Filamentous fungal genomes range in size from two to five times that of yeast. Reflecting their increased genetic complexity, filamentous fungi contain more genes than do yeasts. By extending genomic sequence information from yeast to filamentous fungi and eventually to Basidiomycetes, the ability to understand and manipulate many aspects of growth, metabolism, and development will be at our fingertips. Filamentous fungi produce an extraordinary number of secondary metabolites, including known mycotoxins such as aflatoxin and commercially important antibiotics such as penicillin. Unlike yeast, most fungi form distinct asexual spores that constitute the chief means of dispersal of the organism, and therefore the chief means of infection for pathogens.
Filamentous fungi have substantially greater metabolic versatility than yeast.
They can grow at pH ranging from 2.5 to 11, at salt concentrations over 4 M, at temperatures from 5 C to 60 C, and on a staggering number of different and exotic carbon and nitrogen sources. Circadian rhythms occur in Neurospora and mammals but not in yeast, and Neurospora is one of the model organisms for the study of biological clocks. The Neurospora genome sequence would contribute to understanding of this complicated phenomenon, one of many we would like to address using a biocomplexity approach. A readily testable hypothesis considers the response to light as a possible adaptation to temperature changes . As a group, fungi are known for the exceptional ease with which they can be genetically and molecularly manipulated.