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1.
Bareetseng AS Kock JL Pohl CH Pretorius EE Strauss CJ Botes PJ Van Wyk PW Nigam S 《Systematic and applied microbiology》2006,29(6):446-449
The distribution of 3-hydroxy oxylipins in Saturnispora saitoi was mapped using immunofluorescence microscopy. Fluorescence was observed on aggregating ascospores, indicating the presence of 3-hydroxy oxylipins on the surface or between ascospores. The oxylipin was identified as 3-hydroxy 9:1 using gas chromatography mass spectrometry. Furthermore, ultrastructural studies using scanning and transmission electron microscopy on ascospores revealed a clear equatorial ledge surrounding oval-shaped ascospores. 相似文献
2.
Smith DP Kock JL Motaung MI van Wyk PW Venter P Coetzee DJ Nigam S 《Antonie van Leeuwenhoek》2000,77(4):389-392
Upon cultivation of the yeast Dipodascopsis tothii in its sexual stage, small ascospores are released individually from the ascus tip, which then assemble in sheathed cluster balls. In contrast to Dipodascopsis uninucleata, this yeast produced smooth bean shaped ascospores with sheath-like appendages that assemble in a disordered sheathed ball of ascospores outside the ascus. Strikingly, upon release, the ascus tip contained 3-hydroxy oxylipins, while the released ascospore clusters contained little or no 3-hydroxy oxylipins as indicated by immunofluorescence microscopy. In D. uninucleata, these oxylipins are concentrated on the spore surface and interspore matrix, but not on the ascus tip. 相似文献
3.
Bareetseng AS Kock JL Pohl CH Pretorius EE Strauss CJ Botes PJ van Wyk PW Nigam S 《Antonie van Leeuwenhoek》2004,86(4):363-368
3-Hydroxy oxylipins were uncovered on ascospores of Eremothecium sinecaudum using immunofluorescence microscopy. This was confirmed by gas chromatography mass spectrometry. These oxylipins were observed only on ascospore parts characterised by nano-scale surface ornamentations simulating a corkscrew as demonstrated by scanning electron microscopy. Conventional ascospore staining further confirms its hydrophobic nature. Using confocal laser scanning microscopy we found that the corkscrew part with spiky tip of needle-shaped ascospores may play a role in rupturing the ascus in order to affect its release. Through oxylipin inhibition studies we hypothesise a possible role for 3-hydroxy oxylipins in facilitating the rupturing process. 相似文献
4.
Leeuw NJ Swart CW Ncango DM Pohl CH Sebolai OM Strauss CJ Botes PJ van Wyk PW Nigam S Kock JL 《Antonie van Leeuwenhoek》2007,91(4):393-405
Interesting distribution patterns of acetylsalicylic acid (ASA, aspirin) sensitive 3-hydroxy (OH) oxylipins were previously
reported in some representatives of the yeast genus Eremothecium—an important group of plant pathogens. Using immunofluorescence microscopy and 3-OH oxylipin specific antibodies in this
study, we were able to map the presence of these compounds also in other Eremothecium species. In Eremothecium cymbalariae, these oxylipins were found to cover mostly the spiky tips of narrowly triangular ascospores while in Eremothecium gossypii, oxylipins covered the whole spindle-shaped ascospore with terminal appendages. The presence of these oxylipins was confirmed
by chemical analysis. When ASA, a 3-OH oxylipin inhibitor, was added to these yeasts in increasing concentrations, the sexual
stage was found to be the most sensitive. Our results suggest that 3-OH oxylipins, produced by mitochondria through incomplete
β-oxidation, are associated with the development of the sexual stages in both yeasts. Strikingly, preliminary studies on yeast
growth suggest that yeasts, characterized by mainly an aerobic respiration rather than a fermentative pathway, are more sensitive
to ASA than yeasts characterized by both pathways. These data further support the role of mitochondria in sexual as well as
asexual reproduction of yeasts and its role to serve as a target for ASA antifungal action. 相似文献
5.
Smith DP Kock JL van Wyk PW Pohl CH van Heerden E Botes PJ Nigam S 《Antonie van Leeuwenhoek》2003,83(4):317-325
Immunofluorescence microscopy was used to assess members of the yeast genus Dipodascus for the presence of 3-hydroxy oxylipins. Fluorescence was associated with the aggregating ascospores in all species tested,
thus suggesting the association of 3-hydroxy oxylipins with these cells, especially the surrounding slime sheaths. An ultrastructural
study of the ascospores revealed sheaths with indentations, probably caused by the close packing of the ascospores to form
clusters. In addition, an increase in the neutral and glycolipid fractions as well as a decrease in the phospholipid fraction
during ascosporogenesis in D. ambrosiae was found.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
Ncango DM Pohl CH Sebolai OM Botes PJ Strauss CJ Joseph M Van Wyk PW Nigam S Kock JL 《Canadian journal of microbiology》2006,52(11):1046-1050
We previously implicated 3-hydroxy oxylipins and ascospore structure in ascospore release from enclosed asci. Using confocal laser scanning microscopy on cells stained with fluorescein-coupled, 3-hydroxy oxylipin-specific antibodies, we found that oxylipins are specifically associated with ascospores and not the vegetative cells or ascus wall of Ascoidea corymbosa. Using gas chromatography--mass spectrometry the oxylipin 3-hydroxy 17:0 could be identified. Here, we visualize for the first time the forced release of oxylipin-coated, hat-shaped ascospores from terminally torn asci, probably through turgor pressure. We suggest that oxylipin-coated, razor-sharp, hat-shaped ascospore brims may play a role in rupturing the ascus to affect release. 相似文献
7.
The ultrastructure ofCucullosporella mangrovei ascospores is described. Mature ascospores possess two wall layers, an outer electron-dense episporium and an innermost tripartite
mesosporium. Episporial elaborations form electrondense spore wall ornamentations from which extend fibrils that may constitute
a highly hydrated exosporium which was not visualised at either the scanning electron microscope or light microscope level.
Ascospores possess a hamate appendage at each pole which unfolds in seawater to form a long thread. Ultrastructurally the
polar appendage comprises folded fibro-granular electron-dense material and fine fibrils. The fibrils form a matrix around
and within the fibro-granular appendage and around the entire unreleased ascospore. These fibrils have not been observed associated
with the ascospore appendages in other species of the Halosphaeriales and are a discrete and new appendage component. The
fibro-granular appendage and fibrils are bounded by the outer delimiting membrane which is absent around released ascospores.
The nature of the spore appendage is compared with that of other marine and freshwater ascomycetes and the taxonomic assignment
of the species is discussed. 相似文献
8.
Lasiobolidium gracile isolated from a soil sample collected from California, USA is described as a new species. This species is characterized by
yellowish brown to reddish brown, nonostiolate ascomata with numerous, long straight appendages and a translucent peridium,
subglobose to broadly clavate asci, hyaline to pale yellowish brown, ellipsoidal ascospores. It differs from the other species
ofLasiobolidium in the straight and narrow appendages and the large ascospores. A key is presented separating the seven known species. 相似文献
9.
In the ceramiacean red alga Antithamnion nipponicum Yamada et Inagaki, the structure of the spermatial covering and appendages was examined using confocal laser scanning microscopy, scanning and transmission electron microscopy. The liberated spermatium was subspherical, ca 4.5 μm in size with a colorless covering 2.7–3.0‐μm thick. Two flexible, ribbon‐like appendages arose from the periphery of the spermatial covering. The appendages averaged 80 μm in length and were 0.5–0.6 μm width in most parts. Each appendage consisted of a number of thin longitudinal fibrils. Concanavalin A conjugated with fluorescein isothiocyanate, colloidal gold orferritin, bound specifically with the inner layer of spermatial covering and spermatial appendages. When the liberated spermatia were incubated with mature female gametophytes, the spermatial appendages entangled around the tricho‐gyne. 相似文献
10.
Sebolai OM Kock JL Pohl CH Botes PJ Strauss CJ Van Wyk PW Nigam S 《Canadian journal of microbiology》2005,51(7):605-612
Through gas chromatography - mass spectrometry, the presence of oxylipins, mainly 3-hydroxy 9:1 and 3-hydroxy 10:1, was detected in Saccharomycopsis fermentans, Saccharomycopsis javanensis, and Saccharomycopsis vini. The distribution of these compounds was mapped using immunofluorescence microscopy, and they were found to be closely associated with the surfaces of aggregating ascospores. 相似文献
11.
Myxotrichum ochraceum var.frigidum, a new variety ofMyxotrichum, is described and illustrated from the material from Japanese soil. It is morphologically characterized by dull green to black ascomata with a yellow-orange centrum, peridium consisting of a fragile hyphal network, peridial hyphae with internal coiled branches and short spine-like appendages, pale yellow fusiform striate ascospores, and the absence of an anamorph. The new variety primarily differs from the type variety in the absence of elongate appendages. A key to all accepted species of the genus is revised. 相似文献
12.
The development of the cephalothecoid peridium of Aporothielavia leptoderma was examined using light and electron microscopy. Early stages in ascoma initiation were consistent with previous reports for other species in the Chaetomiaceae. However, as young cleistothecia increased in size, clusters of peridial cells in the outer textura angularis elongated in a radial pattern around a central cell or cell cluster to form rosettes of relatively thick-walled segments that marked the central areas of incipient cephalothecoid plates. The external flank along median portions of the radial cells became thin walled and swelled outwards so that each plate became concave and was separated from adjacent plates by a more or less circular to polygonal ridge of knuckle-shaped swellings. When dry, mature peridia split apart along some of the ridges demarcating individual plates but an internal mechanism for liberating ascospores from the confines of the ascoma was not observed. Physical disturbance of mature cleistothecia by beetles, when enclosed together in a Petri dish, shattered the peridia, liberating the ascospores. Smaller insects were unable to cause disarticulation of the cephalothecoid plates. Because of the presence of an apical germ pore in the ascospores and morphological similarity to Chaetomidium arxii, the new combination Chaetomidium leptoderma (syn. Thielavia leptoderma) comb. nov. is proposed. 相似文献
13.
Yoshikazu Horie Dong Mei Li Toshimitu Fukiharu Ruoyu Li Paride Abliz Kazuko Nishimura Duan Li Wang 《Mycoscience》1998,39(2):161-165
Emericella appendiculata, a new species isolated from soil of the Pamire Plateau, is described and illustrated. It is characterized by grayish green
non-ostiolate ascomata surrounded by a thick layer of hülle cells, membranaceous peridium, prototunicate asci, violet-brown,
lenticular ascospores which are ornamented by two stellate equatorial crests, capitate convex surfaces, and long filiform
appendages, and anAspergillus anamorph with biseriate conidiogenous cells. 相似文献
14.
Nannizziopsis mirabilis, isolated from a soil sample collected from New Jersey, USA, is described as a new species. The ascomata are white to pale yellow, with a peridium of a network of loosely interwoven hyphae and simple, more or less straight, clavate appendages. The ascospores are hyaline, globose to subglobose, and ornamented with spiral bands or sometimes polygonal pits. The associated anamorph is assignable to the form genusChrysosporium. 相似文献
15.
Bareetseng AS Kock JL Pohl CH Pretorius EE Botes PJ Van Wyk PW Nigam S 《Canadian journal of microbiology》2005,51(1):99-103
Immunofluorescence microscopy exposed the presence of novel 3-hydroxy oxylipins on the surfaces of aggregated hat-shaped ascospores of Ascoidea africana. These compounds were confirmed by gas chromatography - mass spectrometry analysis. Only the complete structure of a novel 3-hydroxy 10:1 could be determined. 相似文献
16.
Yoshikazu Horie Paride Abliz Yan Hui Toshimitsu Fukiharu Kazuko Nishimura Dong Mei Li Ruoyu Li 《Mycoscience》2000,41(2):183-187
Emericella qinqixianii, a new species isolated from desert soil from Sanchakou, Aksu, Qiemo, Yuli, Yutian, and the Taklimakan desert 100 km inland
from Minfeng, Xinjiang Province, China, is described and illustrated. It is characterized by grayish yellow to olive brown,
non-ostiolate ascomata surrounded by hyaline to pale yellowish brown hülle cells, membranaceous peridium, prototunicate asci,
and violet-brown, lenticular ascospores with two equatorial crests, smooth convex surfaces, and long filiform appendages.
It hasAspergillus anamorph with biseriate aspergilla. 相似文献
17.
A new species of Cataractispora, C. receptaculorum, is described from freshwater habitats. This species is characterized by triseptate verruculose ascospores and polar appendages that unfurl in water. The ascospores lack polar chambers that enclose the appendages as in C. bipolaris and C. viscosa. An ultrastructural study of this species revealed that the ascus wall and apical ring of this species is typical of the Annulatascaceae, while the ascospore wall with verruculose ornamentations and the ontogeny of the ascospore polar appendages are similar to the other species of Cataractispora. Cataractispora receptaculorum is illustrated with interference light, scanning and transmission electron micrographs. 相似文献
18.
Mohamed Ahmed Abdel-Wahab Ka Lai Pang Hassan Mohamed El-Sharouny E. B. Gareth Jones 《Mycoscience》2001,42(3):255-260
Halosarpheia unicellularis sp. nov. is described from decayed attached wood ofAvicennia marina collected from two mangrove sites in the Red Sea, Egypt. The ascomycete is compared with other marine taxa having ascospores
with polar unfurling appendages. It is also compared with other marine genera with oval, round or ellipsoid hyaline, unicellular
ascospores, but for which appendages have not been reported. Molecular data confirms the assignment of the fungus toHalosarpheia which forms a clade with the type speciesHalosarpheia fibrosa. 相似文献
19.
Spiromastix saturnispora, isolated from a soil sample collected from central Java in Indonesia, is described and illustrated as a new species. The new species was compared with the type ofSpiromastix, S. warcupii, and is similar in having brownish ascomata with a peridium of a loose network of delicate hyphae, peridial appendages which are curved in the manner of a scimitar and never completely coiled, and the absence of an anamorph. The ascospores ofS. saturnispora are characterized as large oblate, 3.2–4.8 × 2.5–3µm, punctate, and with an equatorial rim, which serves to distinguish the species fromS. warcupii and other known species. 相似文献
20.
The monarch butterfly, Danaus plexippus L., oviposits mainly on plants in the Asclepiadaceae, particularly within the genus Asclepias. We studied postalightment oviposition behavior of monarch females on three host species—Asclepias curassavica, A. incarnata , and A. tuberosa. After landing on the host, they used their forelegs, midlegs, and antennae to assess plant suitability. When these appendages were examined by scanning electron microscopy, contact chemoreceptor sensilla were found. In choice tests, A. incarnata was most preferred, while A. tuberosa was least preferred. However, the use of appendages varied for the different host species. Antennae were most frequently used during post-alightment behavior on A. curassavica, whereas forelegs were used more often on A. incarnata, and all three appendages were used extensively on A. tuberosa. Use of the midlegs was generally followed by use of the antennae. Tasting with either forelegs or antennae apparently may lead to egg laying on some host species. Rupture of the plant surface by midleg spines was also observed. The behavior and host preference of individual females varied significantly and may reflect differences in receptor sensitivity. 相似文献