ISSN:
1615-6102
Keywords:
Apical growth
;
Brefeldin A
;
Immunocytochemistry
;
Fungus
;
Golgi body
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Candida albicans, a dimorphic yeast, has the abililty to switch its growth form between budding growth and hyphal growth. Since fungal growth involves secretory processes, spatial control of secretion should play a crucial role in such a morphogenetic transition. Brefeldin A (BFA), an inhibitor of the membrane trafficking system of eukaryotes, increases the occurrence of Golgi-like cisternae in the yeast. In the present study, BFA was used to obtain further insights into the spatial organization of secretory processes in hyphal growth ofC. albicans. BFA completely inhibited the formation and growth of germ tubes at a concentration of 35 μM or higher. Electron microscopy of BFA-untreated germinated cells revealed many vesicles in the apical region and Golgi-like cisternae in the cytoplasm. In cells treated with 35 μM BFA, the vesicles disappeared from the apical region, and, instead, stacked membrane cisternae and membrane-enclosed spherical dense bodies accumulated in the subapical region. These accumulated structures were positive for both polysaccharide staining and immunocytochemical staining with antibodies raised against cell surface antigens ofC. albicans, as were Golgi cisternae in BFA-untreated cells. In cells treated with a higher concentration of BFA (140 μM), the structures that appeared in cells treated with 35 μM BFA were no longer observed and the endoplasmic reticulum was extended and positive for polysaccharide staining. These results suggested that BFA affects different steps of membrane trafficking in a concentration-dependent manner. The accumulated structures induced by 35 μM BFA seemed to be the altered forms of Golgi cisternae. Their accumulation in the subapical region of the germ tube might indicate that the step(s) in membrane trafficking that are associated with the Golgi pathway are vectorially organized in hyphal growth ofC. albicans.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01279883
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