An essential feature of life is the generation of phenotypic variation and transmission to subsequent generations. This raises questions about the continuity of experience and memory, both at the cellular level, but also for whole organisms.
Epigenetic stability and plasticity in stem cell biology and cell fate
Stem cells are essential components of multi-cellular organisms and pose fundamental questions in terms of identity. They encapsulate some level of identity: organism identity with the genomic material and tissue identity in the case of adult stem cells. This identity must be stably maintained but also remain plastic to allow differentiation into many different cell types. Epigenetics mecanisms are involved in many aspects of stem cell biology. Together, the labex teams will investigate the question of epigenetic stability in human embryonic stem cells and tumors: How it can influence their fundamental properties (pluripotency); How this instability is linked to environmental stimuli; What are the common pathways involved in both tumor cells and embryonic stem cells? Importantly, understanding these processes is a fundamental prerequisite to any therapeutical use of human embryonic stem cells.
New cellular identities during differentiation and signal pathways?
The distinct somatic cell types within an individual organism contain the same genetic material but harbor distinct cellular identities associated with their differentiated tissue and functions. The establishment of these phenotypes is determined by a complex interplay between genome, epigenome, signaling networks and environmental cues. The Who am I? teams have generated much experimental evidence concerning the differentiation of hepatic, intestinal, renal, muscular, neuronal, and reproductive tissues. Together, they will delve deeper into (i) exploring the functions of key transcription factors and signaling pathways active during development and tissue homeostasis, (ii) understanding how the genome encodes adaptative response to a given developmental context and how adult stem cells acquire and maintain their identity during development and in their adult niche.
The impact of epigenome transmission on social identities
Recent advances in biological and physical research raise challenging ethical questions that impact on social sciences and which must be confronted by collaborations between social scientists and the bio-medical community. The impact of environmental cues on cellular identities and plasticity raises fundamental questions about the inherent nature of identity and the mode of transmission through time. Such discoveries add to historical debates exploring ‘epigenesis’ and ‘preformationist’ views of identity and development. The Who am I? teams ambition to bridge the gap between the life and social sciences and, together, explore the mechanisms responsible for establishing and transmitting identities.