Brigitte Galliot Group
Department of Genetics and Evolution - Faculty of Science, University of Geneva
Project at a glance
My laboratory is interested in the molecular and cellular basis of regeneration and the regulatory networks that control adult and de novo neurogenesis.
To investigate these questions we are using the Hydra model system. Hydra is a simple freshwater cnidarian polyp that catches its food, contracts upon touch and walks thanks to a rather sophisticated nervous system. Moreover Hydra can regenerate any body part after bisection.
Over the past 20 years gene cloning and genome sequencing highlighted the surprisingly high level of conservation of the signaling pathways from cnidarians to vertebrates. Hydra thus provides a simple but potent model system to investigate the core mechanisms driving regeneration in eumetazoans.
Our research focuses on the following questions:
- what mechanisms maintain a dynamic homeostasis in Hydra?
- what mechanisms support regeneration, including de novo neurogenesis?
- what is the function and regulation of stem cells in these contexts?
- which of these mechanisms have been conserved across evolution?
In the recent years, we have shown that cell death plays a key role in the initiation of head regeneration as dying cells deliver signals that promote the proliferation of their neighbors (Chera et al., Dev Cell 2009; Chera et al., Dev Growth Diff 2011).
Interestingly cell death is important to launch compensatory regeneration in several bilaterian species including Drosophila, Xenopus or mice and thus might represent an evolutionarily-conserved mechanism to trigger regeneration.
For reviews on our research, see Galliot et al., Sem Cell Dev Biol, 2006; Galliot et al., Dev Biol, 2009; Galliot and Ghila, Mol Reprod Dev 2010; Galliot and Chera, Trends Cell Biol 2010; Galliot et al., Europ J Neurosci 2011.