Ultrastructural Changes During Germination of Ascospores of Neurospora tetrasperma

Lowry, Robert J.; Sussman, Alfred S.

doi:10.1099/00221287-51-3-403

Cited by 51 publications

(23 citation statements)

References 10 publications

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“…S y n t hes i s of end o p 1 a smic reti c u 1 um d u r i n g spore ge rin i n a t i on seems to be a widespread feature in fungi and may be correlated with the increase in synthetic activity of the spores (Lowry & Sussman, 1968;Fletcher, 1971 ;Gull & Trinci, 1971 ;Florance, Denison & Allen, 1972). The endoplasmic reticulum in Trichoderma wa\ in the form of sheets.…”

Section: Germinationmentioning

confidence: 99%

Biogenesis of Mitochondria in Trichoderma viride: Structural Changes in Mitochondria and Other Spore Constituents during Conidium Maturation and Germination

Rosen

Edelman

Galun

et al. 1974

Journal of General Microbiology

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Section: Germinationmentioning

confidence: 99%

Biogenesis of Mitochondria in Trichoderma viride: Structural Changes in Mitochondria and Other Spore Constituents during Conidium Maturation and Germination

Rosen

Edelman

Galun

et al. 1974

Journal of General Microbiology

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“…In early germlings most of the mitochondria are elongate ra.ther than spherical. These changes are apparently common during the course of development in fungi because they are known to occur in conidia of Botrytis cinerea (Hawker & Hendy,i963), ascospores of Neurospora tetrasperma (Lowry & Sussman, 1968) and B. emersonii zoospores (Reichle & Fuller, I 967). Furthermore, the mitochondria are found during the encystment period dispersed and lying close to the cell membrane, suggesting that they function in cell wall synthesis during the period of mjcelial growth.…”

Section: Discussionmentioning

confidence: 99%

The Fine Structure of the Zoospores and Cysts of Allomyces macrogynus

Hill

1969

Journal of General Microbiology

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S U M M A R YZoospores and cysts of Allomyces macrogynus have been studied by electron microscopy. A membrane-bound nuclear cap filled with ribosomes surrounded a single nucleus. Mitochondria and lipid bodies were found at the periphery of the nuclear cap. The flagellum was attached close to the nucleus by two tubular structures running anteriorly along both sides of the nuclear cap. During encystment the axoneme was retracted, the nuclear cap dissected with endoplasmic reticulum and the mitochondria increased in number and started to elongate. Concentric granules and/or mitochondria were found embedded in the nuclear cap. shows the typical 9 + 2 fibrillar configuration, a kinetosome and centrioles. However, the details of nuclear-cap organization and flagellar anchorage vary from organism to organism. All are surrounded by a cell membrane not enveloped by a cell wall. Mitochondria, endoplasmic reticulum, vacuoles, vesicles and lipid bodies are structures typically found in all of these spores.This work was undertaken to determine the fine structure of Allomyces macrogynus zoospores and cysts as a preliminary to a study of sporogenesis and spore germination. Similarities and differences between these structures and closely related aquatic Phycomycetes are pointed out. METHODSThe organism was grown in Petri dishes filled with Emerson (1958) YpSs agar for 5 days at room temperature in complete darkness. The plates were flooded with sterile tap water and allowed to stand for 45 min., after which the zoospores were in heavy concentration. The spores began to emerge from sporangia about 15-20 min. after being flooded. The time from flooding the plates to fixation was about 55 min. Spores prepared in this manner represented a heterogeneous population in which motile spores and those that had encysted were always present, although there were fewer encysted spores than motile spores.

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“…) Ces. & De Not., while Lowry and Sussman (1968) have illustrated changes during germination of ascospores of Neurospora tetrasperma Shear & B. O. Dodge. Detailed ultrastructural information on the cytoplasm, organisation of the ascospore, hyphal structure and mucilage production during germination is not available for marine fungi. Hyde et al (1994) have illustrated the ultrastructure of ungerminated ascospores of Halosphaeria appendiculata Linder, and Hyde et al (1986) illustrated mucilage production and mucilage mediated attachment by germ tubes of several marine fungi at the SEM level.…”

mentioning

confidence: 98%

Ultrastructure of germination and mucilage production in Halosphaeria appendiculata (Halosphaeriaceae)

1997

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The germination of ascospores of the marine fungus Halosphaeria appendiculata was investigated with transmission electron microscopy. Prior to germination, settled ascospores became surrounded by a fibro-granular layer, Small, membrane-bounded vesicles and larger electron-dense membrane-bounded vesicles aggregated at the site of germ tube formation where the plasmalemma adjacent to the aggregation was convoluted. The vesicles appeared to fuse with the plasmalemma, releasing their contents. Enzymatic digestion of the spore wall probably occurred at the time of germ tube emergence. After the nucleus had migrated into the newly formed germ tube, a septum was formed to delimit the germ tube from the ascospore. The growing germ tube can be divided into 3 morphological regions, namely the apical, sub-apical and vacuolated regions, and is typical of other fungi. A mucilaginous sheath was associated with the older mycelium. The germ tube displaced the polar appendage, and the ascospore, germ tube and appendage were enclosed in a mucilaginous sheath. In ascospores which subtended old germ tubes, the nucleus and lipid body became irregular in shape and the cytoplasm was more vacuolated. Microbody-like structures remained associated with the lipid throughout development, and were present in old ascospores.

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Ultrastructural Changes During Germination of Ascospores of Neurospora tetrasperma

Cited by 51 publications

References 10 publications

Biogenesis of Mitochondria in Trichoderma viride: Structural Changes in Mitochondria and Other Spore Constituents during Conidium Maturation and Germination

Biogenesis of Mitochondria in Trichoderma viride: Structural Changes in Mitochondria and Other Spore Constituents during Conidium Maturation and Germination

The Fine Structure of the Zoospores and Cysts of Allomyces macrogynus

Ultrastructure of germination and mucilage production in Halosphaeria appendiculata (Halosphaeriaceae)

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