Organelles of Filamentous Fungi

Abstract

Filamentous fungi are typical eukaryotes in many respects and contain a wide range of membrane-bounded subcellular compartments which are the sites of specialised functions. These are organelles as defined by the possession of a bounding membrane. Filamentous fungi contain all the major organelles with the key exception of the chloroplast, which is absent from all of these non-photosynthetic organisms. In addition, the occurrence of a structurally identifiable Golgi apparatus, with the classic dictyosome organization of stacked disc-shaped cisternae, is rare among filamentous fungi. It is common only in the Mastigomycotina, most notably in the class Oomycetes (CR9 et al., 1974), a group which shows many affinities with algae and may only be tenuously related to most filamentous fungi (CR7, 1987; CR20, 1987a, CR20, 1987b). A comparison of the genomic sequences coding for small-subunit ribosomal RNA has indicated that Oomycetes, represented by Achlya bisexualis, are very closely related to the chrysophytes (golden-brown algae) and show far less similarity to green algae or to ascomycete fungi (CR41 et al., 1987).