Synthetic pluripotent bacterial stem cells

A defining property of stem cells is their ability to differentiate via asymmetric cell division, in which a stem cell creates a differentiated daughter cell but retains its own phenotype. Here, we describe a synthetic genetic circuit for controlling asymmetrical cell division in Escherichia coli. Specifically, we engineered an inducible system that can bind and segregate plasmid DNA to a single position in the cell. Upon division, the co-localized plasmids are kept by one and only one of the daughter cells. The other daughter cell receives no plasmid DNA and is hence irreversibly differentiated from its sibling. In this way, we achieved asymmetric cell division though asymmetric plasmid partitioning. We also characterized an orthogonal inducible circuit that enables the simultaneous asymmetric partitioning of two plasmid species – resulting in pluripotent cells that have four distinct differentiated states. These results point the way towards engineering multicellular systems from prokaryotic hosts.

Cell polarity and microtubule organisation during mouse early embryogenesis

We have studied the distribution and the role of microtubules in the major developmental events occuring during early development of the mouse. These events are the setting up of asymmetries within blastomeres, the process of asymmetrical cell division and the changes in cellular organisation taking place during epithelial differentiation.