CRG Scientific Sessions

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.

Host: Garrido Enamorado, Romina

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.

Host: Bartomeus Cistaré, Magalí

Host: Lehner, Ben

Host: Garrido Enamorado, Romina

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.

Host: Serrano Pubul, Luis

Host: Francesc Posas (UPF)

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.

Host: Berta Alsina (UPF)

Host: Salvador Aznar-Benitah (CRG)

Host: Fátima Gebauer (CRG)

Host: Estivill, Xavier

Host: Davide D'Amico (CRG)

Host: Fernando Giráldez (UPF)

Host: Graf, Thomas

Host: Matthieu Louis (CRG)

Host: Louis, Matthieu

Host: Anna Bigas (IMIM)

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.

Host: Francesc Posas (UPF)

Host: José Yélamos

Host: Joaquim Gea (IMIM)

Host: Fernando Giráldez (UPF)

Host: Matthieu Louis (CRG)

Host: Inmaculada Hernández Muńoz (IMIM)

Host: Fátima Gebauer (CRG)

Host: Mark Isalan (CRG)