Rod-shaped virus-like particles in the endoplasmic reticulum ofAudouinella saviana(Acrochaetiales, Rhodophyta)

1995 ◽  
Vol 73 (12) ◽  
pp. 1974-1980 ◽  
Author(s):  
Curt M. Pueschel
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Key Words ◽  
Rough Endoplasmic Reticulum ◽  
Red Algae ◽  
Central Element ◽  
Red Alga ◽  
Photosynthetic Membranes ◽  
Virus Like Particles ◽  
Cellular Abnormalities

Rod-shaped particles, approximately 30 nm in width and 1000 nm or more in length, were found in cells of the red alga Audouinella saviana (Meneghini) Woelkerling. Parallel in orientation and hexagonally packed, these inclusions were located within dilated cisternae of rough endoplasmic reticulum. The rods consisted of an electron-dense central element surrounded by a thick-walled tube that appeared to be composed of repeating granular subunits. Although uninfected controls of the same species were not available, the morphology and substructure of the inclusions, the absence of such inclusions in other species of Audouinella, and the apparent connection of these particles with cellular abnormalities and necrosis suggest that these inclusions may be viral in nature. Among the unusual and possibly cytopathic features of cells containing particles were ropy, fibrillar structures free in the cytoplasm, corrugated mitochondrial cristae, amorphous mitochondrial inclusions, highly convoluted photosynthetic membranes, and loss of integrity of the nuclear envelope. This is the first report of the presence of possible rod-shaped virus-like particles in red algae. Key words: Acrochaetiales, Audouinella saviana, Rhodophyta, ultrastructure, virus-like particles.

scholarly journals DEVELOPMENT OF ENDOGENOUS PEROXIDASE IN FETAL RAT SUBMANDIBULAR GLAND

1973 ◽  
Vol 21 (1) ◽  
pp. 42-50 ◽  
Author(s):  
SHOHEI YAMASHINA ◽  
TIBOR BARKA
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Submandibular Gland ◽  
Rough Endoplasmic Reticulum ◽  
Peroxidase Activity ◽  
Secretory Granules ◽  
Prenatal Development ◽  
Reaction Products ◽  
Cell Type ◽  
Endogenous Peroxidase

The prenatal development of endogenous peroxidase activity in the submandibular gland of rat was investigated by means of the diaminobenzidine-H2O2 histochemical method. The submandibular gland of a 16-day-old fetus was composed of cords of uniform, undifferentiated cells which contained no secretory granules and revealed no peroxidase activity. Peroxidase activity first appeared at the 17th day of gestation in the cisternae of the rough endoplasmic reticulum and nuclear envelope in a few cells. At the 18th day of gestation cells which exhibited reaction products in the rough endoplasmic reticulum and nuclear envelope also contained secretory granules with a strong peroxidase activity. During the last days of gestation the number of peroxidase positive cells, which contained numerous secretory granules, increased. The peroxidase-containing cells are the immediate precursors of the proacinar cells of early postnatal stages. During the same time period, when the peroxidase-containing cells differentiated, a second cell type also differentiated in the cellular cords. The development of this cell type was marked by the appearance of secretory granules stainable with toluidine blue. Through the prenatal development, this cell type revealed no peroxidase activity and was identified with the terminal tubule cell of the newborn. The morphologic and cytochemical findings indicate that terminal tubule cells and proacinar cells are committed cells; the former differentiate toward 2nd order intercalated duct cells and the latter transform to mature acinar cells.

Immunocytochemical localization of wheat prolamins in the lumen of the rough endoplasmic reticulum

1991 ◽  
Vol 69 (11) ◽  
pp. 2574-2577 ◽  
Author(s):  
Hari B. Krishnan ◽  
Jerry A. White ◽  
Steven G. Pueppke
Keyword(s):  
Triticum Aestivum ◽  
Endoplasmic Reticulum ◽  
Key Words ◽  
Rough Endoplasmic Reticulum ◽  
Protein A ◽  
Triticum Aestivum L ◽  
Soluble Proteins ◽  
Immunocytochemical Localization ◽  
Specific Antibodies ◽  
Days After Anthesis

Antibodies raised against gliadins, the alcohol-soluble proteins of wheat (Triticum aestivum L.) seeds, were used to localize gliadins within the lumen of the endoplasmic reticulum. Endosperm cells at 20 days after anthesis contain extensive rough endoplasmic reticulum that is fragmented and dilated. The dilated endoplasmic reticulum encloses aggregates of proteinaceous material that reacts strongly with gliadin-specific antibodies. Key words: gliadins, immunocytochemistry, protein A – gold, rough endoplasmic reticulum, wheat.

The Role of Endoplasmic Reticulum in the Repair of Amoeba Nuclear Envelopes Damaged Microsurgically

1974 ◽  
Vol 14 (2) ◽  
pp. 421-437
Author(s):  
C. J. FLICKINGER
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Rough Endoplasmic Reticulum ◽  
Repair Process ◽  
Nuclear Membranes ◽  
Normal Configuration ◽  
Layer Characteristic ◽  
The Relationship ◽  
Coated Slide

The nuclear envelopes of amoebae were damaged microsurgically, and the fate of the lesions was studied with the electron microscope. Amoebae were placed on the surface of an agar-coated slide. Using a glass probe, the nucleus was pushed from an amoeba, damaged with a chopping motion of the probe, and reinserted into the amoeba. Cells were prepared for electron microscopy at intervals of between 10 min and 4 days after the manipulation. Nuclear envelopes studied between 10 min and 1 h after the injury displayed extensive damage, including numerous holes in the nuclear membranes. Beginning 15 min after the manipulation, pieces of rough endoplasmic reticulum intruded into the holes in the nuclear membranes. These pieces of rough endoplasmic reticulum subsequently appeared to become connected to the nuclear membranes at the margins of the holes. By 1 day following the injury, many cells had died, but the nuclear membranes were intact in those cells that survived. The elaborate fibrous lamina or honeycomb layer characteristic of the amoeba nuclear envelope was resistant to early changes after the manipulation. Patches of disorganization of the fibrous lamina were present 5 h to 1 day after injury, but the altered parts showed evidence of progress toward a return to normal configuration by 4 days after the injury. It is proposed that the rough endoplasmic reticulum participates in the repair of injury to the nuclear membranes. The similarity of this repair process to reconstitution of the nuclear envelope in telophase of mitosis is noted, and the relationship between the nuclear envelope and the rough endoplasmic reticulum is discussed.

scholarly journals Ultrastructure of mononuclear phagocytes developing in liquid bone marrow cultures. A study on peroxidatic activity

1979 ◽  
Vol 149 (1) ◽  
pp. 17-26 ◽  
Author(s):  
JWM Van Der Meer ◽  
RHJ Beelen ◽  
DM Fluitsma ◽  
R Van Furth
Keyword(s):  
Bone Marrow ◽  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Nuclear Envelope ◽  
Rough Endoplasmic Reticulum ◽  
Precursor Cells ◽  
Mononuclear Phagocytes ◽  
Peroxidatic Activity

Monoblasts, promonocytes, and macrophages in in vitro cultures of murine bone marrow were studied ultrastructurally, with special attention to peroxidatic activity. Monoblasts show peroxidatic activity in the rough endoplasmic reticulum and nuclear envelope as well as in the granules. The presence of peroxidatic activity in the Golgi apparatus could not be determined. Promonocytes have peroxidase-positive rough endoplasmic reticulum, Golgi apparatus, nuclear envelope, and granules, as previously reported. During culture, cells are formed with peroxidatic activity similar to that of monocytes or exudate macrophages (positive granules; negative Golgi apparatus, RER, and nuclear envelope); we call these cells early macrophages. In addition, transitional macrophages with both positive granules and positive RER, nuclear envelope, negative Golgi apparatus (as in exudate- resident macrophages in vivo), and mature macrophages with peroxidatic activity only in the RER and nuclear envelope (as in resident macrophages in vivo) were found. A considerable number of cells without detectable peroxidatic activity were also encountered. Our finding that macrophages with the peroxidatic pattern of monocytes (early macrophages), exudate-resident macrophages (transitional macrophages), and resident macrophages (mature macrophages), develop in vitro from proliferating precursor cells deriving from the bone marrow, demonstrates once again that resident macrophages in tissues originate from precursor cells in the bone marrow. Therefore, this conclusion can no longer be challenged on the basis of a cytochemical difference between monocytes and exudate macrophages on the one hand and resident macrophages on the other.

Fine Structure of the Cytoplasm in Salivary Glands of Simulium

1967 ◽  
Vol 2 (1) ◽  
pp. 137-144
Author(s):  
H. C. MACGREGOR ◽  
J. B. MACKIE
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Nuclear Envelope ◽  
Salivary Glands ◽  
Rough Endoplasmic Reticulum ◽  
Salivary Secretion ◽  
Septate Junction ◽  
Cell Junctions ◽  
Salivary Gland Cell ◽  
Apical Cytoplasm

The salivary glands of 3rd or 4th instar larvae of Simulium niditifrons are about 5 mm long and up to 400 µ wide. They have a capacious lumen which is normally filled with secretion. The apical (luminal) plasmalemma of the gland cells is thrown into numerous microvilli. The basal plasmalemma is usually straight but is infolded in places. The infoldings may be complex near to cell junctions. There is a thick, uniform basement membrane. Contact surfaces of adjacent cells often interdigitate. A septate junction extends inwards from the lumen for one-quarter the depth of the cells. Rough endoplasmic reticulum is distributed evenly throughout the cytoplasm. Many Golgi complexes with dark membrane-bounded granules are scattered throughout the cytoplasm. Solitary granules, often more than I µ in diameter, lie in the apical cytoplasm, especially near the apical border of the cell. These granules resemble the larger Golgi granules and the contents of the lumen. Solitary granules consisting of 2 components have been seen in various stages of passage through the cell membrane. The 2 components are present in roughly constant proportions and can be identified in the larger Golgi granules and in the secretion in the lumen. The nucleus is spherical. The nuclear envelope is smooth in the larger cells of a gland but may be folded in the smaller cells. There are 80-100 pores/µ2 of nuclear envelope. Each pore appears to have a small granule at its centre. Microtubules, about 180 Å thick, are numerous in the apical cytoplasm, particularly near the luminal border. Tubules which lie deep in the cytoplasm are flanked by a clear area 100-200 Å wide. The fine structure of a salivary gland cell of Simulium appears to indicate that the major components of the salivary secretion are synthesized in association with the ribosomes on the rough endoplasmic reticulum, concentrated in the Golgi regions, formed into secretion granules, and passed out of the cell into the lumen of the gland by reverse phagocytosis.

Zoospore ultrastructure of Olpidium cucurbitacearum (Chytridiales)

1977 ◽  
Vol 55 (24) ◽  
pp. 3063-3074 ◽  
Author(s):  
D. J. S. Barr ◽  
V. E. Hadland-Hartmann
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Transition Zone ◽  
Rough Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Flagellar Apparatus ◽  
Multivesicular Bodies ◽  
Taxonomic Relationship ◽  
Anterior Nucleus

Zoospore ultrastructure of Olpidium cucurbitacearum Barr & Dias is described. Isolates from Ontario and Japan are alike. The elliptical zoospore has an anterior nucleus partially surrounded by lobed and branched mitochondria. In the central part an interconnecting network consisting ofsmooth and rough endoplasmic reticulum, a Golgi complex, microbodies, and multivesicular bodies predominates. Vacuoles are abundant in the posterior. Ribosomes occur throughout the cytoplasm. The flagellar apparatus consists of the following: a short fibrillar rhizoplast connecting both kinetosome and nonfunctional centriole to an electron-opaque bar on the nuclear envelope; an elongated transition zone; and a 9 + 2 flagellum axoneme running much of the length of the zoospore through to the posterior end. Props do not connect the kinetosome to the plasmalemma; however, prop parts connect to the kinetosome, and prop parts connect to the plasmalemma at the posterior end of the zoospore. The taxonomic relationship to other chytrids is discussed; the zoospore is similar to that of O. brassicae (Woronin) Dang, and Rhizophlyctis rosea (deBary &Woronin) Fischer, and somewhat similar to that of Rozella allomycis Foust.

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.

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