ERC FUNDED PROJECTS

Polar materials, such as piezoelectrics and ferroelectrics are essential to our modern life, yet they are mostly developed by trial-and-error. Their properties overwhelmingly depend on the defects within them, the majority of which are hidden in the bulk. The road to better materials is via mapping these defects, but our best tool for it – piezoresponse force microscopy (PFM) – is limited to surfaces. 3D-PXM aims to revolutionize our understanding by measuring the local structure-property correlations around individual defects buried deep in the bulk. This is a completely new kind of microscopy enabling 3D maps of local strain and polarization (i.e. piezoresponse) with 10 nm resolution in mm-sized samples. It is novel, multi-scale and fast enough to capture defect dynamics in real time. Uniquely, it is a full-field method that uses a synthetic-aperture approach to improve both resolution and recover the image phase. This phase is then quantitatively correlated to local polarization and strain via a forward model. 3D-PXM combines advances in X-Ray optics, phase recovery and data analysis to create something transformative. In principle, it can achieve spatial resolution comparable to the best coherent X-Ray microscopy methods while being faster, used on larger samples, and without risk of radiation damage. For the first time, this opens the door to solving how defects influence bulk properties under real-life conditions. 3D-PXM focuses on three types of defects prevalent in polar materials: grain boundaries, dislocations and polar nanoregions. Individually they address major gaps in the state-of-the-art, while together making great strides towards fully understanding defects. This understanding is expected to inform a new generation of multi-scale models that can account for a material’s full heterogeneity. These models are the first step towards abandoning our tradition of trial-and-error, and with this comes the potential for a new era of polar materials.

1 496 941 €

Start date: 2019-01-01, End date: 2023-12-31

"I propose a systematic study of the type of genetic variation enabling adaptation and factors that limit rates of adaptation in natural populations. New methods will be developed for analysing data from experimental evolution and population genomics. The methods will be applied to state of the art data from both fields. Adaptation is generated by natural selection sieving through heritable variation. Examples of adaptation are available from the fossil record and from extant populations. Genomic studies have supplied many instances of genomic regions exhibiting footprint of natural selection favouring new variants. Despite ample proof that adaptation happens, we know little about beneficial mutations– the raw stuff enabling adaptation. Is adaptation mediated by genetic variation pre-existing in the population, or by variation supplied de novo through mutations? We know even less about what factors limit rates of adaptation. Answers to these questions are crucial for Evolutionary Biology, but also for believable quantifications of the evolutionary potential of populations. Population genetic theory makes predictions and allows inference from the patterns of polymorphism within species and divergence between species. Yet models specifying the fitness effects of mutations are often missing. Fitness landscape models will be mobilized to fill this gap and develop methods for inferring the distribution of fitness effects and factors governing rates of adaptation. Insights into the processes underlying adaptation will thus be gained from experimental evolution and population genomics data. The applicability of insights gained from experimental evolution to comprehend adaptation in nature will be scrutinized. We will unite two very different approaches for studying adaptation. The project will boost our understanding of how selection shapes genomes and open the way for further quantitative tests of theories of adaptation."

1 159 857 €

Start date: 2013-04-01, End date: 2018-03-31

"The attine fungus-growing ants are prime models for understanding phenotypic adaptations in social evolution and symbiosis. The mutualism has many hallmarks of advanced cooperation in its mating system commitments and functional complementarity between multiple symbiont partners, but potential conflicts between sexes and castes over reproductive priorities, and between hosts and symbionts over symbiont mixing have also been documented. With collaborators at BGI-Shenzhen and the Smithsonian Institution my group has obtained six reference genomes representing all genus-level branches of the higher attine ants and a lower attine outgroup. With collaborators in Denmark and Australia we have pioneered proteomic approaches to understand the preservation of sperm viability in spite of sperm competition and the enzymatic decomposition of plant substrates that the ants use to make their fungus gardens grow. Here, I propose an integrated study focusing on four major areas of attine ant biology that are particularly inviting for in depth molecular approaches: 1. The protein-level networks that secure life-time (up to 20 years) sperm storage in specialized ant-queen organs and the genetic mechanisms that shape and adjust these “sexual symbiome” networks. 2. The ant-fungal symbiome, i.e. the dynamics of fungal enzyme production for plant substrate degradation and the redistribution of these enzymes in fungus gardens through fecal deposition after they are ingested but not digested by the ants. 3. The microbial symbiome of ant guts and other tissues with obligate bacterial mutualists, of which we have identified some and will characterize a wider collection across the different branches of the attine ant phylogeny. 4. The genome-wide frequency of genomic imprinting and the significance of these imprints for the expression of caste phenotypes and the regulation of potential reproductive conflicts."

2 290 102 €

Start date: 2013-05-01, End date: 2018-04-30

Background Genetic exchange across species boundaries is emerging as a much more common phenomenon than previously assumed. This introduces potentially adaptive genetic variation into recipient populations. Such interspecies admixture is believed to have played an important role in domestication events, particularly in members of the Bos genus, which uniquely harbours no fewer than five independently domesticated lineages. Understanding these independent, yet reticulated evolutionary events is of fundamental interest for managing the genetic resources of domestic and wild bovids. Objectives I propose to investigate the role of interspecies admixture in domestication through four linked topics. The first is to systematically map the interspecies admixture among seven Asian Bos species, and to determine whether introgressed elements have been beneficial to the recipient populations. The second is to identify genes that have been under strong selection in each independent domestication process. The third is to link adaptively introgressed genomic elements with phenotypic effects. The fourth will address the future of genetic resources in all Asian Bos. Methods The project will bring together a large set of complete genomes and use a combination of population genetic and comparative genomic methods. Phenotypic data and experiments will be performed to validate the phenotypic effects of key introgressed elements and genes under selection during the domestication process. Expected outcome and importance The project will improve our understanding of the evolutionary dynamics of genetic elements that cross the species barrier, in particular the interplay between admixture and the domestication process. It will also provide important insights into the domestication process itself. A joint understanding of these processes is crucial for assessing which types of foreign genetic elements that can be useful for genetic improvement of domestic species.

1 499 275 €

Start date: 2020-02-01, End date: 2025-01-31