ABSTRACT
A. nidulans is one of the critical fungal systems in genetics and cell biology. It is important because it is closely related to a large number of other Aspergillus species of industrial and medical significance (e.g., Aspergillus niger, Aspergillus oryzae, Aspergillus flavus, and Aspergillus fumigatus) and serves as a model for understanding many biological questions. Unlike other asexual Aspergillus spp., A. nidulans has a well-characterized conventional genetic system. Its advantages include compact colonial morphology, uninucleate conidia, homothallism, meiotic genetics, haploid nature, and the ability to construct diploids and perform mitotic analysis. The relative ease of handling as a laboratory organism facilitates the investigation of physiology, genetics, and molecular biology of a lower, althoughmulticellular, eukaryote; thus, A. nidulans has become a useful tool for fundamental research. Numerous auxotrophs, mutants in different metabolic pathways, and developmental mutants were isolated. Since transformation procedures were established for A. nidulans in the early 1980s [1-3], molecular genetic manipulation and reverse genetics have become standard techniques, and today all modern tools to study the regulation of gene expression or developmental processes can be used in A. nidulans.
