Genomics of Filamentous Fungi

Large-scale sequence analysis of fungal genomes has been focused on yeast for a long time. The publication of the complete genome of budding yeast (Saccharomyces cerevisiae) heralded the era of eukaryotic genome analysis (Goffeau et al., 1996). Six years later the complete analysis of the fission yeast (Schizosacchawmyces pombe) genome was presented (Wood et al., 2002). The genomes of these yeast proved similar in size and gene content: the S. cerevisiae genome codes for approximately 6,500 proteins in a total of 12.6 Mb, while the 13.8-Mb genome of S. pombe includes about 5,000 genes. These yeasts diverged 400 million years ago, making them as distant from each other as from ascomycetous filamentous fungi like Aspergillus nidulans and Neurospora crassa, and yet about 80% of their genes reveal significant sequence similarity. In fact, the gene complement of these organisms may represent the minimal set of genes needed by a free-living eukaryote (Wood et al., 2002). Genomic sequencing is now being extended to the pathogenic yeast, Candida albicans, a hemiascomycete which can grow in unicellular form as well as filamentous form, and Cryptococcus neoformans, a basidiomycete (Heitman et al., 1999).