Project acronym A-FRO
Project Actively Frozen - contextual modulation of freezing and its neuronal basis
Researcher (PI) Marta de Aragao Pacheco Moita
Host Institution (HI) FUNDACAO D. ANNA SOMMER CHAMPALIMAUD E DR. CARLOS MONTEZ CHAMPALIMAUD
Country Portugal
Call Details Consolidator Grant (CoG), LS5, ERC-2018-COG
Summary When faced with a threat, an animal must decide whether to freeze, reducing its chances of being noticed, or to flee to the safety of a refuge. Animals from fish to primates choose between these two alternatives when confronted by an attacking predator, a choice that largely depends on the context in which the threat occurs. Recent work has made strides identifying the pre-motor circuits, and their inputs, which control freezing behavior in rodents, but how contextual information is integrated to guide this choice is still far from understood. We recently found that fruit flies in response to visual looming stimuli, simulating a large object on collision course, make rapid freeze/flee choices that depend on the social and spatial environment, and the fly’s internal state. Further, identification of looming detector neurons was recently reported and we identified the descending command neurons, DNp09, responsible for freezing in the fly. Knowing the sensory input and descending output for looming-evoked freezing, two environmental factors that modulate its expression, and using a genetically tractable system affording the use of large sample sizes, places us in an unique position to understand how a information about a threat is integrated with cues from the environment to guide the choice of whether to freeze (our goal). To assess how social information impinges on the circuit for freezing, we will examine the sensory inputs and neuromodulators that mediate this process, mapping their connections to DNp09 neurons (Aim 1). We ask whether learning is required for the spatial modulation of freezing, which cues flies are using to discriminate different places and which brain circuits mediate this process (Aim 2). Finally, we will study how activity of DNp09 neurons drives freezing (Aim 3). This project will provide a comprehensive understanding of the mechanism of freezing and its modulation by the environment, from single neurons to behaviour.
Summary
When faced with a threat, an animal must decide whether to freeze, reducing its chances of being noticed, or to flee to the safety of a refuge. Animals from fish to primates choose between these two alternatives when confronted by an attacking predator, a choice that largely depends on the context in which the threat occurs. Recent work has made strides identifying the pre-motor circuits, and their inputs, which control freezing behavior in rodents, but how contextual information is integrated to guide this choice is still far from understood. We recently found that fruit flies in response to visual looming stimuli, simulating a large object on collision course, make rapid freeze/flee choices that depend on the social and spatial environment, and the fly’s internal state. Further, identification of looming detector neurons was recently reported and we identified the descending command neurons, DNp09, responsible for freezing in the fly. Knowing the sensory input and descending output for looming-evoked freezing, two environmental factors that modulate its expression, and using a genetically tractable system affording the use of large sample sizes, places us in an unique position to understand how a information about a threat is integrated with cues from the environment to guide the choice of whether to freeze (our goal). To assess how social information impinges on the circuit for freezing, we will examine the sensory inputs and neuromodulators that mediate this process, mapping their connections to DNp09 neurons (Aim 1). We ask whether learning is required for the spatial modulation of freezing, which cues flies are using to discriminate different places and which brain circuits mediate this process (Aim 2). Finally, we will study how activity of DNp09 neurons drives freezing (Aim 3). This project will provide a comprehensive understanding of the mechanism of freezing and its modulation by the environment, from single neurons to behaviour.
Max ERC Funding
1 969 750 €
Duration
Start date: 2019-02-01, End date: 2024-01-31
Project acronym CentrioleBirthDeath
Project Mechanism of centriole inheritance and maintenance
Researcher (PI) Monica BETTENCOURT CARVALHO DIAS
Host Institution (HI) FUNDACAO CALOUSTE GULBENKIAN
Country Portugal
Call Details Consolidator Grant (CoG), LS3, ERC-2015-CoG
Summary Centrioles assemble centrosomes and cilia/flagella, critical structures for cell division, polarity, motility and signalling, which are often deregulated in human disease. Centriole inheritance, in particular the preservation of their copy number and position in the cell is critical in many eukaryotes. I propose to investigate, in an integrative and quantitative way, how centrioles are formed in the right numbers at the right time and place, and how they are maintained to ensure their function and inheritance. We first ask how centrioles guide their own assembly position and centriole copy number. Our recent work highlighted several properties of the system, including positive and negative feedbacks and spatial cues. We explore critical hypotheses through a combination of biochemistry, quantitative live cell microscopy and computational modelling. We then ask how the centrosome and the cell cycle are both coordinated. We recently identified the triggering event in centriole biogenesis and how its regulation is akin to cell cycle control of DNA replication and centromere assembly. We will explore new hypotheses to understand how assembly time is coupled to the cell cycle. Lastly, we ask how centriole maintenance is regulated. By studying centriole disappearance in the female germline we uncovered that centrioles need to be actively maintained by their surrounding matrix. We propose to investigate how that matrix provides stability to the centrioles, whether this is differently regulated in different cell types and the possible consequences of its misregulation for the organism (infertility and ciliopathy-like symptoms). We will take advantage of several experimental systems (in silico, ex-vivo, flies and human cells), tailoring the assay to the question and allowing for comparisons across experimental systems to provide a deeper understanding of the process and its regulation.
Summary
Centrioles assemble centrosomes and cilia/flagella, critical structures for cell division, polarity, motility and signalling, which are often deregulated in human disease. Centriole inheritance, in particular the preservation of their copy number and position in the cell is critical in many eukaryotes. I propose to investigate, in an integrative and quantitative way, how centrioles are formed in the right numbers at the right time and place, and how they are maintained to ensure their function and inheritance. We first ask how centrioles guide their own assembly position and centriole copy number. Our recent work highlighted several properties of the system, including positive and negative feedbacks and spatial cues. We explore critical hypotheses through a combination of biochemistry, quantitative live cell microscopy and computational modelling. We then ask how the centrosome and the cell cycle are both coordinated. We recently identified the triggering event in centriole biogenesis and how its regulation is akin to cell cycle control of DNA replication and centromere assembly. We will explore new hypotheses to understand how assembly time is coupled to the cell cycle. Lastly, we ask how centriole maintenance is regulated. By studying centriole disappearance in the female germline we uncovered that centrioles need to be actively maintained by their surrounding matrix. We propose to investigate how that matrix provides stability to the centrioles, whether this is differently regulated in different cell types and the possible consequences of its misregulation for the organism (infertility and ciliopathy-like symptoms). We will take advantage of several experimental systems (in silico, ex-vivo, flies and human cells), tailoring the assay to the question and allowing for comparisons across experimental systems to provide a deeper understanding of the process and its regulation.
Max ERC Funding
2 000 000 €
Duration
Start date: 2017-01-01, End date: 2022-12-31
Project acronym CODECHECK
Project CRACKING THE CODE BEHIND MITOTIC FIDELITY: the roles of tubulin post-translational modifications and a chromosome separation checkpoint
Researcher (PI) Helder Jose Martins Maiato
Host Institution (HI) INSTITUTO DE BIOLOGIA MOLECULAR E CELULAR-IBMC
Country Portugal
Call Details Consolidator Grant (CoG), LS3, ERC-2015-CoG
Summary During the human lifetime 10000 trillion cell divisions take place to ensure tissue homeostasis and several vital functions in the organism. Mitosis is the process that ensures that dividing cells preserve the chromosome number of their progenitors, while deviation from this, a condition known as aneuploidy, represents the most common feature in human cancers. Here we will test two original concepts with strong implications for chromosome segregation fidelity. The first concept is based on the “tubulin code” hypothesis, which predicts that molecular motors “read” tubulin post-translational modifications on spindle microtubules. Our proof-of-concept experiments demonstrate that tubulin detyrosination works as a navigation system that guides chromosomes towards the cell equator. Thus, in addition to regulating the motors required for chromosome motion, the cell might regulate the tracks in which they move on. We will combine proteomic, super-resolution and live-cell microscopy, with in vitro reconstitutions, to perform a comprehensive survey of the tubulin code and the respective implications for motors involved in chromosome motion, mitotic spindle assembly and correction of kinetochore-microtubule attachments. The second concept is centered on the recently uncovered chromosome separation checkpoint mediated by a midzone-associated Aurora B gradient, which delays nuclear envelope reformation in response to incompletely separated chromosomes. We aim to identify Aurora B targets involved in the spatiotemporal regulation of the anaphase-telophase transition. We will establish powerful live-cell microscopy assays and a novel mammalian model system to dissect how this checkpoint allows the detection and correction of lagging/long chromosomes and DNA bridges that would otherwise contribute to genomic instability. Overall, this work will establish a paradigm shift in our understanding of how spatial information is conveyed to faithfully segregate chromosomes during mitosis.
Summary
During the human lifetime 10000 trillion cell divisions take place to ensure tissue homeostasis and several vital functions in the organism. Mitosis is the process that ensures that dividing cells preserve the chromosome number of their progenitors, while deviation from this, a condition known as aneuploidy, represents the most common feature in human cancers. Here we will test two original concepts with strong implications for chromosome segregation fidelity. The first concept is based on the “tubulin code” hypothesis, which predicts that molecular motors “read” tubulin post-translational modifications on spindle microtubules. Our proof-of-concept experiments demonstrate that tubulin detyrosination works as a navigation system that guides chromosomes towards the cell equator. Thus, in addition to regulating the motors required for chromosome motion, the cell might regulate the tracks in which they move on. We will combine proteomic, super-resolution and live-cell microscopy, with in vitro reconstitutions, to perform a comprehensive survey of the tubulin code and the respective implications for motors involved in chromosome motion, mitotic spindle assembly and correction of kinetochore-microtubule attachments. The second concept is centered on the recently uncovered chromosome separation checkpoint mediated by a midzone-associated Aurora B gradient, which delays nuclear envelope reformation in response to incompletely separated chromosomes. We aim to identify Aurora B targets involved in the spatiotemporal regulation of the anaphase-telophase transition. We will establish powerful live-cell microscopy assays and a novel mammalian model system to dissect how this checkpoint allows the detection and correction of lagging/long chromosomes and DNA bridges that would otherwise contribute to genomic instability. Overall, this work will establish a paradigm shift in our understanding of how spatial information is conveyed to faithfully segregate chromosomes during mitosis.
Max ERC Funding
2 323 468 €
Duration
Start date: 2016-07-01, End date: 2021-06-30
Project acronym makingtheretina
Project Principles of retinal neuronal lamination from zebrafish to humans
Researcher (PI) Caren NORDEN
Host Institution (HI) FUNDACAO CALOUSTE GULBENKIAN
Country Portugal
Call Details Consolidator Grant (CoG), LS5, ERC-2018-COG
Summary Neuronal lamination is a hallmark of many diverse brain areas where it is important for efficient circuit formation and neuronal wiring. Despite this significance, the cellular and tissue scale principles that ensure successful and robust lamination are not fully understood. In particular, how cell-tissue interactions and biomechanics influence neuronal lamination is only scarcely explored. To fill this gap, we will use the vertebrate retina with its five neuronal cell types arranged in a highly ordered pattern to investigate the emergence of neuronal lamination.
We will initially use the zebrafish system and employ long term light sheet imaging to reveal the migration behaviour of the different retinal neurons. Based on this, transcriptomics approaches will enable the dissection of cellular pathways and extracellular cues involved in neuronal migration and overall lamination. To dissect how biomechanics influence lamination, we will use Brillouin microscopy to explore the influence of changing tissue stiffness on lamination and test the role of differential adhesion. These combined results will be the basis to expand studies to the human system and ex vivo human organoids to generate insights into human retinal development.
To date, systematic studies investigating molecular pathways in combination with biophysical parameters to understand brain formation across model systems are rare. Due to our previous expertise, we are in an excellent position to perform such interdisciplinary, integrative and interspecies approach. This will unveil common denominators of retinal neuronal lamination in zebrafish, humans and human organoids and thereby reveal the similarities of retinal development in different species and how developmental programs compare in vivo versus ex vivo.
In addition, while this proposal focuses on neural lamination in the retina, findings will also inspire future cross-disciplinary studies investigating neuronal lamination in other parts of the brain.
Summary
Neuronal lamination is a hallmark of many diverse brain areas where it is important for efficient circuit formation and neuronal wiring. Despite this significance, the cellular and tissue scale principles that ensure successful and robust lamination are not fully understood. In particular, how cell-tissue interactions and biomechanics influence neuronal lamination is only scarcely explored. To fill this gap, we will use the vertebrate retina with its five neuronal cell types arranged in a highly ordered pattern to investigate the emergence of neuronal lamination.
We will initially use the zebrafish system and employ long term light sheet imaging to reveal the migration behaviour of the different retinal neurons. Based on this, transcriptomics approaches will enable the dissection of cellular pathways and extracellular cues involved in neuronal migration and overall lamination. To dissect how biomechanics influence lamination, we will use Brillouin microscopy to explore the influence of changing tissue stiffness on lamination and test the role of differential adhesion. These combined results will be the basis to expand studies to the human system and ex vivo human organoids to generate insights into human retinal development.
To date, systematic studies investigating molecular pathways in combination with biophysical parameters to understand brain formation across model systems are rare. Due to our previous expertise, we are in an excellent position to perform such interdisciplinary, integrative and interspecies approach. This will unveil common denominators of retinal neuronal lamination in zebrafish, humans and human organoids and thereby reveal the similarities of retinal development in different species and how developmental programs compare in vivo versus ex vivo.
In addition, while this proposal focuses on neural lamination in the retina, findings will also inspire future cross-disciplinary studies investigating neuronal lamination in other parts of the brain.
Max ERC Funding
1 923 750 €
Duration
Start date: 2019-10-01, End date: 2024-09-30
Project acronym VINCULUM
Project Entailing Perpetuity: Family, Power, Identity. The Social Agency of a Corporate Body (Southern Europe, 14th-17th Centuries)
Researcher (PI) Maria de Lurdes Pereira ROSA
Host Institution (HI) UNIVERSIDADE NOVA DE LISBOA
Country Portugal
Call Details Consolidator Grant (CoG), SH6, ERC-2018-COG
Summary Few legal phenomena have been so relevant to premodern southern Europe societies as entails, a specific strategy that evolved to protect family inheritances, thus enabling the reproduction of elite social status. The VINCULUM project aims to explain how entailment became possible, how it functioned, and why it lasted for so many centuries. The project rests on the innovative theoretical claim that entails, as corporate bodies, functioned as a key social agent, created and acting within societies for which non-personal legal subjects were normal. Building on the Portuguese-Iberian case, and on the extensive research already carried out by me and my team, I propose to study 'entailment' as a diverse but pivotal practice, one embedded in law, aristocratic discourse, and kinship-based organization, and to carry out comprehensive analysis that explores this global nature. The research approach systematically breaks with traditional research frontiers: cases will extend from the 14th to 17th century in both continental and Atlantic spaces, and include both comparative perspectives and the study of later social reconfigurations.
VINCULUM will be anchored in extended research in public archives and on unprecedented access to extensive private family archives, which have been opened to research by the ARQFAM program I have led since 2008. Data collection will allow for the construction of a large database, gathering all documents relating to each entail, under a theoretical model that seeks to reconstruct past information systems, thus testing a novel methodology developed in my previous research. The database that will gather c.7000 entails, enabling systematic inquiries organized around the new conceptual definitions proposed by the project. The research will be strongly interdisciplinary, engaging with historical anthropology and archival science in order to construct a proper theoretical model for understanding this crucial legal and social phenomenon.
Summary
Few legal phenomena have been so relevant to premodern southern Europe societies as entails, a specific strategy that evolved to protect family inheritances, thus enabling the reproduction of elite social status. The VINCULUM project aims to explain how entailment became possible, how it functioned, and why it lasted for so many centuries. The project rests on the innovative theoretical claim that entails, as corporate bodies, functioned as a key social agent, created and acting within societies for which non-personal legal subjects were normal. Building on the Portuguese-Iberian case, and on the extensive research already carried out by me and my team, I propose to study 'entailment' as a diverse but pivotal practice, one embedded in law, aristocratic discourse, and kinship-based organization, and to carry out comprehensive analysis that explores this global nature. The research approach systematically breaks with traditional research frontiers: cases will extend from the 14th to 17th century in both continental and Atlantic spaces, and include both comparative perspectives and the study of later social reconfigurations.
VINCULUM will be anchored in extended research in public archives and on unprecedented access to extensive private family archives, which have been opened to research by the ARQFAM program I have led since 2008. Data collection will allow for the construction of a large database, gathering all documents relating to each entail, under a theoretical model that seeks to reconstruct past information systems, thus testing a novel methodology developed in my previous research. The database that will gather c.7000 entails, enabling systematic inquiries organized around the new conceptual definitions proposed by the project. The research will be strongly interdisciplinary, engaging with historical anthropology and archival science in order to construct a proper theoretical model for understanding this crucial legal and social phenomenon.
Max ERC Funding
1 591 450 €
Duration
Start date: 2019-06-01, End date: 2024-11-30
