Objective Understanding the evolution of multicellularity and cellular differentiation/ complexity is one of the greatest challenges in biology. Of particular interest is to determine the evolutionary processes (selective causes) and mechanisms underlying the evolutionary transition from single cells to multicellular organisms.This project will use cyanobacteria as a model system to determine whether cellular differentiation is a cause or consequence of multicellularity. A novel theory will be tested, which predicts that the division of labour/ differentiation among cells drives the transition to a multicellular state. This will be contrasted with the classical view, where cellular specialization originates only at a much later state during the transition. The proposed project will adopt an interdisciplinary approach by combining experimental evolution (WP1) with phylogenomics (WP2). More specifically, populations of unicellular cyanobacteria will be subjected to long-term experimental evolution under two different regimes that favour either the specialization of cells into performing different physiologically incompatible processes, or the formation of non-differentiated aggregates (WP1). By linking the phenotype to the underlying genotype and to gene expression patterns, the critical steps for the transition to multicellularity will be established at the genome level. This evolutionary sequence will be directly compared to the one inferred from the cyanobacterial phylogeny (WP2). Here, whole genomes will be used to reconstruct the gain and loss events for the main ‘multicellular traits’, such as filament formation and cellular differentiation.The findings will not only provide insight into the key events during the transition to multicellularity but will also be the first study that directly relates a transition that was achieved under artificial conditions in the laboratory to one that actually happened more than 3 billion years ago in this phylum. Fields of science natural sciencesbiological sciencesbiological morphologycomparative morphologyhumanitieshistory and archaeologyhistorynatural sciencesbiological sciencesevolutionary biologymedical and health sciencesclinical medicineoncologynatural sciencesbiological sciencesgeneticsgenomes Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2014-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF) Call for proposal H2020-MSCA-IF-2014 See other projects for this call Funding Scheme MSCA-IF-EF-RI - RI – Reintegration panel Coordinator CHRISTIAN-ALBRECHTS-UNIVERSITAET ZU KIEL Net EU contribution € 171 460,80 Address OLSHAUSENSTRASSE 40 24118 Kiel Germany See on map Region Schleswig-Holstein Schleswig-Holstein Kiel, Kreisfreie Stadt Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 171 460,80