A key feature of living organisms is their capacity to change over time and to adapt to their environment. The identity of contemporary organisms or cells is therefore also the result of their evolutionary history. Who am I? partner teams will explore the patterns of evolutionary change that lead to the present-day species, especially human beings.
Evolution of genomes and cells
Animals are composed of myriads of specific cell types with defined morphological, molecular and functional properties. The labex teams will explore how cell identities are established, maintained and diversified during animal evolution. A "molecular fingerprint" approach will be followed, i.e. define cell identity in terms of gene regulatory networks (GRNs) active in a given cell type and/or involved in its formation. Comparisons of GRN between distantly-related animals will allow to study the evolution of cell identity and the GRN involved in its establishment at the organism scale.
Evolution of genomes, organs and organisms
The diversity of forms of living organisms is an essential part of biological identity but the bases for evolutionary transitions in shape are still to be precisely decribed. Despite extensive variabilities, animal anatomies have retained some remarkably conserved structures and developmental processes, such as metameric segmentation, gastrulation or neural tube formation. The Who am I? labex teams will (i) explore the genetic control of morphogenesis by searching for genes responsible for morphological differences between closely-related species (ii) try to understand how physical properties of cells/tissues (e.g. visco-elasticity of tissues) and of the morphogenetic processes (e.g. symmetry breaking events or physical bifurcations) affect forms and lead to transition between forms during the course of evolution.
Evolution of genomes and populations of organisms
In order to gain insights into the link between genomic variability and microevolutionary changes, the Who am I? teams will study genomic variability at the individual and population level in humans and domestic cattle during short evolutionary periods with intense evolutionary changes. The links between genome variability and selective pressures will be analyzed with emphasis on the regulatory changes thanks to the integration of genetic variability and functional epigenomic data. Population comparison will help to understand to which extent genetic load is variable among populations and if it depends on the environment or the reproductive system.