Biomaterial Database

A freeze-fracture study of hormone-induced branching in the fungus Achlya. 1979

J T Mullins

The induction of the male sexual organ primordia (antheridial hyphae) by the steriod hormone antheridiol in the water mold Achlya ambisexualis Raper requires the production and secretion of the enzyme cellulase. It is postulated that a localized secretion of cellulase produces a limited area of wall hydrolysis that is blown out into a lateral bleb by turgor pressure. Freeze-etch preparations show membrane profiles similar to those seen in other systems where exocytosis is occurring. Such a mechanism would provide the required localized secretion of cellulase. Water stress, imposed by polyethylene glycol, prevents the formation of antheridial hyphae, the secretion of cellulase and the expected membrane profiles. After a period of recovery from water stress antheridial hyphae are formed, cellulase secretion occurs and the expected membrane profiles are restored.

UI	MeSH Term	Description	Entries
D010840	Phytosterols	A class of organic compounds known as sterols or STEROIDS derived from plants.	Plant Sterols,Phytosteroid,Phytosteroids,Phytosterol,Plant Steroid,Plant Steroids,Plant Sterol,Steroid, Plant,Steroids, Plant,Sterol, Plant,Sterols, Plant
D011092	Polyethylene Glycols	Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.	Macrogols,Polyoxyethylenes,Carbowax,Macrogol,Polyethylene Glycol,Polyethylene Oxide,Polyethyleneoxide,Polyglycol,Glycol, Polyethylene,Glycols, Polyethylene,Oxide, Polyethylene,Oxides, Polyethylene,Polyethylene Oxides,Polyethyleneoxides,Polyglycols,Polyoxyethylene
D002480	Cellulase	An endocellulase with specificity for the hydrolysis of 1,4-beta-glucosidic linkages in CELLULOSE, lichenin, and cereal beta-glucans.	Endo-1,4-beta-Glucanase,Cellulysin,Endoglucanase,Endoglucanase A,Endoglucanase C,Endoglucanase E,Endoglucanase IV,Endoglucanase Y,beta-1,4-Glucan-4-Glucanohydrolase,Endo 1,4 beta Glucanase,beta 1,4 Glucan 4 Glucanohydrolase
D005089	Exocytosis	Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
D005613	Freeze Etching	A replica technique in which cells are frozen to a very low temperature and cracked with a knife blade to expose the interior surfaces of the cells or cell membranes. The cracked cell surfaces are then freeze-dried to expose their constituents. The surfaces are now ready for shadowing to be viewed using an electron microscope. This method differs from freeze-fracturing in that no cryoprotectant is used and, thus, allows for the sublimation of water during the freeze-drying process to etch the surfaces.	Etching, Freeze
D005658	Fungi	A kingdom of eukaryotic, heterotrophic organisms that live parasitically as saprobes, including MUSHROOMS; YEASTS; smuts, molds, etc. They reproduce either sexually or asexually, and have life cycles that range from simple to complex. Filamentous fungi, commonly known as molds, refer to those that grow as multicellular colonies.	Fungi, Filamentous,Molds,Filamentous Fungi,Filamentous Fungus,Fungus,Fungus, Filamentous,Mold