We are interested in understanding the evolution of stem cell gene regulatory networks. To address this fundamental question of animal evolution, we use sponges as a model system. Sponges are one of the most basally branching animal phyla, and therefore particularly suited to reconstruct ancestral stem cell regulatory mechanisms. Our work capitalizes on the establishment of a novel sponge regeneration system, which allows us to interrogate stem cell differentiation processes. We are implementing a number of single-cell transcriptomic and genomic techniques, as well as advanced computational methods, to infer gene regulatory interactions that control stem cell differentiation.

An estimated 600 million years ago, the first multicellular animal, with the ability to generate distinct cell types through the process of stem cell differentiation, evolved from a unicellular ancestor. Despite its profound importance, we still know very little about this evolutionary event. Our work on sponge stem cells, together with our collaboration with groups working on unicellular organisms, promises to elucidate key gene regulatory changes that took place during the evolution of multicellularity. In addition, the very simple body plan of sponges makes them instrumental to elucidate fundamental principles of stem cell biology and regeneration.