Fimbriae of coprinus cinereus, schizophyllum commune and ustilago violacea = structural aspects and a role in conjugation
Year: 1990
Type: dissertation
Abstract: Surface fibrils (fimbriae) have been observed on fungi from every major \ngroup. Fimbriae are thought to be involved in the following cell to cell \ninteractions: conjugation, flocculation and adhesion. Several higher fungi \nexibit two other types of interactions: hyphal fusion (anastomosis) and \nclamp connection formation. As a prelude to examining the role of \nfimbriae in these processes, the fimbriae of two fungi that undergo these \nfusion events were examined. \nElectron microscopy studies revealed that Coprinus cinereus and \nSchizophyllum commune are fimbriated. C. cinereus fimbriae were 5 nm \nin diameter and 0.5 to 20 11m in length. Fimbriae of C. cinereus oidia were \nmore numerous and longer than those of the hyphal stage. S. commune \nfimbriae were also 5 nm in diameter, but were only 0.5 to 2 11m in length. \nThere was an unequal distribution of fimbriae on the hyphal surfaces of S. \ncommune . Fimbriae were sparsely distributed over the entire hyphal \nsurface, with higher densities of fibrils present on the side growths of the \nhyphae found in the older sections of the mycelium. \nAntiserum raised against Ustilago violacea fimbrial protein (AU) crossreacted \nstrongly with 37 and 39 kd C. cinereus mycelial proteins. In \ncontrast, AU bound very weakly to 89 and 92 kd S. commune mycelial \nproteins. Since AU cross-reacted poorly with S. commune fimbrial \nproteins, it was impossible to further characterize the fimbriae of this \nspecIes. The 37 and 39 kd C. cinereus proteins, were isolated by \nelectroelution and were shown to be able to form fibrils the same diameter \nas oidial fimbriae. The 37 kd protein was shown to be composed of several \nproteins with isoelectric points ranging from pH 6.1 to 7.63. Furthermore, \nthe 37 kd protein was found to be multimeric, while the 39 kd protein was \nnot. These results strongly suggested that the 37 kd protein is the \nstructural fimbrial protein of C. cine reus . \nFinally, a series of experiments were designed to determine whether \nfimbriae are required for conjugation in U. violacea Conjugation was \ninhibited significantly with AU, but not with pre-immune serum or AU \npreincubated with purified fimbrial protein. Thus, it was concluded that \nfimbriae play a central role in mating in this organism.
Author: Robert P. Boulianne
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1551330471