ERC FUNDED PROJECTS

The deep-sea floor hosts a distinct microbial biome covering 67% of the Earth’s surface, characterized by cold temperatures, permanent darkness, high pressure and food limitation. The surface sediments are dominated by bacteria, with on average a billion cells per ml. Benthic bacteria are highly relevant to the Earth’s element cycles as they remineralize most of the organic matter sinking from the productive surface ocean, and return nutrients, thereby promoting ocean primary production. What passes the bacterial filter is a relevant sink for carbon on geological time scales, influencing global oxygen and carbon budgets, and fueling the deep subsurface biosphere. Despite the relevance of deep-sea sediment bacteria to climate, geochemical cycles and ecology of the seafloor, their genetic and functional diversity, niche differentiation and biological interactions remain unknown. Our preliminary work in a global survey of deep-sea sediments enables us now to target specific genes for the quantification of abyssal bacteria. We can trace isotope-labeled elements into communities and single cells, and analyze the molecular alteration of organic matter during microbial degradation, all in context with environmental dynamics recorded at the only long-term deep-sea ecosystem observatory in the Arctic that we maintain. I propose to bridge biogeochemistry, ecology, microbiology and marine biology to develop a systematic understanding of abyssal sediment bacterial community distribution, diversity, function and interactions, by combining in situ flux studies and different visualization techniques with a wide range of molecular tools. Substantial progress is expected in understanding I) identity and function of the dominant types of indigenous benthic bacteria, II) dynamics in bacterial activity and diversity caused by variations in particle flux, III) interactions with different types and ages of organic matter, and other biological factors.

3 375 693 €

Start date: 2012-06-01, End date: 2018-05-31

The cell cortex is a highly dynamic layer of crosslinked actin filaments and myosin molecular motors beneath the cell membrane. It plays a central role in large scale rearrangements that occur inside cells. Many molecular mechanisms contribute to cortex structure and dynamics. However, cell scale physical properties of the cortex are difficult to grasp. This is problematic because for large scale rearrangements inside a cell, such as coherent flow of the cell cortex, it is the cell scale emergent properties that are important for the realization of such events. I will investigate how the actomyosin cytoskeleton behaves at a coarse grained and cellular scale, and will study how this emergent active behaviour is influenced by molecular mechanisms. We will study the cell cortex in the one cell stage C. elegans embryo, which undergoes large scale cortical flow during polarization and cytokinesis. We will combine theory and experiment. We will characterize cortex structure and dynamics with biophysical techniques such as cortical laser ablation and quantitative photobleaching experiments. We will develop and employ novel theoretical approaches to describe the cell scale mechanical behaviour in terms of an active complex fluid. We will utilize genetic approaches to understand how these emergent mechanical properties are influenced by molecular activities. A central goal is to arrive at a coarse grained description of the cortex that can predict future dynamic behaviour from the past structure, which is conceptually similar to how weather forecasting is accomplished. To date, systematic approaches to link molecular scale physical mechanisms to those on cellular scales are missing. This work will open new opportunities for cell biological and cell biophysical research, by providing a methodological approach for bridging scales, for studying emergent and large-scale active mechanical behaviours and linking them to molecular mechanisms.

1 500 000 €

Start date: 2011-12-01, End date: 2017-08-31

1.2 billion people worldwide lack access to safe drinking water. Drinking water quality is threatened by newly emerging organic micro-pollutants (pesticides, pharmaceuticals, industrial chemicals) in source waters. Nanofiltration is a technology that is expected to play a key role in future water treatment processes due to its effectiveness in removal of micropollutants. However, the loss of membrane flux due to fouling is one of the main impediments in the development of membrane processes for use in drinking water treatment. Currently there is a wholly inadequate mechanistic understanding of the role of biofilm on the fouling of nanofiltration membranes. Applying techniques including confocal microscopy, force spectroscopy, and infrared spectroscopy using an experimental programme informed by a technique known as scale-down together with mathematical modelling, it is confidently expected that significant advances will be gained in the mechanistic understanding of nanofiltration biofouling. The specific objectives are 1. How is the rate of formation and extent of such biofilms influenced by the biological response to the local microenvironment? 2 Elucidate the effect of extracellular polysaccharide substances on physical properties, composition and structure of these biofilms. 3: Investigate mechanisms to enhance biofilm removal by a physical detachment process complemented by techniques that alter biofilm material properties. A more fundamental insight into the mechanisms of nanofiltration operation will help in further development of this treatment method in future water treatment processes.

1 468 987 €

Start date: 2011-10-01, End date: 2016-09-30

"Nanomaterials such as carbon nanotubes or graphene sheets represent the future of material science, due to their potentially exceptional mechanical properties. One great drawback of all artificial materials, however, is the decrease of strength with increasing toughness, and viceversa. This problem is not encountered in many biological nanomaterials (e.g. spider silk, bone, nacre). Other biological materials display exceptional adhesion or damping properties, and can be self-cleaning or self-healing. The “secret” of biomaterials seems to lie in “hierarchy”: several levels can often be identified (2 in nacre, up to 7 in bone and dentine), from nano- to micro-scale. The idea of this project is to combine Nature and Nanotechnology to design hierarchical composites with tailor made characteristics, optimized with respect to both strength and toughness, as well as materials with strong adhesion/easy detachment, smart damping, self-healing/-cleaning properties or controlled energy dissipation. For example, one possible objective is to design the “world’s toughest composite material”. The potential impact and importance of these goals on materials science, the high-tech industry and ultimately the quality of human life could be considerable. In order to tackle such a challenging design process, the PI proposes to adopt ultimate nanomechanics theoretical tools corroborated by continuum or atomistic simulations, multi-scale numerical parametric simulations and Finite Element optimization procedures, starting from characterization experiments on biological- or nano-materials, from the macroscale to the nanoscale. Results from theoretical, numerical and experimental work packages will be applied to a specific case study in an engineering field of particular interest to demonstrate importance and feasibility, e.g. an airplane wing with a considerably enhanced fatigue resistance and reduced ice-layer adhesion, leading to a 10 fold reduction in wasted fuel."

1 004 400 €

Start date: 2012-01-01, End date: 2016-12-31

"Tissue engineering (TE), the interdisciplinary field combining biomedical and engineering sciences in the search for functional man-made organ replacements, has key issues with the quantity and quality of the generated products. Protocols followed in the lab are mainly trial and error based, requiring a huge amount of manual interventions and lacking clear early time-point quality criteria to guide the process. As a result, these processes are very hard to scale up to industrial production levels. BRIDGE aims to fortify the engineering aspects of the TE field by adding a higher level of understanding and control to the manufacturing process (MP) through the use of in silico models. BRIDGE will focus on the bone TE field to provide proof of concept for its in silico approach. The combination of the applicant's well-received published and ongoing work on a wide range of modelling tools in the bone field combined with the state-of-the-art experimental techniques present in the TE lab of the additional participant allows envisaging following innovation and impact: 1. proof-of-concept of the use of an in silico blue-print for the design and control of a robust modular TE MP; 2. model-derived optimised culture conditions for patient derived cell populations increasing modular robustness of in vitro chondrogenesis/endochondral ossification; 3. in silico identification of a limited set of in vitro biomarkers that is predictive of the in vivo outcome; 4. model-derived optimised culture conditions increasing quantity and quality of the in vivo outcome of the TE MP; 5. incorporation of congenital defects in the in silico MP design, constituting a further validation of BRIDGE’s in silico approach and a necessary step towards personalised medical care. We believe that the systematic – and unprecedented – integration of (bone) TE and mathematical modelling, as proposed in BRIDGE, is required to come to a rationalized, engineering approach to design and control bone TE MPs."

1 191 440 €

Start date: 2011-12-01, End date: 2016-11-30

Cardiovascular disease keeps the top spot in mortality statistics in Europe with 2 million deaths annually and although prevention and therapy have continuously been improved, the prevalence of heart failure continues to rise. While contractile (systolic) dysfunction is readily accessible to pharmacological treatment, there is a lack of therapeutic options for reduced ventricular filling (diastolic dysfunction). The diastolic properties of the heart are largely determined by the giant sarcomeric protein titin, which is alternatively spliced to adjust the elastic properties of the cardiomyocyte. We have recently identified a titin splice factor that plays a parallel role in cardiac disease and postnatal development. It targets a subset of genes that concertedly affect biomechanics, electrical activity, and signal transduction and suggests alternative splicing as a novel therapeutic target in heart disease. Here we will build on the titin splice factor to identify regulatory principles and cofactors that adjust cardiac isoform expression. In a complementary approach we will investigate titin mRNA binding proteins to provide a comprehensive analysis of factors governing titin’s differential splicing in cardiac development, health, and disease. Based on its distinctive role in ventricular filling we will evaluate titin splicing as a therapeutic target in diastolic heart failure and use a titin based reporter assay to identify small molecules to interfere with titin isoform expression. Finally, we will evaluate the effects of altered alternative splicing on diastolic dysfunction in vivo utilizing the splice deficient mutant and our available animal models for diastolic dysfunction. The overall scientific goal of the proposed work is to investigate the regulation of cardiac alternative splicing in development and disease and to evaluate if splice directed therapy can be used to improve diastolic function and specifically the elastic properties of the heart.

1 499 191 €

Start date: 2012-01-01, End date: 2017-06-30

Timing is everything in ecology, and because plants provide the foundation for most land-based food webs, the timing of their activities profoundly orchestrates the majority of ecological interactions. Most photosynthetic and growth processes are under circadian control, but many additional processes--approximately 30-40% of all genes—are under circadian control, and yet the Darwinian fitness impact of being “in synch” with the environment has not been systematically studied for any organism. We have developed a toolbox for a native tobacco plant, Nicotiana attenuata, that allows us to “ask the plant” which genes, proteins or metabolites are regulated in particular plant-mediated ecological interactions; identify “the genes that matter” for a given interaction; silence or ectopically express these genes, and conduct field releases with the transformed plants at a nature preserve in the Great Basin Desert to rigorously test hypotheses of gene function. By taking advantage of both our understanding of what it takes for this plant to survive in nature, and the procedures established to disentangle the skein of subtle interactions that determine its performance, we will systematically examine the importance of synchronous entrained endogenous rhythms at all life stages: longevity in the seed bank, germination, rosette growth, elongation, flowering and senescence. Specifically, we propose to silence a key components (starting with NaTOC1) of the plant’s endogenous clock to shorten the plant’s circadian rhythm, both constitutively and with strong dexamethasone-inducible promoters, at all life stages. With a combination of real-time phenotype imaging, metabolite and transcriptome analysis, and ecological know-how, the research will reveal how plants adjust their physiologies to the ever-changing panoply of environmental stresses with which they must cope; by creating arrhythmic plants, we will understand why so many processes are under circadian control.

2 496 002 €

Start date: 2012-04-01, End date: 2017-03-31

The vast majority of genetic diseases are complex traits, conditioned by multiple genetic and environmental factors. Yet our understanding of the genetics underlying such traits in humans remains extremely limited, due largely to the statistical complexity of inferring the effects of allelic variants in a genetically diverse population. Novel tools for the dissection of the genetic architecture of complex traits, therefore, can be most effectively developed in model organisms, where the contribution of individual alleles can be quantitatively determined in controlled genetic backgrounds. We have previously established the yeast Saccharomyces cerevisiae as a model for complex traits by unravelling complex genetic architectures that govern quantitative phenotypes in this organism. We achieved this by pioneering approaches that have revealed crucial information about the complexity of the underlying genetics. Here we propose to advance to the next level of complex trait dissection by developing systematic, genome-wide technologies that aim to identify all of the variants underlying a complex trait in a single step. In particular, we will investigate traits involved in mitochondrial function, which are both clinically relevant and highly conserved in yeast. Our combination of genomic technologies will allow us to: 1) systematically detect, with maximal sensitivity, the majority of genetic variants (coding and non-coding) that condition these traits; 2) quantify the contributions of these variants and their interactions; and 3) evaluate the strengths and limitations of current methods for dissecting complex traits. Taken together, our research will yield fundamental insights into the genetic complexity of multifactorial traits, providing valuable lessons and establishing novel genomic tools that will facilitate the investigation of complex diseases.

2 499 821 €

Start date: 2012-11-01, End date: 2017-10-31

Our sensory systems gather stimuli as elemental physical features yet we perceive a world made up of familiar objects, not wavelengths or vibrations. Perception occurs when the neuronal representation of physical parameters is transformed into the neuronal representation of meaningful objects. How does this recoding occur? An ideal platform for the inquiry is the rat whisker sensory system: it produces fast and accurate judgments of complex stimuli, yet can be broken down into accessible neuronal mechanisms. CONCEPT will examine the process that begins with whisker motion and ends with perception of the contacted object. Understanding the general principles for the construction of perception will help explain why we experience the world as we do. The main hypothesis is that graded neuronal representations at early processing stages are “fractured” to generate discrete object representations at late processing stages. Of particular interest is the emergence of object representations as the meaning of new stimuli is acquired. We will collect multi-site single-unit and local field potential signals simultaneously with precise behavioral indices, and will interpret data through advanced computational methods. We will begin by quantifying whisker motion as rats discriminate texture, thus defining the raw material on which the brain operates. Next, we will characterize the transformation of texture along an intracortical stream from sensory areas (where we expect that neurons encode whisker kinematics) to frontal and rhinal areas (where we expect that neurons encode objects extracted from the graded physical continuum) and hippocampus (where we expect that neurons encode objects in conjunction with context). We will test candidate processing schemes by manipulating perception on single trials using optogenetic methods.

2 500 000 €

Start date: 2012-06-01, End date: 2018-05-31