A Drosophila asthma model - what the fly tells us about inflammatory diseases of the lung.

Asthma and COPD are the most relevant inflammatory diseases of the airways. In western countries they show a steeply increasing prevalence, making them to a severe burden for health systems around the world. Although these diseases are typically complex ones, they have an important genetic component. Genome-wide association studies have provided us with a relatively small but comprehensive list of asthma susceptibility genes that will be extended and presumably completed in the near future. To identify the role of these genes in the physiology and pathophysiology of the lung, genetically tractable model organisms are indispensable and murine models were the only ones that have been extensively used. An urgent demand for complementary models is present that provide specific advantages lacking in murine models, especially regarding speed and flexibility. Among the model organisms available, only the fruit fly Drosophila melanogaster shares a comparable organ composition and at least a lung equivalent. It has to be acknowledged that the fruit fly Drosophila has almost completely been ignored as a model organism for lung diseases, simply because it is devoid of lungs. Nevertheless, its airway system shows striking similarities with the one of mammals regarding its physiology and reaction towards pathogens, which holds the potential to function as a versatile model in asthma-related diseases.