ABSTRACT
A major prerequisite for molecular genetic research in filamentous fungi is the availability of a gene transfer system. This consists of two main components: a vector containing a selectable marker and a transformation procedure to introduce the corresponding vector into the fungus. There has been substantial progress in developing transformation techniques for filamentous fungi during the last 25 years. Besides the unicellular yeast Saccharomyces cerevisiae, the filamentous fungi N eurospora crassa and Aspergillus nidulans have been studied intensively. Several excellent reviews on transformation systems and genetic engineering of filamentous fungi have been published (Fincham, 1989; Goosen et al., 1991; Timberlake and Marshall, 1989; Turner, 1991; Van den Handel and Punt, 1991). The molecular genetic systems of the two model organisms of filamentous fungi (N. crassa and A. nidulans) served as the basis for developing suitable transformation systems for less investigated but economically and industrially important fungal species (Timberlake and Marshall, 1989).
