Systems Biology Programme Jeremy Green Department of Craniofacial Development, King's College London, UK "Measuring growth, patterning and morphogenesis in oral epithelia"
Host: Jäger, Yogi
Abstract: The oral palate an approximately rectilinear piece of anatomy that provides an excellent model system for the analysis and modelling of growth and patterning. Moreover, the proper morphogenesis of the oral palate, as with other parts of the orofacial complex, is critical for health. The palate is made as two shelves which grow towards the midline as shelves from the upper jaw (maxilla) eventually fusing to form the roof of the mouth. Transverse ridges, or rugae, are useful ruler-like landmarks for measurement of growth and patterning of the palatal shelves and are prefigured by stripes of Sonic Hedgehog (Shh) expression. We analysed the successive appearance of Shh stripes, characterised a growth zone and found perturbation responses both in mutants and in explants in vitro that are signatures of a two-morphogen Turing-type reaction-diffusion patterning mechanism. We have further identified FGF and Shh as an activator and inhibitor in this system, possibly the first confirmed Turing morphogen pair for a mammalian striped pattern in vivo. Surprisingly, we found that the growth zone does not correspond to a high proliferation zone. To explain the growth distribution, we have developed tools for quantitative mapping of cell shape and packing and measured local proliferation and cell division orientation. Integrating the cellular measures with gross tissue growth will enable a high-resolution phenotypic atlas as a critical baseline for the interpretation of genetic perturbations and a cellular understanding of normal morphogenetic mechanism.
Reference: Economou, AD, Ohazama, A, Porntaveetus T, Sharpe PT, Kondo S, Basson MA, Gritli-Linde A, Cobourne MT & Green JBA (2012) Periodic stripe formation by a Turing-mechanism operating at growth zones in the mammalian palate. Nature Genetics 44(3):348-51.
Cell and Developmental Biology Programme Mohan Gupta Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago (IL) US "Regulation of anaphase spindle function by the microtubule motor Kinesin-8"
Host: Chaves Simoes de Carvalho, Pedro Nuno
Abstract: Microtubules are essential cytoskeletal filaments that fill cellular roles such as providing structure and organization, pushing or pulling objects, or providing tracks for intracellular transport. Microtubules are intrinsically dynamic polymers, however, defining the mechanisms that spatially and temporally regulate microtubule dynamics during diverse processes is a central challenge to understanding cytoskeletal function. Kinesin-8 is a conserved family of microtubule motor protein with important roles in chromosome alignment and spindle function in a wide range of organisms. We found that the budding yeast, Saccharomyces cerevisiae, Kinesin-8 functions to actively restrain inappropriate spindle elongation during anaphase. When cells were challenged with an anaphase arrest, spindles stopped elongating when they obtained a length approximately equal to the cell diameter. However, in the absence of Kinesin-8, spindles failed to stop elongating, buckled, and continued to hyper-elongate, obtaining more than two-fold the length of the cell. Our results also reveal that similar mechanisms drive typical anaphase elongation and hyper-elongation, and, that polymerization of midzone microtubules is tightly coupled to anti-parallel microtubule sliding and spindle elongation. Together, these results demonstrate that budding yeast Kinesin-8 plays a novel role at the midzone to restrain hyper-elongation and maintain spindle integrity, and support a model in which the microtubule regulating activity of Kinesin-8 is a key input controlling spindle length.
Systems Biology Programme Naomi Habib Interdisciplinary Program in Computer Science and Computational Biology, Hebrew University of Jerusalem A functional selection model explains evolutionary robustness despite plasticity in regulatory networks
PRBB-CRG Sessions Dunkan Odom Regulatory Systems Biology Laboratory, Cancer Research UK Cambridge Research Institute, Cambridge UK "Mechanisms and Evolution of Mammalian Transcriptional Regulation"
Host: Salvador Aznar-Benitah (CRG)
Abstract:
Duncan Odom will be presenting recent results from his lab that explore how transcriptional regulation and genome architecture evolve among mammals. CTCF binding, RNA polymerases, and transcription factor binding have all shown surprises in how, where, and why they are conserved, and his talk will encompass many recent published and unpublished observations.
Systems Biology Programme Nevan Krogan Department of Cellular and Molecular Pharmacology, University of California, San Francisco (CA) US "to be determined"
PRBB-CRG Sessions Carsten Janke Department of Signalling, Neurobiology and Cancer, Institut Curie, Orsay Cedex FR "Regulation of microtubule functions by posttranslational modifications"
Host: Isabelle Vernos (CRG)
Abstract: Microtubules are the core components of the eukaryotic cytoskeleton, and play an important role in a large range of cellular functions, such as intracellular organisation, cell migration, cell division, neuronal differentiation and function, as well as assembly and function of cilia, flagella and centrosomes. Due to their highly dynamic structure and the large variety of microtubule associated proteins (MAPs) and molecular motors, microtubules are able to rapidly change their functions in a temporarily and locally restricted manner. One of the potential mechanisms to regulate microtubule dynamics and functions are the posttranslational modifications of tubulin. I will present the identification of the enzymes that generate and remove two tubulin modifications, polyglutamylation and polyglycylation, as well as first functional studies that have shed light onto the role of these modifications in the regulation of the microtubule cytoskeleton. Our data indicate that polyglutamylation and polyglycylation play essential roles in the assembly, function and maintenance of cilia, flagella and neurons.
PRBB-CRG Sessions Sylvie Schneider-Maunoury Vertebrate brain morphogenesis, INSERM; Developmental Biology Laboratory (LBD), CNRS, Université Pierre et Marie Curie, Paris FR "to be determined"
PRBB-CRG Sessions Valentina Greco Department of Genetics, Yale University School of Medicine and Yale Stem Cell Center, New Haven (CT) US "to be determined"
Gene Regulation,Stem Cells&Cancer Progr. Vania Broccoli Stem cells and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan IT "Somatic cell reprogramming into dopaminergic neurons for Parkinson's disease therapy"
PRBB-CRG Sessions L. Mahadevan Engineering and Applied Sciences, Organismic and Evolutionary Biology, Wyss Institute, Kavli Institute, Harvard University, Cambridge (MA) US "to be determined"
Systems Biology Programme Marta Zlatic and Albert Cardona Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn (VA) US "Structure and function of somatosensory circuitry in Drosophila larva"
PRBB-CRG Sessions Florian Engert Department of Molecular and Cellular Biology, Harvard University, Cambridge (MA) US "Sensory processing and motor control in larval zebrafish"
Host: Andreas Braun (CRG)
Abstract: A fundamental question in neuroscience is how neural circuits generate behavior and adapt it to changes in sensory feedback. Here we use two-photon calcium imaging throughout the brain of larval zebrafish while the paralyzed animals interact fictively with a virtual environment and rapidly adapt their motor output to changes in visual feedback. We describe the neural dynamics that occur during adaptive locomotion throughout the brain of the fish, and provide an anatomical map of their locations. A subset of these signals occurred during behavioral adjustments and are attractive candidates for the functional elements that drive motor learning. This work enables us to propose a specific model of a neural circuit that detects mismatches between expected and actual feed-back and adjusts the sensory motor transformation accordingly.
PRBB-CRG Sessions Haruo Saito Division of Molecular Cell Signaling, Institute of Medical Sciences, The University of Tokyo, Tokyo JP "to be determined"
PRBB-CRG Sessions Alberto J. L. Macario Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore, USA "to be determined"