Christiaen Group
We use genome engineering, quantitative imaging, single cell genomics and computational biology to study gene regulation, fate decisions and cellular behaviors during development of marine embryos, and the cellular and molecular bases of adaptation to environmental conditions in the ocean.
Main content
During animal development, tissues and organs assume shapes and positions that are largely determined by the species-specific genetic blueprint. These macroscopic events are powered by a variety of cells that divide, change shape and move in response to cell-cell communications and lineage-specific genetic programs. Our overarching goal is to reach a system’s level understanding of how tissue-specific regulatory programs and cell-cell communications coordinate the fate choices and cellular behaviors that underlie animal development, regeneration and evolution.
In marine invertebrate embryos, fundamental cellular and molecular processes are directly exposed to environmental conditions in the ocean. Working from the ocean to the lab and back, we seek to uncover the cellular and molecular basis of adaptation to environmental conditions.
For many years, we have been focusing on cardiopharyngeal lineages, which produce both cardiomyocytes of the second heart field and head muscles from Mesp1+ anterior mesoderm progenitors. The cardiopharyngeal paradigm casts new light on certain congenital diseases characterized by the co-occurence of cardiac and craniofacial defects, which illustrates the biomedical relevance of our work on the regulation of cardiopharyngeal multipotency and early heart vs. pharyngeal muscle fate choices.
Circumventing the complexity of vertebrates, we use embryos and larvae of the tunicate Ciona to study cardiopharyngeal development with high spatial and temporal resolution. In ascidians like Ciona, every invariant division and migratory events are mapped onto a stereotyped and evolutionarily conserved developmental sequence. Leveraging the simplicity of the Ciona embryo and our a cutting edge experimental toolkit, we pursue a system’s level understanding of lineage-specific gene regulation, fate decisions and cellular behaviors during development.
We are expanding the scope of our research towards (1) the evolution of cardiopharyngeal development through comparative studies in tunicates and vertebrates, including mammalian stem cell models; (2) the regenerative potential of cardiopharyngeal structures in tunicates and their relationships with other endomesodermal systems, in post-embryonic stages; and (3) environmentally-relevant problems in developmental systems biology, especially the molecular and cellular basis of thermal adaptation across latitudes along the European coastline.
