Spore-like Bodies Research Articles

Arcyria versicolor of western mountains, U.S.A. (Myxomycetes: Trichiales: Trichiaceae): a morphological and taxonomic study with observations of nivicolous species

Arcyria versicolor (Trichiales: Trichiaceae) is a distinct myxomycete species described by William Phillips in 1877. The genus Arcyria dates back to Linnaeus in 1753 through the species A. denudata. Arcyria sporangia are brightly colored red, yellow, grey or white, mostly stalked, often in large groups easily seen with the naked eye. Approximately 54 species are known, many are common, and distributed worldwide. Collectors often encounter these colorful species on decaying logs as clusters of many sporangia often covering extensive areas. Arcyria versicolor, collected in the Valles Caldera National Preserve located in the Jemez Mountains of north central New Mexico, is a new record for the state. The nomenclatural history of this species is reviewed and the justification for selection of the species name versicolor is discussed. Arcyria versicolor is accepted as the valid species name and A. vitellina a synonym after examination of type specimens. Environmental parameters for coloration are discussed in general for fruiting bodies of Arcyria and more specifically for nivicolous snowbank species. Transitional stages of plasmodial color to mature fruiting body formation are described for Arcyria versicolor. More than 140 specimens of Arcyria versicolor fruiting bodies were examined with light microscopy and in part illustrated with multifocal computer stacked imaging. Higher magnifications were highlighted using scanning electron microscopy. A more complete and accurate species description is provided for Arcyria versicolor. Differences of fruiting body morphology including habit, color, dehiscence, peridial inner and outer surface features, capillitial ornamentation and size, spore color, size, and ornamentation, and stalk spore-like bodies are described and illustrated. Observation of type specimens from the type locality is illustrated, discussed, and nomenclatural evaluation given for the name selected. Mountain myxomycetes are reviewed based on the observations of T.H. Macbride and his early 1914 paper published in Mycologia. Collection data is presented that compares the dark-spored and light spored nivicolous myxomycetes in the French Alps. The history of renown collectors of nivicolous myxomycetes in western mountains of U.S.A. documents the discovery and study of this special ecological group of myxomycetes. This current paper is the first in a series from an ongoing research project entitled Myxomycetes of New Mexico.

Echinostelium novozhilovii (Echinosteliaceae, Myxomycetes), a new species from Northern Asia

A new Echinostelium novozhilovii species from Northern Asia is described and illustrated. The species was collected in the Khanty-Mansiysk Autonomous Okrug-Yugra, Russia. This new species clearly differs from the previously known species by several morphological characters. Its sporocarps have very large dimensions of 700–2500 µm tall, which exceed the dimensions of E. minutum (up to 500 µm tall). Its spores are the biggest among all known species of the Echinostelium genus with 20–25(30) µm in diameter. Its columella consists of several spore-like bodies. We present a scanning electron micrograph study of E. novozhilovii and an updated identification key for species of the Echinostelium genus worldwide, which currently includes 15 taxa. Holotype specimen of E. novozhilovii is deposited in NSK. It is the first new species for the Echinostelium genus since 1997.

Saprophytic growth of the alder rust fungus Melampsoridium hiratsukanum on artificial media

The first axenic culture of a free living saprophytic stage of the exotic rust fungus Melampsoridium hiratsukanum is reported. Colonies were obtained from one-celled, dikaryotic urediniospores on eight nutrient media out of twelve. Modified Harvey and Grasham (HG) and Schenk and Hildebrandt (HS) media HG1 and SH1 and their bovine serum albumin (BSA)-enriched derivatives gave abundant mycelial growth, but modified Murashige and Skoog (MS) QMS media and their BSA-enriched modifications performed poorly, colony growth being low on QMS-1 and QMS1+BSA, and nil on QMS-5 and QMS-6, with or without BSA. Colonies initially grew poorly when subcultured for one month in purity, but much better after re-transfer to fresh media later: presumably because only the most exploitative genotypes survived, best able to cope with an uncongenial medium. Stabilised cultures survived, and remained vegetative, but only few reproductive colonies produced spore-like bodies. Though the agarised medium remains an inhospitable environment for this biotrophic parasite, it is shown that non-living media can nevertheless sustain the growth and sporulation of this fungus outside its natural hosts and habitat. Axenic culture promises important advances in basic and applied research on this rust, leading to a better understanding of its nutrition, metabolism, diversity and pathogenicity.

FIRST REPORT OF FUNGI AND FUNGUS-LIKE ORGANISMS FROM MESOZOIC HOT SPRINGS

Herein we provide the first report of the diversity of fungi and fungus-like organisms within a Mesozoic hot spring ecosystem. The Jurassic San Agustin hot spring deposit (Patagonia, Argentina), represents only the second known Phanerozoic hot spring ecosystem with an associated microflora and contains diverse, exceptionally preserved microorganisms. Preserved propagules include flask-shaped pycnidia produced by extant coelomycetes, shield-like and nearly round thyriothecia of extant Microthyriales in the ascomycetes, variously shaped spore-like bodies representing chytrid and chytrid-like zoosporangia and other life cycle forms, and additional fungal and fungus-like remains (spores, hyphal fragments, reproductive structures) of uncertain affinity. Many of these microorganisms are associated with variously decayed organic remains, most commonly of horsetails. This expands the fungal fossil record and provides a unique opportunity to learn about the biology of Mesozoic microorganisms.

Constitutive expression of ftsZ overrides the whi developmental genes to initiate sporulation of Streptomyces coelicolor

The filamentous soil bacteria Streptomyces undergo a highly complex developmental programme. Before streptomycetes commit themselves to sporulation, distinct morphological checkpoints are passed in the aerial hyphae that are subject to multi-level control by the whi sporulation genes. Here we show that whi-independent expression of FtsZ restores sporulation to the early sporulation mutants whiA, whiB, whiG, whiH, whiI and whiJ. Viability, stress resistance and high-resolution electron microscopy underlined that viable spores were formed. However, spores from sporulation-restored whiA and whiG mutants showed defects in DNA segregation/condensation, while spores from the complemented whiB mutant had increased stress sensitivity, perhaps as a result of changes in the spore sheath. In contrast to the whi mutants, normal sporulation of ssgB null mutants—which fail to properly localise FtsZ—could not be restored by enhancing FtsZ protein levels, forming spore-like bodies that lack spore walls. Our data strongly suggest that the whi genes control a decisive event towards sporulation of streptomycetes, namely the correct timing of developmental ftsZ transcription. The biological significance may be to ensure that sporulation-specific cell division will only start once sufficient aerial mycelium biomass has been generated. Our data shed new light on the longstanding question as to how whi genes control sporulation, which has intrigued scientists for four decades.Electronic supplementary materialThe online version of this article (doi:10.1007/s10482-011-9678-7) contains supplementary material, which is available to authorized users.

Spore-Like Bodies in Some Early Paleozoic Acritarchs: Clues to Chlorococcalean Affinities

We present discoveries of internal bodies in problematic Silurian and Devonian organic-walled microfossils classified traditionally as polygonomorph, acanthomorph, sphaeromorph, and herkomorph acritarchs. These bodies are comparable with reproductive structures (auto- and/or aplanospores) of modern unicellular green algae (Chlorococcales). Our findings suggest that many of these microfossils may represent asexually reproducing (sporulating) vegetative cells of chlorococcalean algae. The presence of spore-like bodies in the studied acritarchs supports earlier suggestions, based on ultrastructural and biomarker studies, that some acritarchs can be affined with green algae.

Ultrastructure of some Cambrian palynomorphs from the Bright Angel Shale, Arizona, USA

Palynomorphs with complex resistant walls have been recovered from several Cambrian deposits in the continental United States. Those recovered from the Bright Angel Shale of Arizona typically preserve both a primary wall, and an outer envelope (synoecosporal wall) that encloses multiple spore-like bodies within. At least three distinct types of primary walls, are recognized with the TEM: 1) a unilaminate wall with a smooth inner surface and a sculptured outer surface, 2) a wall of three unornamented laminae of very uniform thickness, and, 3) a thicker wall with multiple thin, lightly-staining layers embedded in a darker matrix. This third type of primary wall bears a strong resemblance to those of certain Lower Devonian hilate cryptospore monads from the Welsh Borderlands. No extant algae produce spores with walls as thick or as complex, suggesting that these Cambrian palynomorphs were the desiccation-resistant spores of cryptogams belonging to the charophyte–embryophyte lineage. Multilaminate spore walls, which are characteristic of some extant liverworts and Paleozoic cryptospores, may have evolved via the fusion of separate, multiple laminae. This appears to be the primitive plant sporoderm type, but it may have evolved asynchronously with respect to the evolution of the embryophytic development of the sporophyte in land plants.

Enumeration and Characterization of Iron(III)-ReducingMicrobial Communities from Acidic Subsurface Sediments ContaminatedwithUranium(VI)

Iron(III)-reducing bacteria have been demonstrated to rapidly catalyze the reduction and immobilization of uranium(VI) from contaminated subsurface sediments. Thus, these organisms may aid in the development of bioremediation strategies for uranium contamination, which is prevalent in acidic subsurface sediments at U.S. government facilities. Iron(III)-reducing enrichment cultures were initiated from pristine and contaminated (high in uranium, nitrate; low pH) subsurface sediments at pH 7 and pH 4 to 5. Enumeration of Fe(III)-reducing bacteria yielded cell counts of up to 240 cells ml(-1) for the contaminated and background sediments at both pHs with a range of different carbon sources (glycerol, acetate, lactate, and glucose). In enrichments where nitrate contamination was removed from the sediment by washing, MPN counts of Fe(III)-reducing bacteria increased substantially. Sediments of lower pH typically yielded lower counts of Fe(III)-reducing bacteria in lactate- and acetate-amended enrichments, but higher counts were observed when glucose was used as an electron donor in acidic enrichments. Phylogenetic analysis of 16S rRNA gene sequences extracted from the highest positive MPN dilutions revealed that the predominant members of Fe(III)-reducing consortia from background sediments were closely related to members of the Geobacteraceae family, whereas a recently characterized Fe(III) reducer (Anaeromyxobacter sp.) and organisms not previously shown to reduce Fe(III) (Paenibacillus and Brevibacillus spp.) predominated in the Fe(III)-reducing consortia of contaminated sediments. Analysis of enrichment cultures by terminal restriction fragment length polymorphism (T-RFLP) strongly supported the cloning and sequencing results. Dominant members of the Fe(III)-reducing consortia were observed to be stable over several enrichment culture transfers by T-RFLP in conjunction with measurements of Fe(III) reduction activity and carbon substrate utilization. Enrichment cultures from contaminated sites were also shown to rapidly reduce millimolar amounts of U(VI) in comparison to killed controls. With DNA extracted directly from subsurface sediments, quantitative analysis of 16S rRNA gene sequences with MPN-PCR indicated that Geobacteraceae sequences were more abundant in pristine compared to contaminated environments,whereas Anaeromyxobacter sequences were more abundant in contaminated sediments. Thus, results from a combination of cultivation-based and cultivation-independent approaches indicate that the abundance/community composition of Fe(III)-reducing consortia in subsurface sediments is dependent upon geochemical parameters (pH, nitrate concentration) and that microorganisms capable of producing spores (gram positive) or spore-like bodies (Anaeromyxobacter) were representative of acidic subsurface environments.

The formation of spores by metamorphosed basidia in Mycocalia and Scleroderma

The development of the peridioles of a Mycocalia sp., and the primordia of Scleroderma verrucosum and S. areolatum, has been studied, particularly in view of the presence of metamorphosed basidia. In the Mycocalia sp. and S. verrucosum spore-like bodies were formed exclusively by transformation of whole basidia. The ontogeny of S. verrucosum has been compared with that of S. areolatum. The structure of the exoperidium of S. verrucosum is much more complicated: hyphal knots play an important part in its construction. The processes giving rise to the exoperidium may be homologous with those constituting universal veils in Agaricales.

Electron microscopic examination of sporulation-deficient mutants of the fission yeast Schizosaccharomyces pombe.

A homothallic haploid strain of the fission yeast Schizosaccharomyces pombe initiates sexual reproduction (mating, meiosis and sporulation) in nitrogen-free sporulation medium. Cellular fine structures of eleven sporulation-deficient mutants (spo2, spo3, spo4, spo5, spo6, spo13, spo14, spo15, spo18, spo19 and spo20) of S. pombe in sporulation medium were examined by serial section-electron microscopy. The striking features of these spo mutants were: 1) the disappearance of the spindle pole bodies (SPBs) after the second meiotic division, and 2) the accumulation of unorganized structures. Based on histochemical staining, these structures were presumably unorganized spore wall precursors. In some mutants (spo3, spo5, spo6, spo19 and spo20), diploid zygotes contained four spore-like bodies which had walls similar to complete spore walls but failed to enclose any nuclei. After completion of the second meiotic division the nuclei were abnormally distributed in zygotic diploid cells. In the spo5, spo13, spo14, spo15 and spo19 mutants, the nuclei remained attached to each other. In spo5 and spo19, the inner membrane of the nuclear envelope was separated, but its outer membrane was shared by two sister nuclei. These observations suggest that the spo+ gene products play important roles in spatial and temporal organization of cellular structures during ascospore development.

Kathistes, a new genus of pleomorphic ascomycetes

The genus Kathistes is described to accomodate two new species, K. calyculata and K. analemmoides, and an existing one based on Pyxidiophora fimbriata Barrasa & Moreno. All three species are coprophilous and produce transversely septate ascospores in long-necked perithecia. Ascospore germination occurs by the production of budding yeast cells. Sporelike bodies, termed sporidiolae, are produced in spherical structures resembling the perithecia called sporidiomata. Similar genera and species are discussed and contrasted by a dichotomous key. Kathistes species do not appear to be closely related to other ascomycetes and are assigned to a new family Kathistaceae.

Sem Studies on Operculum Structure in the Myxomycete Trichia crateriformis

Scanning electron microscope studies have been conducted on the operculum of sporangia of Trichia crateriformis and its structure has been compared with that of other operculate Myxomycetes. The operculum of T. crateriformis consists of a single layer of spore-like bodies that have cell walls ornamented with warty excresences similar to those of the spores. It adjoins the membranous peridium of the sporangium in a transition region which constitutes the dehiscence zone. In other taxa with operculate sporophores examined the operculum is membranous and has a structure generally similar to that of its associated peridium. The type of operculum in T. crateriformis may be unique for the Myxomycetes.

SEM Studies on Operculum Structure in the Myxomycete Trichia Crateriformis

Scanning electron microscope studies have been conducted on the operculum of sporangia of Trichia crateriformis and its structure has been compared with that of other operculate Myxomycetes. The operculum of T. crateriformis consists of a single layer of sporelike bodies that have cell walls ornamented with warty excresences similar to those of the spores. It adjoins the membranous peridium of the sporangium in a transition region which constitutes the dehiscence zone. In other taxa with operculate sporophores examined the operculum is membranous and has a structure generally similar to that of its associated peridium. The type of operculum in T. crateriformis may be unique for the Myxomycetes. Several species of Myxomycetes form sporangia furnished with a well-defined operculum. Species exhibiting this characteristic are Metatrichia vesparium (Batsch) Nann-Brem., certain species of Craterium and Licea, Perichaena depressa Libert, and Trichia crateriformis Martin. During the course of some scanning electron microscope (SEM) studies of types of authenticated specimens of taxa in the Trichiaceae, we observed that the operculum of the sporangium of T. crateriformis is strikingly different in structure from that of its contiguous peridial wall. The T. crateriformis operculum was noted to consist of discrete spore-like units with ornamented wall surfaces similar to those of the spores. A report on this apparently unique type of operculum structure is presented in this communication.

Parasitism on Ordovician Chitinozoa

Borings are common in chitinozoans. They are cylindrical or conical, widening towards the outer surface of the vesicle wall. It is suggested that the cylindrical borings were probably caused by bacteria. Actinomycota and lower Fungi including at least Chytridiomycota, and the conical borings mainly by chytridia. Two types of spore-like bodies, operculate and non-operculate, have been found in situ on two chitinozoan species. The spore-like bodies are of about the same size as the supposed boring organisms in chitinozoans but are never found in association with the borings. They are interpreted as cysts of ectoparasitic nannoorganisms that resemble ciliates and amoebae, and their possible use for determining the biochemical composition of the chitinozoans is briefly discussed.

Electron microscopy of the L-cycle in Bacillus licheniformis var. Endoparasiticus (Benedek).

Electronmicrographs of sections show that the L-phases of Bacillus licheniformis var. endoparasiticus (Benedek) simulate the various types of micro-organism described by previous workers as associated with ostensibly noninfective conditions, notably cancer and arthritis; e.g., mycoplasmas, mycobacteria, corynebacteria and actinomycetes. The stages of the L-cycle, from spheroplasts through smaller and larger 'diphtheroid' bacteria to the fully reverted sporogenous bacillus, differ from one another mainly in their degree of reconstitution of the cell envelopes. Occurrence in 'diphtheroids' of nonresistant, cell-wall-deficient spore-like bodies, confirms their relationship with the true sporing bacillus stage. Large, swollen forms appear to be mother cells of minute stages.

Axenic culture of two rust fungi, Puccinia coronata f. sp. avenae and P. recondita f. sp. tritici.

Urediniospores of Puccinia coronata f. sp. avenae race 367 and P. recondite f. sp. tritici race 45 were respectively cultured on an artificial medium. Urediniospores free of contaminating microorganisms were obtained by aseptic leaf culture. After the urediniospores were separately seeded on the medium, both rust fungi grew well and then formed white macroscopic colonies which had abundant aerial hyphae. About 1.5-2 months after inoculation part of the colonies changed from white to dark brown. Microscopic examination showed that spore-like bodies similar in morphology to urediniospores and teliospores were formed around the stroma. In the culture of P. coronata f. sp. avenae, teliospore-like bodies did not show a crown on top of the spores.

Notes concerning the Spore-like Bodies in Myxomycetes

Notes concerning the Spore-like Bodies in Myxomycetes

Ultraviolet sensitivity and photoproducts in spore-like bodies of an excision-repair-deficient and dipicolinic-acid-less strain of Bacillus subtilis.

Bacillus subtilis strain UVS-42DPA is defective in both excision-repair capability and dipicolonic acid(DPA)accumulation. In sporulation medium, it forms spore-like bodies, which are sensitive to ultraviolet light (UV) as the vegetative cells and produce mostly cyclobutane dimers instead of "spore photoproduct" upon UV irradiation. The results suggest that the drastic change in the photochemical reactivity of DNA during sporulation might be induced and(or) maintained by the accumulation of DPA.

Use of Immunofluorescence Staining in Kerion

We describe two cases of kerion caused by Trichophyton rebrum and Microsporum gypseum. In the histological sections, a PAS stain revealed a small number of hypha-like rods and spore-like round bodies in the dermis of patient 1. Except for some clusters of PAS-positive materials, no definite fungal elements were observed in the dermis of patient 1, whereas a considerable number of hyphae were demonstrated within a hair shaft. Immunofluorescence staining, using fluorescein-labeled T mentagrophytes antiserum, disclosed the presence of fungal antigens, not only within a hair shaft, but also in the inflammatory infiltrate in the dermis of both patients.

Ecology of Endogone in Lake Huron sand dunes

Grasses and herbs in the sand dunes of the eastern shores of Lake Huron were heavily colonized by the endomycorrhizal fungus Endogone. The fungus produced an extensive external mycelium in the dune sand. Numerous sand grains were firmly bound to the external mycelium, which was of structural importance in sand aggregates and was implicated as an important factor in dune stabilization. Sand aggregates constituted about 5 to 9% of the dry weight of sand collected from the surface 30 cm of the dunes. The weight of sand aggregates per kilogram of dune sand increased from 0.9 g to 25 g and 127 g after one and two crops, respectively, of mycorrhizal Phaseolus vulgaris L. grown in pots in a controlled environment. The increased aggregation was attributed largely to the binding of sand grains to a proliferated mycelium of Endogone. Organic fragments in the dune sand were colonized frequently by Endogone. Spores and spore-like bodies were numerous in many organic particles, which were sources of viable inoculum of Endogone. Five types of Endogone spores were found in the dune sand.