Research topics involving Dictyostelium discoideum:

  • Small molecule signalling
  • Symbiotic associations with bacteria
  • Iron acquisition
  • Interactions with the pathogen Pseudomonas aeruginosa
  • Interactions with its predator Dictyostelium caveatum

The social amoeba Dictyostelium discoideum represents one of the earliest branches of the common ancestor of all eukaryotes thus rendering it an ideal model organism in studying general eukaryotic cellular mechanisms. Differentiation and multicellularity in this protist, however, have evolved in a setting where D. discoideum is surrounded both by mutualistic and pathogenic bacteria. Only in consideration of this ecological context, can a deep understanding of the fundamental molecular communication and signalling processes be gained. For communication purposes bacteria and the eukaryotic amoeba have evolved mechanisms to produce signals, as well as cognate sensors. While current research has revealed key aspects of intra-species communication (e.g. quorum sensing in bacteria or the differentiation-inducing small molecules in D. discoideum), very little is known about inter-species communication between bacteria and eukaryotes. Coevolution of different species typically results in the fact that interplayers adopt components of each other’s language. The common language that is of interest to us consists of secreted small molecules. Isolating these compounds, elucidating their structure and determining their function in symbiotic associations will be our main focus.

The main advantages of studying the D. discoideum-bacteria association lie in the inherent simplicity of the system. Importantly, a single bacterial strain can be analysed with a single eukaryotic host clone. ‘Many-body’ effects arising from complex interactions between a multitude of different bacterial strains and a mammalian host can be reduced in our minimalistic model. In addition, understanding how small molecules selectively interfere with the early eukaryote’s differentiation and association machinery will provide us with insight for modulating mammalian cellular mechanisms. Ideally, these findings will allow us to identify basic communication modes between bacteria and their host and thus guide us towards crucial questions that can be asked in complex mammal-bacterial interactions.

For more information please visit our webpage: www.stallforth-lab.de