Genetic transformation in Aspergilli: tools of the trade

DNA-mediated transformation is a powerful tool that allows the introduction of specific genetic changes in an organism. Transformation of Aspergilli, acclaimed for their wide use in the industry, has been possible for about two decades now. Several basic and applied problems related to fungal biology have been addressed using this technique. Nonetheless, new markers and strategies for transformation are still being developed for these filamentous fungi. Different methods and markers that are currently available for the transformation of Aspergilli are summarized here. The review also brings out the importance of these transformation systems in analyzing fungal gene function. Aspects of Aspergillus niger transformation are selectively emphasized.