Challenges and Controversies in Choosing a Model Organism

Selection of an appropriate model organism is a vital step in good experimental design. A number of articles published in PLoS Pathogens over the past month have touched on this topic…

The malaria research community has, over recent years, been engaged in a debate on the use of animal models in the research of severe malaria. This most recently culminated in a meeting of minds in Hinxton in the UK where researchers working with experimental animal models and those working with humans infected with malaria discussed recent research controversies. One of the key take home points from this discussion, which is described in a recent PLoS Pathogens Opinion article, was the need for greater communication between the two research communities to ensure that research in animal models will be applicable to the human disease state.

While it is no easy task to establish a suitable model for any disease system, things become even more complex when investigating multiple infections in the same organism.  Co-infection of tuberculosis (TB) is the single greatest cause of AIDS-related deaths. With the recent development of HIV mouse models researchers now have greater options for the modeling of HIV/TB co-infection. Previously, due to HIV’s specificity for human cells, the only model organism was the related Simian Immunodeficiency Virus (SIV) in macaques. The availability of new animal models means that even more consideration is required to select the best model for your research question.  Pawlowski et al. discuss some of the uses and limitations of these new models in a review published this week in PLoS Pathogens, which focuses on the immunological and pathogenic mechanisms of the synergistic interaction between HIV and TB.

And lastly, Desalermos et al. have produced an introductory guide to selecting the best invertebrate model host for your research. It’s written in the context of fungal pathogenesis but addresses topics such as mutant-availability, temperature sensitivity and virulence that would be applicable to bacteriologists and virologists as well. The guide outlines the questions you should pose when selecting the model to best fit your experimental hypothesis, because, as the authors point out, “no single model host can answer all scientific questions”.