Objectif The evolution of multicellularity allowed specialization of cells into functions that support rather than cause propagation. While yielding immense gain of function, the organisation of these somatic cells into tissues and organs required novel cell-cell signalling systems. We seek to identify the genetic changes that caused transitions to multicellularity and enabled cell specialization. We use genetically tractable Dictyostelia with multicellular structures that contain from 1 to 5 cell-types to address these fundamental questions. Dictyostelia evolved from unicellular Amoebozoa and are subdivided into 4 major groups, with most novel cell-types appearing in group 4. We found that gene expression patterns changed most frequently at the transition between groups 3 and 4, and that across groups ~10% of genes were alternatively spliced in the 5’UTR, indicative of promoter elaboration. Among known genes essential for multicellular development, those involved in intracellular signal processing were mostly conserved between Dictyostelia and unicellular Amoebozoa, while those encoding exposed and secreted proteins (ESPs) were unique to Dictyostelia or groups within Dictyostelia. Starting from a hypothesis that diversification of ESPs and gene regulatory mechanisms are major drivers of multicellular evolution, we will place unicellular relatives of Dictyostelia under selection to induce multicellularity, establish which genes are most changed in evolved populations and whether this involves ESP families that are also most changed in Dictyostelia. We will overexpress altered genes in unicellular forms to assess whether this induces multicellularity. We will retrace evolution of cell specialization by lineage analysis and phenotyping and seek correlations between cell-type innovation and alternative splice events and with emergence of novel signalling genes. Causality will be assessed by replacement of genes or promoters with ancestral forms in evolved species and vice versa Champ scientifique natural sciencesbiological sciencescell biologynatural sciencesbiological sciencesgeneticsmutationnatural sciencesbiological sciencesgeneticsRNAnatural sciencesbiological sciencesgeneticsgenomesnatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes Mots‑clés Evolution of multicellularity evolution of development Dictyostelium social amoeba evolution of sociality Programme(s) H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC) Main Programme Thème(s) ERC-2016-ADG - ERC Advanced Grant Appel à propositions ERC-2016-ADG Voir d’autres projets de cet appel Régime de financement ERC-ADG - Advanced Grant Institution d’accueil UNIVERSITY OF DUNDEE Contribution nette de l'UE € 2 128 602,00 Adresse Nethergate DD1 4HN Dundee Royaume-Uni Voir sur la carte Région Scotland Eastern Scotland Angus and Dundee City Type d’activité Higher or Secondary Education Establishments Liens Contacter l’organisation Opens in new window Site web Opens in new window Participation aux programmes de R&I de l'UE Opens in new window Réseau de collaboration HORIZON Opens in new window Coût total € 2 128 602,00 Bénéficiaires (1) Trier par ordre alphabétique Trier par contribution nette de l'UE Tout développer Tout réduire UNIVERSITY OF DUNDEE Royaume-Uni Contribution nette de l'UE € 2 128 602,00 Adresse Nethergate DD1 4HN Dundee Voir sur la carte Région Scotland Eastern Scotland Angus and Dundee City Type d’activité Higher or Secondary Education Establishments Liens Contacter l’organisation Opens in new window Site web Opens in new window Participation aux programmes de R&I de l'UE Opens in new window Réseau de collaboration HORIZON Opens in new window Coût total € 2 128 602,00
