove the major road-block holding back the development of spintronics in a radical way: removing the ferromagnetic component from key active parts or from the whole of the spintronic devices. This approach is based on exploiting the combination of exchange and spin-orbit coupling phenomena and material systems with zero macroscopic moment. The goal of the 0MSPIN is to provide a new paradigm by which spintronics can enter the realms of conventional semiconductors in both fundamental condensed matter research and in information technologies. In the central part of the proposal, the research towards this goal is embedded within a materials science project whose aim is to introduce into physics and microelectronics an entirely new class of semiconductors. 0MSPIN seeks to exploit three classes of material systems: (1) Antiferromagnetic bi-metallic 3d-5d alloys (e.g. Mn2Au). (2) Antiferromagnetic I-II-V semiconductors (e.g. LiMnAs). (3) Non-magnetic spin-orbit coupled semiconductors with injected spin-polarized currents (e.g. 2D III-V structures). Proof of concept devices operating at high temperatures will be fabricated to show-case new functionalities offered by zero-moment systems for sensing and memory applications, information processing, and opto-electronics technologies.
Max ERC Funding
1 938 000 €
Duration
Start date: 2011-06-01, End date: 2016-05-31
Project acronym 1D-Engine
Project 1D-electrons coupled to dissipation: a novel approach for understanding and engineering superconducting materials and devices
Researcher (PI) Adrian KANTIAN
Host Institution (HI) UPPSALA UNIVERSITET
Call Details Starting Grant (StG), PE3, ERC-2017-STG
Summary Correlated electrons are at the forefront of condensed matter theory. Interacting quasi-1D electrons have seen vast progress in analytical and numerical theory, and thus in fundamental understanding and quantitative prediction. Yet, in the 1D limit fluctuations preclude important technological use, particularly of superconductors. In contrast, high-Tc superconductors in 2D/3D are not precluded by fluctuations, but lack a fundamental theory, making prediction and engineering of their properties, a major goal in physics, very difficult. This project aims to combine the advantages of both areas by making major progress in the theory of quasi-1D electrons coupled to an electron bath, in part building on recent breakthroughs (with the PIs extensive involvement) in simulating 1D and 2D electrons with parallelized density matrix renormalization group (pDMRG) numerics. Such theory will fundamentally advance the study of open electron systems, and show how to use 1D materials as elements of new superconducting (SC) devices and materials: 1) It will enable a new state of matter, 1D electrons with true SC order. Fluctuations from the electronic liquid, such as graphene, could also enable nanoscale wires to appear SC at high temperatures. 2) A new approach for the deliberate engineering of a high-Tc superconductor. In 1D, how electrons pair by repulsive interactions is understood and can be predicted. Stabilization by reservoir - formed by a parallel array of many such 1D systems - offers a superconductor for which all factors setting Tc are known and can be optimized. 3) Many existing superconductors with repulsive electron pairing, all presently not understood, can be cast as 1D electrons coupled to a bath. Developing chain-DMFT theory based on pDMRG will allow these materials SC properties to be simulated and understood for the first time. 4) The insights gained will be translated to 2D superconductors to study how they could be enhanced by contact with electronic liquids.
Summary
Correlated electrons are at the forefront of condensed matter theory. Interacting quasi-1D electrons have seen vast progress in analytical and numerical theory, and thus in fundamental understanding and quantitative prediction. Yet, in the 1D limit fluctuations preclude important technological use, particularly of superconductors. In contrast, high-Tc superconductors in 2D/3D are not precluded by fluctuations, but lack a fundamental theory, making prediction and engineering of their properties, a major goal in physics, very difficult. This project aims to combine the advantages of both areas by making major progress in the theory of quasi-1D electrons coupled to an electron bath, in part building on recent breakthroughs (with the PIs extensive involvement) in simulating 1D and 2D electrons with parallelized density matrix renormalization group (pDMRG) numerics. Such theory will fundamentally advance the study of open electron systems, and show how to use 1D materials as elements of new superconducting (SC) devices and materials: 1) It will enable a new state of matter, 1D electrons with true SC order. Fluctuations from the electronic liquid, such as graphene, could also enable nanoscale wires to appear SC at high temperatures. 2) A new approach for the deliberate engineering of a high-Tc superconductor. In 1D, how electrons pair by repulsive interactions is understood and can be predicted. Stabilization by reservoir - formed by a parallel array of many such 1D systems - offers a superconductor for which all factors setting Tc are known and can be optimized. 3) Many existing superconductors with repulsive electron pairing, all presently not understood, can be cast as 1D electrons coupled to a bath. Developing chain-DMFT theory based on pDMRG will allow these materials SC properties to be simulated and understood for the first time. 4) The insights gained will be translated to 2D superconductors to study how they could be enhanced by contact with electronic liquids.
Max ERC Funding
1 491 013 €
Duration
Start date: 2018-10-01, End date: 2024-03-31
Project acronym 2D-TOPSENSE
Project Tunable optoelectronic devices by strain engineering of 2D semiconductors
Researcher (PI) Andres CASTELLANOS
Host Institution (HI) AGENCIA ESTATAL CONSEJO SUPERIOR DEINVESTIGACIONES CIENTIFICAS
Call Details Starting Grant (StG), PE7, ERC-2017-STG
Summary The goal of 2D-TOPSENSE is to exploit the remarkable stretchability of two-dimensional semiconductors to fabricate optoelectronic devices where strain is used as an external knob to tune their properties.
While bulk semiconductors tend to break under strains larger than 1.5%, 2D semiconductors (such as MoS2) can withstand deformations of up to 10-20% before rupture. This large breaking strength promises a great potential of 2D semiconductors as ‘straintronic’ materials, whose properties can be adjusted by applying a deformation to their lattice. In fact, recent theoretical works predicted an interesting physical phenomenon: a tensile strain-induced semiconductor-to-metal transition in 2D semiconductors. By tensioning single-layer MoS2 from 0% up to 10%, its electronic band structure is expected to undergo a continuous transition from a wide direct band-gap of 1.8 eV to a metallic behavior. This unprecedented large strain-tunability will undoubtedly have a strong impact in a wide range of optoelectronic applications such as photodetectors whose cut-off wavelength is tuned by varying the applied strain or atomically thin light modulators.
To date, experimental works on strain engineering have been mostly focused on fundamental studies, demonstrating part of the potential of 2D semiconductors in straintronics, but they have failed to exploit strain engineering to add extra functionalities to optoelectronic devices. In 2D-TOPSENSE I will go beyond the state of the art in straintronics by designing and fabricating optoelectronic devices whose properties and performance can be tuned by means of applying strain. 2D-TOPSENSE will focus on photodetectors with a tunable bandwidth and detectivity, light emitting devices whose emission wavelength can be adjusted, light modulators based on 2D semiconductors such as transition metal dichalcogenides or black phosphorus and solar funnels capable of directing the photogenerated charge carriers towards a specific position.
Summary
The goal of 2D-TOPSENSE is to exploit the remarkable stretchability of two-dimensional semiconductors to fabricate optoelectronic devices where strain is used as an external knob to tune their properties.
While bulk semiconductors tend to break under strains larger than 1.5%, 2D semiconductors (such as MoS2) can withstand deformations of up to 10-20% before rupture. This large breaking strength promises a great potential of 2D semiconductors as ‘straintronic’ materials, whose properties can be adjusted by applying a deformation to their lattice. In fact, recent theoretical works predicted an interesting physical phenomenon: a tensile strain-induced semiconductor-to-metal transition in 2D semiconductors. By tensioning single-layer MoS2 from 0% up to 10%, its electronic band structure is expected to undergo a continuous transition from a wide direct band-gap of 1.8 eV to a metallic behavior. This unprecedented large strain-tunability will undoubtedly have a strong impact in a wide range of optoelectronic applications such as photodetectors whose cut-off wavelength is tuned by varying the applied strain or atomically thin light modulators.
To date, experimental works on strain engineering have been mostly focused on fundamental studies, demonstrating part of the potential of 2D semiconductors in straintronics, but they have failed to exploit strain engineering to add extra functionalities to optoelectronic devices. In 2D-TOPSENSE I will go beyond the state of the art in straintronics by designing and fabricating optoelectronic devices whose properties and performance can be tuned by means of applying strain. 2D-TOPSENSE will focus on photodetectors with a tunable bandwidth and detectivity, light emitting devices whose emission wavelength can be adjusted, light modulators based on 2D semiconductors such as transition metal dichalcogenides or black phosphorus and solar funnels capable of directing the photogenerated charge carriers towards a specific position.
Max ERC Funding
1 930 437 €
Duration
Start date: 2018-03-01, End date: 2023-02-28
Project acronym 2DHIBSA
Project Nanoscopic and Hierachical Materials via Living Crystallization-Driven Self-Assembly
Researcher (PI) Ian MANNERS
Host Institution (HI) UNIVERSITY OF BRISTOL
Call Details Advanced Grant (AdG), PE5, ERC-2017-ADG
Summary A key synthetic challenge of widespread interest in chemical science involves the creation of well-defined 2D functional materials that exist on a length-scale of nanometers to microns. In this ambitious 5 year proposal we aim to tackle this issue by exploiting the unique opportunities made possible by recent developments with the living crystallization-driven self-assembly (CDSA) platform. Using this solution processing approach, amphiphilic block copolymers (BCPs) with crystallizable blocks, related amphiphiles, and polymers with charged end groups will be used to predictably construct monodisperse samples of tailored, functional soft matter-based 2D nanostructures with controlled shape, size, and spatially-defined chemistries. Many of the resulting nanostructures will also offer unprecedented opportunities as precursors to materials with hierarchical structures through further solution-based “bottom-up” assembly methods. In addition to fundamental studies, the proposed work also aims to make important impact in the cutting-edge fields of liquid crystals, interface stabilization, catalysis, supramolecular polymers, and hierarchical materials.
Summary
A key synthetic challenge of widespread interest in chemical science involves the creation of well-defined 2D functional materials that exist on a length-scale of nanometers to microns. In this ambitious 5 year proposal we aim to tackle this issue by exploiting the unique opportunities made possible by recent developments with the living crystallization-driven self-assembly (CDSA) platform. Using this solution processing approach, amphiphilic block copolymers (BCPs) with crystallizable blocks, related amphiphiles, and polymers with charged end groups will be used to predictably construct monodisperse samples of tailored, functional soft matter-based 2D nanostructures with controlled shape, size, and spatially-defined chemistries. Many of the resulting nanostructures will also offer unprecedented opportunities as precursors to materials with hierarchical structures through further solution-based “bottom-up” assembly methods. In addition to fundamental studies, the proposed work also aims to make important impact in the cutting-edge fields of liquid crystals, interface stabilization, catalysis, supramolecular polymers, and hierarchical materials.
Max ERC Funding
2 499 597 €
Duration
Start date: 2018-05-01, End date: 2023-04-30
Project acronym 2DTHERMS
Project Design of new thermoelectric devices based on layered and field modulated nanostructures of strongly correlated electron systems
Researcher (PI) Jose Francisco Rivadulla Fernandez
Host Institution (HI) UNIVERSIDAD DE SANTIAGO DE COMPOSTELA
Call Details Starting Grant (StG), PE3, ERC-2010-StG_20091028
Summary Design of new thermoelectric devices based on layered and field modulated nanostructures of strongly correlated electron systems
Summary
Design of new thermoelectric devices based on layered and field modulated nanostructures of strongly correlated electron systems
Max ERC Funding
1 427 190 €
Duration
Start date: 2010-11-01, End date: 2015-10-31
Project acronym 3-TOP
Project Exploring the physics of 3-dimensional topological insulators
Researcher (PI) Laurens Wigbolt Molenkamp
Host Institution (HI) JULIUS-MAXIMILIANS-UNIVERSITAT WURZBURG
Call Details Advanced Grant (AdG), PE3, ERC-2010-AdG_20100224
Summary Topological insulators constitute a novel class of materials where the topological details of the bulk band structure induce a robust surface state on the edges of the material. While transport data for 2-dimensional topological insulators have recently become available, experiments on their 3-dimensional counterparts are mainly limited to photoelectron spectroscopy. At the same time, a plethora of interesting novel physical phenomena have been predicted to occur in such systems.
In this proposal, we sketch an approach to tackle the transport and magnetic properties of the surface states in these materials. This starts with high quality layer growth, using molecular beam epitaxy, of bulk layers of HgTe, Bi2Se3 and Bi2Te3, which are the prime candidates to show the novel physics expected in this field. The existence of the relevant surface states will be assessed spectroscopically, but from there on research will focus on fabricating and characterizing nanostructures designed to elucidate the transport and magnetic properties of the topological surfaces using electrical, optical and scanning probe techniques. Apart from a general characterization of the Dirac band structure of the surface states, research will focus on the predicted magnetic monopole-like response of the system to an electrical test charge. In addition, much effort will be devoted to contacting the surface state with superconducting and magnetic top layers, with the final aim of demonstrating Majorana fermion behavior. As a final benefit, growth of thin high quality thin Bi2Se3 or Bi2Te3 layers could allow for a demonstration of the (2-dimensional) quantum spin Hall effect at room temperature - offering a road map to dissipation-less transport for the semiconductor industry.
Summary
Topological insulators constitute a novel class of materials where the topological details of the bulk band structure induce a robust surface state on the edges of the material. While transport data for 2-dimensional topological insulators have recently become available, experiments on their 3-dimensional counterparts are mainly limited to photoelectron spectroscopy. At the same time, a plethora of interesting novel physical phenomena have been predicted to occur in such systems.
In this proposal, we sketch an approach to tackle the transport and magnetic properties of the surface states in these materials. This starts with high quality layer growth, using molecular beam epitaxy, of bulk layers of HgTe, Bi2Se3 and Bi2Te3, which are the prime candidates to show the novel physics expected in this field. The existence of the relevant surface states will be assessed spectroscopically, but from there on research will focus on fabricating and characterizing nanostructures designed to elucidate the transport and magnetic properties of the topological surfaces using electrical, optical and scanning probe techniques. Apart from a general characterization of the Dirac band structure of the surface states, research will focus on the predicted magnetic monopole-like response of the system to an electrical test charge. In addition, much effort will be devoted to contacting the surface state with superconducting and magnetic top layers, with the final aim of demonstrating Majorana fermion behavior. As a final benefit, growth of thin high quality thin Bi2Se3 or Bi2Te3 layers could allow for a demonstration of the (2-dimensional) quantum spin Hall effect at room temperature - offering a road map to dissipation-less transport for the semiconductor industry.
Max ERC Funding
2 419 590 €
Duration
Start date: 2011-04-01, End date: 2016-03-31
Project acronym 3CBIOTECH
Project Cold Carbon Catabolism of Microbial Communities underprinning a Sustainable Bioenergy and Biorefinery Economy
Researcher (PI) Gavin James Collins
Host Institution (HI) NATIONAL UNIVERSITY OF IRELAND GALWAY
Call Details Starting Grant (StG), LS9, ERC-2010-StG_20091118
Summary The applicant will collaborate with Irish, European and U.S.-based colleagues to develop a sustainable biorefinery and bioenergy industry in Ireland and Europe. The focus of this ERC Starting Grant will be the application of classical microbiological, physiological and real-time polymerase chain reaction (PCR)-based assays, to qualitatively and quantitatively characterize microbial communities underpinning novel and innovative, low-temperature, anaerobic waste (and other biomass) conversion technologies, including municipal wastewater treatment and, demonstration- and full-scale biorefinery applications.
Anaerobic digestion (AD) is a naturally-occurring process, which is widely applied for the conversion of waste to methane-containing biogas. Low-temperature (<20 degrees C) AD has been applied by the applicant as a cost-effective alternative to mesophilic (c. 35C) AD for the treatment of several waste categories. However, the microbiology of low-temperature AD is poorly understood. The applicant will work with microbial consortia isolated from anaerobic bioreactors, which have been operated for long-term experiments (>3.5 years), and include organic acid-oxidizing, hydrogen-producing syntrophic microbes and hydrogen-consuming methanogens. A major focus of the project will be the ecophysiology of psychrotolerant and psychrophilic methanogens already identified and cultivated by the applicant. The project will also investigate the role(s) of poorly-understood Crenarchaeota populations and homoacetogenic bacteria, in complex consortia. The host organization is a leading player in the microbiology of waste-to-energy applications. The applicant will train a team of scientists in all aspects of the microbiology and bioengineering of biomass conversion systems.
Summary
The applicant will collaborate with Irish, European and U.S.-based colleagues to develop a sustainable biorefinery and bioenergy industry in Ireland and Europe. The focus of this ERC Starting Grant will be the application of classical microbiological, physiological and real-time polymerase chain reaction (PCR)-based assays, to qualitatively and quantitatively characterize microbial communities underpinning novel and innovative, low-temperature, anaerobic waste (and other biomass) conversion technologies, including municipal wastewater treatment and, demonstration- and full-scale biorefinery applications.
Anaerobic digestion (AD) is a naturally-occurring process, which is widely applied for the conversion of waste to methane-containing biogas. Low-temperature (<20 degrees C) AD has been applied by the applicant as a cost-effective alternative to mesophilic (c. 35C) AD for the treatment of several waste categories. However, the microbiology of low-temperature AD is poorly understood. The applicant will work with microbial consortia isolated from anaerobic bioreactors, which have been operated for long-term experiments (>3.5 years), and include organic acid-oxidizing, hydrogen-producing syntrophic microbes and hydrogen-consuming methanogens. A major focus of the project will be the ecophysiology of psychrotolerant and psychrophilic methanogens already identified and cultivated by the applicant. The project will also investigate the role(s) of poorly-understood Crenarchaeota populations and homoacetogenic bacteria, in complex consortia. The host organization is a leading player in the microbiology of waste-to-energy applications. The applicant will train a team of scientists in all aspects of the microbiology and bioengineering of biomass conversion systems.
Max ERC Funding
1 499 797 €
Duration
Start date: 2011-05-01, End date: 2016-04-30
Project acronym 3D-CAP
Project 3D micro-supercapacitors for embedded electronics
Researcher (PI) David Sarinn PECH
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Consolidator Grant (CoG), PE7, ERC-2017-COG
Summary The realization of high-performance micro-supercapacitors is currently a big challenge but the ineluctable applications requiring such miniaturized energy storage devices are continuously emerging, from wearable electronic gadgets to wireless sensor networks. Although they store less energy than micro-batteries, micro-supercapacitors can be charged and discharged very rapidly and exhibit a quasi-unlimited lifetime. The global scientific research is consequently largely focused on the improvement of their capacitance and energetic performances. However, to date, they are still far from being able to power sensors or electronic components.
Here I propose a 3D paradigm shift of micro-supercapacitor design to ensure increased energy storage capacities. Hydrous ruthenium dioxide (RuO2) is a pseudocapacitive material for supercapacitor electrode well-known for its high capacitance. A thin-film of ruthenium will be deposited by atomic layer deposition (ALD), followed by an electrochemical oxidation process, onto a high-surface-area 3D current collector prepared via an ingenious dynamic template built with hydrogen bubbles. The structural features of these 3D architectures will be controllably tailored by the processing methodologies. These electrodes will be combined with an innovative electrolyte in solid form (a protic ionogel) able to operate over an extended cell voltage. In a parallel investigation, we will develop a fundamental understanding of electrochemical reactions occurring at the nanoscale with a FIB-patterned (Focused Ion Beam) RuO2 nano-supercapacitor. The resulting 3D micro-supercapacitors should display extremely high power, long lifetime and – for the first time – energy densities competing or even exceeding that of micro-batteries. As a key achievement, prototypes will be designed using a new concept based on a self-adaptative micro-supercapacitors matrix, which arranges itself according to the global amount of energy stored.
Summary
The realization of high-performance micro-supercapacitors is currently a big challenge but the ineluctable applications requiring such miniaturized energy storage devices are continuously emerging, from wearable electronic gadgets to wireless sensor networks. Although they store less energy than micro-batteries, micro-supercapacitors can be charged and discharged very rapidly and exhibit a quasi-unlimited lifetime. The global scientific research is consequently largely focused on the improvement of their capacitance and energetic performances. However, to date, they are still far from being able to power sensors or electronic components.
Here I propose a 3D paradigm shift of micro-supercapacitor design to ensure increased energy storage capacities. Hydrous ruthenium dioxide (RuO2) is a pseudocapacitive material for supercapacitor electrode well-known for its high capacitance. A thin-film of ruthenium will be deposited by atomic layer deposition (ALD), followed by an electrochemical oxidation process, onto a high-surface-area 3D current collector prepared via an ingenious dynamic template built with hydrogen bubbles. The structural features of these 3D architectures will be controllably tailored by the processing methodologies. These electrodes will be combined with an innovative electrolyte in solid form (a protic ionogel) able to operate over an extended cell voltage. In a parallel investigation, we will develop a fundamental understanding of electrochemical reactions occurring at the nanoscale with a FIB-patterned (Focused Ion Beam) RuO2 nano-supercapacitor. The resulting 3D micro-supercapacitors should display extremely high power, long lifetime and – for the first time – energy densities competing or even exceeding that of micro-batteries. As a key achievement, prototypes will be designed using a new concept based on a self-adaptative micro-supercapacitors matrix, which arranges itself according to the global amount of energy stored.
Max ERC Funding
1 673 438 €
Duration
Start date: 2018-04-01, End date: 2023-03-31
Project acronym 3DCellPhase-
Project In situ Structural Analysis of Molecular Crowding and Phase Separation
Researcher (PI) Julia MAHAMID
Host Institution (HI) EUROPEAN MOLECULAR BIOLOGY LABORATORY
Call Details Starting Grant (StG), LS1, ERC-2017-STG
Summary This proposal brings together two fields in biology, namely the emerging field of phase-separated assemblies in cell biology and state-of-the-art cellular cryo-electron tomography, to advance our understanding on a fundamental, yet illusive, question: the molecular organization of the cytoplasm.
Eukaryotes organize their biochemical reactions into functionally distinct compartments. Intriguingly, many, if not most, cellular compartments are not membrane enclosed. Rather, they assemble dynamically by phase separation, typically triggered upon a specific event. Despite significant progress on reconstituting such liquid-like assemblies in vitro, we lack information as to whether these compartments in vivo are indeed amorphous liquids, or whether they exhibit structural features such as gels or fibers. My recent work on sample preparation of cells for cryo-electron tomography, including cryo-focused ion beam thinning, guided by 3D correlative fluorescence microscopy, shows that we can now prepare site-specific ‘electron-transparent windows’ in suitable eukaryotic systems, which allow direct examination of structural features of cellular compartments in their cellular context. Here, we will use these techniques to elucidate the structural principles and cytoplasmic environment driving the dynamic assembly of two phase-separated compartments: Stress granules, which are RNA bodies that form rapidly in the cytoplasm upon cellular stress, and centrosomes, which are sites of microtubule nucleation. We will combine these studies with a quantitative description of the crowded nature of cytoplasm and of its local variations, to provide a direct readout of the impact of excluded volume on molecular assembly in living cells. Taken together, these studies will provide fundamental insights into the structural basis by which cells form biochemical compartments.
Summary
This proposal brings together two fields in biology, namely the emerging field of phase-separated assemblies in cell biology and state-of-the-art cellular cryo-electron tomography, to advance our understanding on a fundamental, yet illusive, question: the molecular organization of the cytoplasm.
Eukaryotes organize their biochemical reactions into functionally distinct compartments. Intriguingly, many, if not most, cellular compartments are not membrane enclosed. Rather, they assemble dynamically by phase separation, typically triggered upon a specific event. Despite significant progress on reconstituting such liquid-like assemblies in vitro, we lack information as to whether these compartments in vivo are indeed amorphous liquids, or whether they exhibit structural features such as gels or fibers. My recent work on sample preparation of cells for cryo-electron tomography, including cryo-focused ion beam thinning, guided by 3D correlative fluorescence microscopy, shows that we can now prepare site-specific ‘electron-transparent windows’ in suitable eukaryotic systems, which allow direct examination of structural features of cellular compartments in their cellular context. Here, we will use these techniques to elucidate the structural principles and cytoplasmic environment driving the dynamic assembly of two phase-separated compartments: Stress granules, which are RNA bodies that form rapidly in the cytoplasm upon cellular stress, and centrosomes, which are sites of microtubule nucleation. We will combine these studies with a quantitative description of the crowded nature of cytoplasm and of its local variations, to provide a direct readout of the impact of excluded volume on molecular assembly in living cells. Taken together, these studies will provide fundamental insights into the structural basis by which cells form biochemical compartments.
Max ERC Funding
1 228 125 €
Duration
Start date: 2018-02-01, End date: 2023-01-31
Project acronym 3DEpi
Project Transgenerational epigenetic inheritance of chromatin states : the role of Polycomb and 3D chromosome architecture
Researcher (PI) Giacomo CAVALLI
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Advanced Grant (AdG), LS2, ERC-2017-ADG
Summary Epigenetic inheritance entails transmission of phenotypic traits not encoded in the DNA sequence and, in the most extreme case, Transgenerational Epigenetic Inheritance (TEI) involves transmission of memory through multiple generations. Very little is known on the mechanisms governing TEI and this is the subject of the present proposal. By transiently enhancing long-range chromatin interactions, we recently established isogenic Drosophila epilines that carry stable alternative epialleles, defined by differential levels of the Polycomb-dependent H3K27me3 mark. Furthermore, we extended our paradigm to natural phenotypes. These are ideal systems to study the role of Polycomb group (PcG) proteins and other components in regulating nuclear organization and epigenetic inheritance of chromatin states. The present project conjugates genetics, epigenomics, imaging and molecular biology to reach three critical aims.
Aim 1: Analysis of the molecular mechanisms regulating Polycomb-mediated TEI. We will identify the DNA, protein and RNA components that trigger and maintain transgenerational chromatin inheritance as well as their mechanisms of action.
Aim 2: Role of 3D genome organization in the regulation of TEI. We will analyze the developmental dynamics of TEI-inducing long-range chromatin interactions, identify chromatin components mediating 3D chromatin contacts and characterize their function in the TEI process.
Aim 3: Identification of a broader role of TEI during development. TEI might reflect a normal role of PcG components in the transmission of parental chromatin onto the next embryonic generation. We will explore this possibility by establishing other TEI paradigms and by relating TEI to the normal PcG function in these systems and in normal development.
This research program will unravel the biological significance and the molecular underpinnings of TEI and lead the way towards establishing this area of research into a consolidated scientific discipline.
Summary
Epigenetic inheritance entails transmission of phenotypic traits not encoded in the DNA sequence and, in the most extreme case, Transgenerational Epigenetic Inheritance (TEI) involves transmission of memory through multiple generations. Very little is known on the mechanisms governing TEI and this is the subject of the present proposal. By transiently enhancing long-range chromatin interactions, we recently established isogenic Drosophila epilines that carry stable alternative epialleles, defined by differential levels of the Polycomb-dependent H3K27me3 mark. Furthermore, we extended our paradigm to natural phenotypes. These are ideal systems to study the role of Polycomb group (PcG) proteins and other components in regulating nuclear organization and epigenetic inheritance of chromatin states. The present project conjugates genetics, epigenomics, imaging and molecular biology to reach three critical aims.
Aim 1: Analysis of the molecular mechanisms regulating Polycomb-mediated TEI. We will identify the DNA, protein and RNA components that trigger and maintain transgenerational chromatin inheritance as well as their mechanisms of action.
Aim 2: Role of 3D genome organization in the regulation of TEI. We will analyze the developmental dynamics of TEI-inducing long-range chromatin interactions, identify chromatin components mediating 3D chromatin contacts and characterize their function in the TEI process.
Aim 3: Identification of a broader role of TEI during development. TEI might reflect a normal role of PcG components in the transmission of parental chromatin onto the next embryonic generation. We will explore this possibility by establishing other TEI paradigms and by relating TEI to the normal PcG function in these systems and in normal development.
This research program will unravel the biological significance and the molecular underpinnings of TEI and lead the way towards establishing this area of research into a consolidated scientific discipline.
Max ERC Funding
2 500 000 €
Duration
Start date: 2018-11-01, End date: 2023-10-31
