Dictyostelium as a model for human disease.

Does it make sense to use a simple organism to study human disease? I am sure that all those scientists using non-mammalian models in biomedical research have faced this question many times, perhaps informally in front of the family and friends or in more critical situations under the scrutiny of grant agencies or evaluation committees. There are obvious arguments supported by the history of science telling us the usefulness of learning from simple models and how this has become essential to understand certain pathologies. In addition to the well-known conservation of genes and molecular pathways among distant species there are practical reasons, such as their simplicity and tractability compared with the complexity and the experimental inaccessibility of the human body. An added value from the studies of simple models is that, not infrequently, they open radically new perspectives in the study of a given pathology. This is often the result of applying unbiased genetic analysis and the opportunity in a model organism to address the function of a given gene in the organism as a whole. As a consequence, this research might not be translated immediately to human disease but serve as a ground for more applied approaches. As Louis Pasteur stated “There does not exist a category of science to which one can give the name applied science. There are sciences and the applications of science, bound together as the fruit of the tree which bears it”. This series of reviews exemplifies beautifully howthe social amoeba Dictyostelium fulfills all the requirements for a useful experimental model in understanding the basic principles of human disease.