Independent research on DNA repair in mammalian cells and on photomorphogenesis in plants led to the discovery of common factors, the DNA Damage Binding complex, which is likely to act in a similar way in these two different processes by modulating access to chromatin-packed DNA. The DDB complex is not an integral component of the nucleotide excision repair (NER) machinery but becomes tightly bound to chromatin upon UV irradiation and associates with chromatin remodelling and ubiquitination activities. Thus, it could rather participate in early steps, helping the DNA repair machinery to access the DNA lesions. Considering its binding to nonacetylated histone H2B tails, a similar biochemical function of the plant DDB1/DET1 complex has been proposed by the host group, in order to regulate transcription of light-responsive genes at a global level during photomorphogenesis. We propose to purify the Arabidopsis DDB1/DET1 complex and to characterize its role in chromatin remodelling at loci of UV-damaged DNA and developmental genes in the broad context of plant photomorphogenesis. The complex will be immobilized on sepharose and binding assays will be performed with mononucleosomes purifed from dark/light-grown and UV-irradiated A. thaliana seedlings. Its function will also be assessed using a recently established plant in vitro DNA repair system, and its genomic targets will be investigated by chromatin immunoprecipitation. This project contributes to the current strong interest of plant scientists in studying epigenetic control of gene expression, and would allow me to investigate, on a longer term, a challenging and fascinating new field of gene regulatory mechanisms.

Terminal differentiation of cells is characterized by the acquisition of the specialized phenotype coincidental with cell cycle arrest. The aim of this proposal is the delineation of protein-protein interactions that distinguish processes of terminal differentiation, cell cycle arrest and tumorigenesis. To achieve this goal I will combine mouse genetic approach with Tandem Affinity Purification (TAP) technology to identify protein complexes formed in vivo by the basic region-leucine zipper protein C/EBPa essential for differentiation of various tissue types. Using knockin mice expressing C/EBPa-TAP fusion protein or its functional mutants I will analyze their proteomes in vivo to get a mechanistic insight into the role of transcription factors in complex biological processes such as differentiation and growth arrest in multiple tissue types. I will also address the function of novel interactors by mouse genetic approach. I received an extensive experience in protein functional analysis in vitro and in cellular systems the mouse model-based project will allow me to address biological questions at the organism level. I will obtain indispensable knowledge of mouse genetics and biology, learn to generate and analyze multiple mouse strains, while continuing my strong interest in the mechanisms of transcriptional control of normal and aberrant developmental processes.

Cell lineage specific transcriptional programmes are set early in development and maintained, via epigenetic mechanisms, throughout the lifetime of an organism. The failure of maintaining &#8216 cell memory&#8217 may result in cell identity deviance, deregulation of cell proliferation, altered developmental programmes and cancer. Modulation of chromatin structure appears to be a key pathway controlling transcription memory. The balanced action of chromatin regulators of the PcG and trxG groups controls the expression of homeotic as well as of most developmentally regulated genes. There is an increasing evidence that PcG/trxG genes might be involved in control of cell proliferation and cell cycle progression, including stem cell renewal and tumor progression. By combining molecular (chromatin immunoprecipitation, RNAi/ribozymes) and cytological (BrdU-incorporation, histone modifications immunodetection) approaches, the aim of this project is to get more insight into the role of PcG/trxG proteins in cell totipotency and epigenetic levels of genome reprogramming. The proposed research would significantly broaden my experimental skills, and challenge entirely new aspects of genome function, namely how epigenome reprogramming may influence cell identity definition and redefinition.

During my PhD study, I dealt with neurological questions related to promotion of recovery from spinal cord injury (SCI) and to the mechanisms involved in CNS degeneration. Throughout this period I was overwhelmed by the capability of controlled cell-mediated immunity to determine the outcome of CNS injury. I have witnessed significant differences in functional recovery, which correlated with the timing, dosage and antigenic specificity of immune cells homing to the lesion site. Uncontrolled hyperinflammation led to exacerbation of the damaged while a benign, well-regulated response significantly improved recovery from SCI. Since CNS inflammation is generally considered harmful, the current treatment for SCI includes a high dose of immunosuppressive steroids. However, my view is that controlled-inflammation may be developed as a therapeutic strategy of harnessing the body's own healing process for the treatment of degenerative pathologies. Therefore, in my postdoctoral study I would like to lay aside neurobiology and learn more about immune regulation, applying both animal 'in vivo' models and the human 'in vitro' system. Control over the induction of tolerance and immunity, will allow treatment of autoimmune diseases without complete immunosuppression, and "safe" activation of specific immune responses towards toxic self-compounds and malignant cells, in accordance with particular tissue requirements .It is a new discipline and I will have to acquire numerous new techniques, but I believe that the combination of my current knowledge with the expertise I will obtain, will enable me to develop into a skilled researcher in the field of neuroimmunology.

Ascidians are invertebrates with a basic chordate body plan. The extent to which the ascidian larval central nervous system (CNS) diverged from the complex vertebrate CNS provides information about key innovations during chordate CNS evolution. Gene expression patterns of members of the Hedgehog (Hh) signaling pathway in ascidians suggest conservation of signaling pathways involved in chordate CNS development. The application of technologies now available in ascidian research permits functional studies and the characterization of regulatory networks underlying formation of the CNS. Here we would like to focus on Shaggy/GSK3ß, which acts at the interface of the Hh and wingless/Wnt signaling pathway in both Drosophila and vertebrates. Analysis of Shaggy/GSK3ß function in the ascidian Ciona intestinalis will provide insight in the evolution of signaling pathways important for CNS development. Research on these signaling pathways in ascidians also offers a significant advantage over mouse research transgenic animals can be produced much faster, and the genome of ascidians is far less complex. In addition, the host laboratory is the only institute in Europe that performs genetic screens with ascidians. This presents the unique opportunity to screen for ascidian mutant phenotypes on a single cell level, which is just not possible in any vertebrate system. The host laboratory also has a long-standing interest in ascidian research and will provide an excellent environment to study ascidian biology. In combination with the research opportunities and recent advances in this field, this fellowship creates the possibility to become an independent researcher in a new promising field.