LOCALIZATION OF RUMEN WALL-ADHERENT UREOLYTIC BACTERIA

1984 ◽  
Vol 64 (5) ◽  
pp. 60-61 ◽  
Author(s):  
R. J. C. McLEAN ◽  
J. W. COSTERTON ◽  
K.-J. CHENG
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Histochemical Technique ◽  
Tissue Samples ◽  
Associated Bacteria ◽  
Transmission Electron ◽  
Ureolytic Bacteria

Treatment of rumen tissue samples with a newly developed histochemical technique for urease localization resulted in an electron dense reaction product deposition in several wall-associated bacteria. This represents the first instance in which ureolytic rumen wall-associated bacteria can be identified with transmission electron microscopy. Key words: Histochemical, rumen, urease, localization

Ultrastructural and cytological observations of apothecial tissues of Geopyxis carbonaria (Pezizales, Ascomycetes)

1990 ◽  
Vol 68 (2) ◽  
pp. 243-257 ◽  
Author(s):  
James W. Kimbrough ◽  
Jack L. Gibson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Mother Cell ◽  
Secondary Wall ◽  
Cell Stage ◽  
Wall Structures ◽  
Transmission Electron ◽  
Secondary Wall Formation ◽  
Characteristic Features

Cytological observations are made on apothecial tissues of Geopyxis carbonaria, using transmission electron microscopy. Characteristic features of both the medullary and ectal excipula are examined. Changes in ascus apex and wall structures are examined during ascus ontogeny, especially in relation to operculum position and structure. Ultrastructure of septum configuration is observed and compared in the excipulum, ascogenous hyphae, paraphyses, and at the base of young asci. Ascosporogenesis is observed from the ascus mother cell stage and initial spore delimitation until secondary wall formation. The cytological and ultrastructural observations on this species are discussed in relation to their possible taxonomic or phylogenetic value. Key words: ascosporogenesis, Discomycetes, ascospore ultrastructure, septal ultrastructure, cytochemistry.

Sporophytes, megaspores, and massulae of Azolla stanleyi from the Paleocene Joffre Bridge locality, Alberta

1994 ◽  
Vol 72 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Georgia L. Hoffman ◽  
Ruth A. Stockey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Red Deer ◽  
The Other ◽  
Evolutionary Trends ◽  
Reproductive Structures ◽  
Transmission Electron ◽  
New Material

Several hundred vegetative and fertile specimens of Azolla Lam. have been recovered from the Paleocene Paskapoo Formation at the Joffre Bridge locality (Middle Tiffanian (Ti3) age) near Red Deer, Alberta. The spore complexes closely resemble those of the Paleocene A. stanleyi Jain & Hall, and the vegetative material is referred to that species. The specimens are unusually complete in that the remains of the fragile sporophyte are preserved, commonly with reproductive structures in place. Plants reaching up to 2.25 cm in length consist of alternately branched rhizomes bearing alternate, imbricate, sessile leaves. Leaves are ovate with entire margins, papillate surfaces, and a single midvein. Reproductive structures have been examined using light, scanning, and transmission electron microscopy. This new material is compared with the other Paleocene species for which sporophytes are known and discussed in terms of evolutionary trends for the genus. The specimens suggest that most of the vegetative characteristics of modern Azolla species were established by the middle Paleocene. Key words: Azolla, Salviniaceae, megaspore, massula, ultrastructure, Paleocene.

Electron microscopy study of the bacteria adherent to the rumen wall in young conventional lambs

1990 ◽  
Vol 36 (2) ◽  
pp. 140-144 ◽  
Author(s):  
Franoise Rieu ◽  
G. Fonty ◽  
Brigitte Gaillard ◽  
P. Gouet
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Epithelial Cell ◽  
Key Words ◽  
Bacterial Population ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron ◽  
Scanning Electron

The lamb rumen walls were rapidly colonized by an abundant bacterial population after birth. This colonization was examined by electron microscopy in neonatal conventional lambs. The sequence of establishment of the epimural species during the 3 weeks following birth, and the distribution of bacteria on the different sacs of the rumen, were examined by scanning electron microscopy. The population was very dense and consisted of a limited number of morphological types by 2 days after birth. Three types of rods were dominant at that time. The microflora was more complex 2 weeks later. Observations by transmission electron microscopy of desquamated epithelial cells revealed the presence of adherent bacteria that are surrounded by fibrous carbohydrate coats and sometimes partially enclosed by invaginations of the epithelial cell. Key words: rumen, lamb, microflora, scanning electron microscopy, adherence.

scholarly journals The Transillumination Possibility of Imidazole–Osmium Postfixed Tissue and Its Consequences for the Handling of Tissue Samples

2005 ◽  
Vol 11 (1) ◽  
pp. 42-45 ◽  
Author(s):  
Tilman Voigt ◽  
Wolfgang Dauber
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tissue Sample ◽  
The Other ◽  
Light Sources ◽  
Routine Procedure ◽  
Tissue Samples ◽  
Transmission Electron ◽  
The One ◽  
Point Light

Osmium postfixation is established as a routine procedure for transmission electron microscopy (TEM). On the one hand, this routine procedure leads to good results for TEM, but on the other hand results in blackened tissue samples that do not allow examination of any structures within the embedded tissue sample by a light microscope. Equivalent fixation results for TEM are achieved with imidazole–osmium postfixation, and with this postfixation method tissue is not blackened and can be transilluminated with point light sources. This allows easier recognition of histological details within tissue samples and makes it possible to screen embedded samples for appropriate ultrastructural processing. Jejunum is used to demonstrate the method.

Fine structure of the suberized cell walls in the boundary zone and necrophylactic periderm in wounded peach bark

1986 ◽  
Vol 64 (8) ◽  
pp. 1606-1610 ◽  
Author(s):  
A. R. Biggs ◽  
L. W. Stobbs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Prunus Persica ◽  
Boundary Zone ◽  
Tissue Samples ◽  
Transmission Electron ◽  
Suberin Lamellae ◽  
Zone Cell ◽  
Granular Deposit

Bark on the scaffold limbs of 6-year-old peach (Prunus persica (L.) Batsch cv. Redhaven) trees was mechanically wounded and tissue samples for ultrastructural study were taken after 6, 8, 12, and 14 days. Examination with light and fluorescence microscopy revealed lignification of boundary zone cell walls after 6 days followed by suberization of the lignified cell walls after 8 days. Necrophylactic periderm was present by day 12 and, by day 14, three to five cells of the new phellem were observed. Examination of tissues with transmission electron microscopy revealed suberin lamellae on the inner wall of boundary zone cells. These cells contained senescing cytoplasm with fragments of undifferentiated dense material that formed a thin, discontinuous granular deposit inside the suberin layer. Suberin lamellae did not occlude plasmodesmata. Cells of the new phellem were radially compressed, heavily suberized, and lacked pits or plasmodesmata.

scholarly journals Ultrastructure of sporophyte of Cladosiphon okamuranus Tokida (Ectocarpales, Phaeophyceae)

1970 ◽  
Vol 38 (2) ◽  
pp. 177-180 ◽  
Author(s):  
Qinghua Zhu ◽  
Xuecheng Zhang ◽  
KKIU Arunakumara
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Key Words ◽  
Hair Cells ◽  
Brown Algae ◽  
Lipid Bodies ◽  
Transmission Electron ◽  
Cladosiphon Okamuranus

Transmission Electron Microscopy of 35 day old culture of Cladosiphon okamuranus Tokida, revealed several chloroplasts and other organelles in each cell of assimilatory filaments. Each chloroplast possesses single pyrenoid and Lipid bodies while in hair cells, there were few chloroplasts clinging to plasma-membrane and many pathholes were seen in the cell wall. Key words: Cladosiphon okamuranus; Brown algae; Ultrastructure; Pathhole DOI: 10.3329/bjb.v38i2.5143 Bangladesh J. Bot. 38(2): 177-180, 2009 (December)  

scholarly journals Prevalence and morphological and molecular characteristics of Sarcocystis bertrami in horses in China

Parasite ◽  
2020 ◽  
Vol 27 ◽  
pp. 1
Author(s):  
Chun-Li Ma ◽  
Yu-Long Ye ◽  
Tao Wen ◽  
Zhu-Mei Huang ◽  
Jing Pan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phylogenetic Analysis ◽  
Light Microscopy ◽  
Genetic Markers ◽  
Junior Synonym ◽  
Molecular Characteristics ◽  
Tissue Samples ◽  
Transmission Electron ◽  
Considerable Confusion

Three cyst-forming Sarcocystis species have been identified in horsemeat; however, there exists considerable confusion concerning their relationships. Here, 74% (34/46) of the examined tissue samples from horses contained sarcocysts based on examination by light microscopy (LM), and the organism was identified as Sarcocystis bertrami based on cyst structure. The S. bertrami cysts were microscopic (up to 6750 μm in length) and exhibited a striated wall with 2.0–5.1 μm villar protrusions (vps) under LM. Transmission electron microscopy (TEM) observations showed that the vps were tightly packed, similar to “type 11c”. Four genetic markers (18S, 28S, ITS1 and the mitochondrial cox1 gene) of S. bertrami were sequenced and analyzed. The 28S and ITS1 sequences are the first records for Sarcocystis in horses. The newly obtained sequences of the 18S and cox1 genes both shared the highest similarities with those of S. bertrami and S. fayeri obtained from horses. Phylogenetic analysis based on the 18S, 28S and cox1 sequences revealed that S. bertrami and S. fayeri formed an independent clade within a group comprising Sarcocystis spp. from ruminants and pigs. Therefore, S. bertrami and S. fayeri are considered to represent the same species of Sarcocystis in horses, and S. fayeri is a junior synonym of Sarcocystis bertrami.

Comparison between conidial development in Sporendocladia bactrospora and Phialocephala virens

1993 ◽  
Vol 71 (7) ◽  
pp. 985-991 ◽  
Author(s):  
Marnel Mouton ◽  
Michael J. Wingfield
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fluorescence Microscopy ◽  
Key Words ◽  
Conidiogenous Cell ◽  
Secretory Vesicles ◽  
Bright Field ◽  
Transmission Electron ◽  
Building Activity ◽  
Conidial Development

Conidium development was studied and compared in Sporendocladia bactrospora (thought to resemble Chalara spp.) and in Phialocephala virens. Techniques used in the study include bright field and fluorescence microscopy, as well as scanning and transmission electron microscopy. Sporendocladia bactrospora had cylindrical conidia produced in true chains from phialidic conidiogenous cells with long cylindrical collarettes. An area of wall building activity at the base of the conidiogenous cell was characterized by secretory vesicles indicating ring wall building development. In Phialocephala virens, conidia were formed by apical wall building and distinct periclinal thickening was evident. From this study it was possible to confirm the fact that Phialocephala s.l. can clearly be divided into two distinct groups on the basis of conidium development. Key words: apical wall building, conidiogenesis, Phialocephala, ring wall building, Sporendocladia.

Mycoparasitism of teliospores of Ustilago bullata by an oomycete

1990 ◽  
Vol 68 (11) ◽  
pp. 2415-2421 ◽  
Author(s):  
Robert W. Roberson ◽  
E. S. Luttrell ◽  
Melvin S. Fuller
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Enzymatic Degradation ◽  
Spore Wall ◽  
Wall Layer ◽  
Smut Fungus ◽  
Pythium Vexans ◽  
Transmission Electron ◽  
Host Parasite

The mycoparasitism of teliospores of the smut fungus Ustilago bullata was discovered by transmission electron microscopy (TEM). Large, multinucleate chlamydospores germinated, producing hyphae that directly penetrated the walls of mature teliospores after forming an appressorium-like structure. Invagination of the exosporium at the point of penetration suggested mechanical penetration of this outer spore wall layer. The inner endosporium layer was fibrillar in appearance, with irregular electron-transparent regions suggesting enzymatic degradation. The cytoplasm and endosporium of parasitized teliospores were completely disintegrated, leaving only the spiny exosporium layer distributed throughout the sorus. Hyphae of the mycoparasite emerged from the teliospore shell, and their tips penetrated surrounding teliospores. TEM characteristics of the parasite confirmed oomycetous affinities. Pythium vexans was isolated from smutted tissue collected at the same time as tissue used for TEM observations. Pythium vexans was able to parasitize U. bullata teliospores in culture. Key words: hyperparasitism, ultrastructure, smut, Pythium, host–parasite relationships, infection.

The conidial surface ofBotrytis cinereaand several otherBotrytisspecies

1997 ◽  
Vol 75 (4) ◽  
pp. 612-617 ◽  
Author(s):  
Robert P. Doss ◽  
James K. Christian ◽  
Sandra W. Potter ◽  
Alfred H. Soeldner ◽  
Gary A. Chastagner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Botrytis Cinerea ◽  
Fungal Species ◽  
Transmission Electron ◽  
Conidial Surface ◽  
Weave Pattern ◽  
Scanning Electron

Surfaces of conidia of Botrytis cinerea Pers: Fr. and several other Botrytis species were studied using scanning electron microscopy and transmission electron microscopy with carbon–platinum replicas. The surface of dry conidia of B. cinerea was rough with numerous short (200–250 nm) protuberances. Upon hydration and redrying these protuberances disappeared. The surfaces of conidia of other Botrytis species were similar to the surface of B. cinerea. The basket-weave pattern of hydrophobin rodlets present on the surfaces of spores of many fungal species was not observed on conidia of any of the Botrytis species. Rodlets were seen when the methods employed in this study were used to examine conidia of Aspergillus nidulans (Eidam) Winter, Neurospora crassa Shear et Dodge, or Penicillium camembertii Thom:, fungal species known to possess rodlets. Key words: hydrophobicity, conidial surface, Botryotinia, electron microscopy.

Sign in / Sign up

Export Citation Format

Share Document