Ultrastructural Studies of the Spore Wall of Gigaspora albida (Glomales)

Mycologia ◽  
1993 ◽  
Vol 85 (6) ◽  
pp. 883 ◽  
Author(s):  
Leonor C. Maia ◽  
James W. Kimbrough ◽  
Gerald Benny

Mycologia ◽  
1993 ◽  
Vol 85 (6) ◽  
pp. 883-889 ◽  
Author(s):  
Leonor C. Maia ◽  
James W. Kimbrough ◽  
Gerald Benny


1977 ◽  
Vol 55 (19) ◽  
pp. 2544-2549 ◽  
Author(s):  
Ching-Yuan Hung

Ascospores of Pyronema domesticum contain three distinct spore wall layers. The liberation of ascospores presumably commences immediately after the three spore wall layers are formed. This is evidenced by the fact that vesiculation of the investing membrane was observed at the time when three wall layers could be distinguished. Vesiculation continues until the total disappearance of the perispore. Concurrently the epiplasm of the ascus degenerates and converts into a large vacuole within the ascus. Spores are violently ejected through the apical pore that is surrounded by a weakened apical ring. Presumably eight ascospores are discharged at the same time but do not adhere as a single unit. The operculum is generally not hinged to the main body of the ascus and an ascus without ascospores degenerates.



1996 ◽  
Vol 74 (10) ◽  
pp. 1651-1656 ◽  
Author(s):  
Li-Tzu Li ◽  
James W. Kimbrough

Galiella is one of the genera of the dark-colored apothecial Sarcosomataceae, tribe Galielleae, with cyanophilous spore markings. Ultrastructural studies show that spore wall development of Galiella rufa is similar to the subgenus Discina of Gyromitra in Helvellaceae and to the other Sarcosomataceae, especially Plectania nannfeldtii, which both have fine secondary wall spore ornaments. The multinucleate ascospores found in G. rufa may show relationship to the Morchellaceae and the Helvellaceae. Keywords: ascospore ontogeny, Galiella, Sarcosomataceae, ultrastructure.



1996 ◽  
Vol 74 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Li-Tzu Li ◽  
James W. Kimbrough

Some species of the genera Phillipsia and Wynnea have similar longitudinally ridged cyanophobic ascospore markings. Ultrastructural studies show that the cyanophobic spore markings are part of the primary wall. In contrast, the cyanophilous spore ornaments are formed by the secondary wall. The observation of spore wall development indicates that the sources of the spore wall components are the sporoplasm and the epiplasm. Based on the pinkish hymenial color of fresh young apothecia and the cyanophobic spore ridges found only in some members of the Sarcoscyphaceae, Wynnea belongs to the Sarcoscyphaceae. Keywords: Pezizales, Phillipsia, Sarcoscyphaceae, spore wall ontogeny, ultrastructure, Wynnea.



1976 ◽  
Vol 54 (8) ◽  
pp. 698-705 ◽  
Author(s):  
A. Beckett

Ascospore germination in Daldinia concentrica has been studied using light and electron microscope techniques. Preliminary observations indicated that lipid globules were utilized during early stages of germination. Apical wall vesicles were localized during germ tube initiation and were involved in the differentiation of a filamentous germ tube. Wall synthesis occurred during germination and resulted in a new wall layer, which was different in ultratexture to the spore wall and which formed the germ tube wall. Possible implications of the concept of spore wall and vegetative wall types during germination are discussed.



1968 ◽  
Vol 14 (10) ◽  
pp. 1149-1154 ◽  
Author(s):  
J. L. Laseter ◽  
W. M. Hess ◽  
J. D. Weete ◽  
D. L. Stocks ◽  
D. J. Weber

Electron microscopic investigations and chemical analyses were made on the spores of three species of Tilletia. Frozen-etched preparations examined in the electron microscope revealed that the spore walls of both T. foetida (smooth external surface) and T. caries (reticulate surface with some hair-like projections) contain two layers. The spore wall of T. controversa (complex reticulate surface with many hair-like projections) contains three layers. The outer layer in T. controversa has granular regions which form a reticulated pattern on the surface. The hydrocarbon content of the three Tilletia species was essentially the same. The compounds in benzene and the methanol (free fatty acids) fractions gave distinct gas chromatographic patterns for each of the three species. T. foetida was the highest in saturated fatty acids with T. controversa second followed by T. caries. The reverse situation existed with respect to the unsaturated fatty acids.



1989 ◽  
Vol 67 (9) ◽  
pp. 2576-2589 ◽  
Author(s):  
J. P. Latgé ◽  
D. F. Perry ◽  
M. C. Prévost ◽  
R. A. Samson

Wall development during primary spore formation, discharge, and germination of Entomophthorales is emphasized in ultrastructural studies of Conidiobolus, Entomophaga, Neozygites, and Erynia. In the fungi examined, spore and sporophore walls consist of a thick, electron-translucent inner layer and a thin, electron-dense outer layer. During spore formation, cytoplasm of the supporting sporophore cell migrates into the spore initial. As the former cell empties, a septum develops. Discharge is caused by inversion of the papillum, which lacks the electron-dense layer. Only in Erynia did the two spore wall layers separate upon impact. Intracytoplasmic organization of the primary spore is typical of the Zygomycotina; the morphology of organelles was characteristic of species, whereas nuclear ultrastructure was consistent within genera. Conidiobolus nuclei have a prominent nucleolus that lacks heterochromatin, in contrast with the other genera where large patches of heterochromatin were observed. Upon germination, no rupture of the spore outer layer was observed other than at points of germ tube emergence. The germ tube wall was continuous with the inner spore wall layer. The results are discussed in reference to Entomophthorales taxonomy and definition of the terms conidium and monosporous sporangiolum.



1994 ◽  
Vol 72 (10) ◽  
pp. 1550-1559 ◽  
Author(s):  
M. Yusoff ◽  
E. B. G. Jones ◽  
S. T. Moss

This paper reports results of ultrastructural studies of ascospores and their appendages in Ceriosporopsis caduca, Ceriosporopsis circumvestita, and Ceriosporopsis capillacea. Ceriosporopsis caduca and C. capillacea have polar appendages that arise as outgrowths of the spore wall. The exosporium, which initially extends over the polar appendages, later forms a collar at their base. In C. circumvestita, the sheath is mesosporial in origin and is chambered; an exosporium is absent, and there is no collar at the base of the appendage. Because of the difference in ascospore appendage structure, C. circumvestita is transferred to a new genus Lautisporopsis. The taxonomy of the remaining species of Ceriosporopsis is reviewed, and comparisons are made with Bovicornua intricata. Key words: Ascomycotina, marine fungi, taxonomy, ultrastructure, Lautisporopsis.



Microbiology ◽  
2000 ◽  
Vol 81 (2) ◽  
pp. 291-302 ◽  
Author(s):  
ANNE McVITTIE

Summary: Examination of thin sections of sporulating wild-type colonies revealed new structural details of the development of the sporulation-septum walls. Spores with very thick (about 75 nm) three-layered walls were seen in spore preparations. Of the sporulation defective (whi) mutants examined, whiDI6 was defective in spore-wall thickening while whiF99 was defective in rounding up and produced rod-shaped, thick-walled spores. A third mutant (whi-92) showed occasional abnormality in sporulation-septum spacing and produced immature as well as mature spores. One mutant (whi-53) produced only a few spores, all structurally normal. In two whiE mutants, structural abnormalities in spores were absent or rare.



1995 ◽  
Vol 73 (11) ◽  
pp. 1761-1767 ◽  
Author(s):  
Li-Tzu Li ◽  
James W. Kimbrough

Pseudoplectania and Plectania currently belong to the Sarcosomataceae, tribe Sarcosomateae, a group with members lacking cyanophilic spore markings (absorbing a blue stain). The two genera are morphologically similar in having blackish discoid-shaped apothecia but differ in having globose and ellipsoid spores, respectively. Ultrastructural studies show that ascospores of Pseudoplectania nigrella (Pers. ex Fr.) Fuckel lack a secondary wall layer. On the contrary, Plectania nannfeldtii Korf has secondary spore wall ornamentation that is cyanophilic under a light microscope. The data suggest retention of Pseudoplectania nigrella in the Sarcosomateae; however, the position of certain species of Plectania needs to be reevaluated. Key words: Pezizales, Plectania, Pseudoplectania, Sarcosomataceae, spore ontogeny, ultrastructure.



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