scholarly journals Growth and Differentiation of the Golgi Apparatus in the Red Alga, Callithamnion Roseum

1974 ◽  
Vol 14 (3) ◽  
pp. 633-655
Author(s):  
EVA KONRAD HAWKINS
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Red Algae ◽  
Developmental Stages ◽  
Spore Wall ◽  
Red Alga ◽  
Wall Formation ◽  
Golgi Vesicles

The fine structure of the Golgi apparatus during development of tetrasporangia of Calli-thamnion roseum is described. Dictyosomes and associated vesicles of 4 developmental stages of sporangia are examined. The wall of sporangia exhibits a heretofore unseen cuticle in red algae. Development of the spore wall and a new plasma membrane around spores occurs through fusion of adjacent Golgi vesicles along the periphery of cells. Observations are discussed in relation to wall formation and expansion of tetrads and in comparison with other work on growth and differentiation of the Golgi apparatus.

scholarly journals The fine structure produced in cells by primary fixatives 2. Potassium dichromate

1965 ◽  
Vol s3-106 (73) ◽  
pp. 15-21
Author(s):  
JOHN R. BAKER
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Nuclear Membrane ◽  
Osmium Tetroxide ◽  
Potassium Dichromate ◽  
Potassium Dichromate Solution ◽  
Zymogen Granules ◽  
Mouse Pancreas

The exocrine cells of the mouse pancreas were fixed in potassium dichromate solution, embedded in araldite or other suitable medium, and examined by electron microscopy. Almost every part of these cells is seriously distorted or destroyed by this fixative. The ergastoplasm is generally unrecognizable, the mitochondria and zymogen granules are seldom visible, and no sign of the plasma membrane, microvilli, or Golgi apparatus is seen. The contents of the nucleus are profoundly rearranged. It is seen to contain a large, dark, irregularly shaped, finely granular object; the evidence suggests that this consists of coagulated histone. The sole constituent of the cell that is well fixed is the inner nuclear membrane. The destructive properties of potassium dichromate are much mitigated when it is mixed in suitable proportions with osmium tetroxide or formaldehyde.

Ultrastructure and molecular phylogeny of Pleistophora hyphessobryconis (Microsporidia) infecting hybrid jundiara (Leiarius marmoratus × Pseudoplatystoma reticulatum) in a Brazilian aquaculture facility

Parasitology ◽  
2015 ◽  
Vol 143 (1) ◽  
pp. 41-49 ◽  
Author(s):  
ANDREW D. WINTERS ◽  
INGEBORG M. LANGOHR ◽  
MARCOS DE A. SOUZA ◽  
EDSON M. COLODEL ◽  
MAURO P. SOARES ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Developmental Stages ◽  
Polar Filament ◽  
Inflammatory Cells ◽  
Spore Wall ◽  
Ornamental Fish ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Dense Mass

SUMMARYA microsporidian infecting the skeletal muscle of hybrid jundiara (Leiarius marmoratus × Pseudoplatystoma reticulatum) in a commercial aquaculture facility in Brazil is described. Affected fish exhibited massive infections in the skeletal muscle that were characterized by large opaque foci throughout the affected fillets. Histologically, skeletal muscle was replaced by inflammatory cells and masses of microsporidial developmental stages. Generally pyriform spores had a wrinkled bi-layer spore wall and measured 4·0 × 6·0 µm. Multinucleate meronts surrounded by a simple plasma membrane were observed. The polar filament had an external membrane and a central electron dense mass. The development of sporoblasts within a sporophorous vesicle appeared synchronized. Ultrastructural observations and molecular analysis of 16S rDNA sequences revealed that the microsporidian was Pleistophora hyphessobryconis. This study is the first report of a P. hyphessobryconis infection in a non-ornamental fish.

Ascocarp ultrastructure of Herpomyces sp. (Laboulbeniales) and its phylogenetic implications

1977 ◽  
Vol 55 (15) ◽  
pp. 2015-2032 ◽  
Author(s):  
Terry W. Hill
Keyword(s):  
Red Algae ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Spore Wall ◽  
Wall Formation ◽  
Pole Body ◽  
Phylogenetic Implications ◽  
Close Relationship

The asci of Herpomyces sp. (Laboulbeniales) compose a parenchymatous tissue produced by progressive cleavage of three or four meristematic ascogenous cells attached in the base of the ascocarp. Ascospores are delimited by membranes derived from an ascus vesicle, and the spore wall forms between paired prospore membranes. Dilated cisternae and epiplasmic membranes are associated with wall formation. While ascospores are developing, asci are displaced apically, their passage apparently lubricated by a matrix secreted by the peridial cells.The presence of an ascomycetous spindle pole body, septal pore with Woronin bodies, ascus vesicle, and dilated Golgi-like cisternae indicates a close relationship between Herpomyces sp. and the filamentous Ascomycetes while providing no support for theories maintaining a close relationship between Laboulbeniales and the red algae.

Fine structure of the spores of Minchinia chitonis (Lankester, 1885) Labbé, 1896 (Sporozoa: Haplosporida), a parasite of the chiton, Lepidochitona cinereus

Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 169-176 ◽  
Author(s):  
S. J. Ball
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Morphological Study ◽  
Smooth Endoplasmic Reticulum ◽  
Spore Wall ◽  
Single Nucleus

SUMMARYA morphological study of the fine structure of the spores of Minchinia chitonis, a haplosporidian parasite of the chiton, Lepidochitona cinereus, is described. The spores contained a single nucleus, mitochondria, haplosporosomes, smooth endoplasmic reticulum, ribosomes and a large spherule (presumed Golgi apparatus). The spore wall was discontinuous at the spherule end, forming an opening covered by a lid which rested on a circumscribed flange. The flange of the spore wall and the lid were continuous in only one area which served as a hinge. The entire spore was encapsulated by epispore cytoplasm bounded by a strengthened membrane and extended to form 2 long projections, one at either end.

scholarly journals CHROMATOPHORE DEVELOPMENT, PITS, AND OTHER FINE STRUCTURE IN THE RED ALGA, LOMENTARIA BAILEYANA (HARV.) FARLOW

1962 ◽  
Vol 12 (3) ◽  
pp. 553-569 ◽  
Author(s):  
G. Benjamin Bouck
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Higher Plants ◽  
Red Alga ◽  
Cellular Structures ◽  
Secretory Function ◽  
Thin Sections ◽  
Floridean Starch ◽  
Oriented Parallel

Thin sections of the red alga, Lomentaria baileyana, a tubular member of the Rhodymeniales, were examined after permanganate fixation and Araldite embedding. Many of the cellular structures in Lomentaria were found to be similar to analogous structures in animals and higher plants. However, in the walls between cells are modified areas generally known as pits which are unique to the higher orders of red algae (Florideae). In this study the pits were found to consist of a plug-like structure surrounded by an uninterrupted membrane apparently continuous with the plasma membrane. Examination of the chromatophore revealed a characteristic limiting membrane, a relatively sparse distribution of plates, no grana, and a single disc apparently oriented parallel to the limiting membrane. In addition to their origin from non-lamellate proplastids, chromatophores were found capable of division by simple constriction. Floridean starch grains were observed outside the chromatophore and the possibility of an association of the first formed grains with portions of the endoplasmic reticulum is considered. Gland cells seem to have a high proportion of Golgi components (dictyosomes), and are believed to have some kind of secretory function. Many of the Golgi vesicles seem to open on the wall and presumably discharge their contents.

scholarly journals Mechanism of glycosylation in the Golgi apparatus.

1983 ◽  
Vol 31 (8) ◽  
pp. 1033-1040 ◽  
Author(s):  
B Fleischer
Keyword(s):  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Serum Proteins ◽  
Membrane Vesicles ◽  
Uridine Diphosphate ◽  
Golgi Membrane ◽  
Membrane Glycoproteins ◽  
Plasma Membrane Vesicles ◽  
Golgi Vesicles

A major role of the Golgi apparatus in liver is the terminal glycosylation of secreted serum proteins and of plasma membrane glycoproteins. Galactosyltransferase is a membrane-bound Golgi enzyme that transfers galactose directly from uridine diphosphogalactose (UDP-Gal) to terminal N-acetylglucosamine groups of N-asparagine-linked glycoproteins during secretion. Sialytransferase then transfers sialic acid from cytidine monophosphosialic acid (CMP-NAN) to the newly added terminal galactose of the glycoprotein. In the cell, the transfer reaction must occur on the lumen side of the Golgi membrane. UDP-Gal is synthesized mainly in the cytoplasm and CMP-NAN is synthesized in the nucleus in liver. An important question for understanding the mechanism is, how do these nucleotide sugars gain access to the transferases? A second question involves uridine diphosphate (UDP), a highly inhibitory product of galactosyltransferase. How is UDP removed from the lumen of the Golgi fast enough to prevent product inhibition of the galactosyltransferase? We have shown that isolated Golgi, although vesiculated, retains its original orientation. The vesicles are oriented with greater than 90% of both galactosyltransferase and sialyl-transferase on the luminal side of the vesicles. Using intact vesicles, we can show that UDP-Gal is taken up via a saturable carrier system present in the Golgi membrane. During galactosylation in vitro, UDP formed in the lumen of Golgi vesicles is rapidly converted to UMP by a nucleoside diphosphatase in the lumen. Uridine monophosphate, which is much less inhibitory to the galactosyltransferase than UDP, is then transported out of the lumen by a second carrier and is broken down further to uridine by 5'-nucleotidase on the cytoplasmic side of the Golgi vesicles. The transport of nucleotides appears unique to the Golgi membranes, since neither rough endoplasmic reticulum nor plasma membrane vesicles from rat liver accumulate these nucleotides.

Ultrastructure of carposporogenesis in the red alga Cryptopleura ruprechtiana (Delesseriaceae: Ceramiales: Rhodophyta)

2004 ◽  
Vol 84 (4) ◽  
pp. 689-694 ◽  
Author(s):  
Stylianos G. Delivopoulos
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Developmental Stages ◽  
Red Alga ◽  
Starch Granules ◽  
Large Nucleus ◽  
Wall Formation ◽  
Floridean Starch

The ultrastructure of carpospore differentiation for the red alga Cryptopleura ruprechtiana is described. Carposporogenesis proceeds through three developmental stages. After cleaving from multinucleate gonimoblast initials the terminal gonimoblast cells differentiate to produce carpospores. These young carpospores possess a large nucleus and numerous proplastids with a peripheral thylakoid. During the later stages of young carpospores starch begins to polymerize. Mucilage is formed within dilating concentric membrane bodies, thus forming mucilage sacs. The latter, subsequently, release their contents initiating carpospore wall formation. Intermediate-aged carpospores have more plastids which develop their internal thylakoid system. The endoplasmic reticulum produces granular cored vesicles. Mature carpospores have numerous fully developed plastids, large floridean starch granules and fibrous vacuoles. Curved dictyosomes produce cored vesicles and adhesive vesicles. The nuclear envelope is crenulated and a two-layered wall surrounds the mature carpospore.

Golgi Apparatus and Melanogenesis: Ultrastructural Study of a Human Cellular Blue Nevus (Melanocytoma)

1973 ◽  
Vol 31 ◽  
pp. 380-381
Author(s):  
S.R. Allegra
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Ultrastructural Study ◽  
The Other ◽  
Blue Nevus ◽  
Normal Complement ◽  
Golgi Vesicles ◽  
Golgi System ◽  
The Subject ◽  
Cellular Blue Nevus

The respective roles of the ribo somes, endoplasmic reticulum, Golgi apparatus and perhaps nucleus in the synthesis and maturation of melanosomes is still the subject of some controversy. While the early melanosomes (premelanosomes) have been frequently demonstrated to originate as Golgi vesicles, it is undeniable that these structures can be formed in cells in which Golgi system is not found. This report was prompted by the findings in an essentially amelanotic human cellular blue nevus (melanocytoma) of two distinct lines of melanocytes one of which was devoid of any trace of Golgi apparatus while the other had normal complement of this organelle.

Sign in / Sign up

Export Citation Format

Share Document