Ultrastructure de l'hyphe végétatif de Sclerotinia fructigena

1979 ◽  
Vol 57 (12) ◽  
pp. 1299-1313 ◽  
Author(s):  
L. Najim ◽  
G. Turian
Keyword(s):  
Endoplasmic Reticulum ◽  
Apicobasal Polarity ◽  
Apical Vesicles ◽  
Hyphal Tip

Vegetative hyphae of Sclerotinia (Monilia) fructigena (Ader and Ruhl) show a sharply polarized distribution of their organelles. In their tip, the "Spitzenkörper" made up of a microvesicular aggregate is well delimitated and surrounded by apical vesicles which can fuse with the plasmalemma. Excluded from the hyphal tip, mitochondria are elongated in the apicobasal polarity and in contact with numerous and often voluminous lipid globules. It appears that these lipid globules originate from the endomembranous system of the hyphae. The endoplasmic reticulum extends into pseudogolgi cisternae apparently generating apical vesicles. In the new hyphal branches, polarity seems to be initiated by the newly oriented endoplasmic reticulum from which originate microvesicles later aggregating into the new "Spitzenkörper." An elaborate system of microtubules also seems implicated in the further maintenance of the polarity of the growing hyphae. Microbodies with pseudocrystalline inclusions are also oriented according to the developmental polarity.

scholarly journals RADIOAUTOGRAPHIC VISUALIZATION OF THE INCORPORATION OF GALACTOSE-3H AND MANNOSE-3H BY RAT THYROIDS IN VITRO IN RELATION TO THE STAGES OF THYROGLOBULIN SYNTHESIS

1969 ◽  
Vol 43 (2) ◽  
pp. 289-311 ◽  
Author(s):  
P. Whur ◽  
Annette Herscovics ◽  
C. P. Leblond
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Light Microscope ◽  
Detectable Effect ◽  
Apical Vesicles ◽  
Rat Thyroid

Rat thyroid lobes incubated with mannose-3H, galactose-3H, or leucine-3H, were studied by radioautography. With leucine-3H and mannose-3H, the grain reaction observed in the light microscope is distributed diffusely over the cells at 5 min, with no reaction over the colloid. Later, the grains are concentrated towards the apex, and colloid reactions begin to appear by 2 hr. With galactose-3H, the reaction at 5 min is again restricted to the cells but it consists of clumped grains next to the nucleus. Soon after, grains are concentrated at the cell apex and colloid reactions appear in some follicles as early as 30 min. Puromycin almost totally inhibits incorporation of leucine-3H and mannose-3H, but has no detectable effect on galactose-3H incorporation during the 1st hr. Quantitation of electron microscope radioautographs shows that mannose-3H label localizes initially in the rough endoplasmic reticulum, and by 1–2 hr much of this reaction is transferred to the Golgi apparatus. At 3 hr and subsequently, significant reactions are present over apical vesicles and colloid, while the Golgi reaction declines. Label associated with galactose-3H localizes initially in the Golgi apparatus and rapidly transfers to the apical vesicles, and then to the colloid. These findings indicate that mannose incorporation into thyroglobulin precursors occurs within the rough endoplasmic reticulum; these precursors then migrate to the Golgi apparatus, where galactose incorporation takes place. The glycoprotein thus formed migrates via the apical vesicles to the colloid.

scholarly journals Structure and Distribution of Organelles and Cellular Location of Calcium Transporters in Neurospora crassa

2009 ◽  
Vol 8 (12) ◽  
pp. 1845-1855 ◽  
Author(s):  
Barry J. Bowman ◽  
Marija Draskovic ◽  
Michael Freitag ◽  
Emma Jean Bowman
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Neurospora Crassa ◽  
Fluorescent Protein ◽  
Protein A ◽  
Vacuolar Membrane ◽  
Red Fluorescent Protein ◽  
Animal Cells ◽  
Marker Proteins ◽  
Hyphal Tip

ABSTRACT We wanted to examine the cellular locations of four Neurospora crassa proteins that transport calcium. However, the structure and distribution of organelles in live hyphae of N. crassa have not been comprehensively described. Therefore, we made recombinant genes that generate translational fusions of putative organellar marker proteins with green or red fluorescent protein. We observed putative endoplasmic reticulum proteins, encoded by grp-78 and dpm, in the nuclear envelope and associated membranes. Proteins of the vacuolar membrane, encoded by vam-3 and vma-1, were in an interconnected network of small tubules and vesicles near the hyphal tip, while in more distal regions they were in large and small spherical vacuoles. Mitochondria, visualized with tagged ARG-4, were abundant in all regions of the hyphae. Similarly, we tagged the four N. crassa proteins that transport calcium with green or red fluorescent protein to examine their cellular locations. NCA-1 protein, a homolog of the SERCA-type Ca2+-ATPase of animal cells, colocalized with the endoplasmic reticulum markers. The NCA-2 and NCA-3 proteins are homologs of Ca2+-ATPases in the vacuolar membrane in yeast or in the plasma membrane in animal cells. They colocalized with markers in the vacuolar membrane, and they also occurred in the plasma membrane in regions of the hyphae more than 1 mm from the tip. The cax gene encodes a Ca2+/H+ exchange protein found in vacuoles. As expected, the CAX protein localized to the vacuolar compartment. We observed, approximately 50 to 100 μm from the tip, a few spherical organelles that had high amounts of tagged CAX protein and tagged subunits of the vacuolar ATPase (VMA-1 and VMA-5). We suggest that this organelle, not described previously in N. crassa, may have a role in sequestering calcium.

The ultrastructure of sexual reproduction in Pythium acanthicum

1976 ◽  
Vol 54 (19) ◽  
pp. 2193-2203 ◽  
Author(s):  
R. H. Haskins ◽  
J. A. Brushaber ◽  
J. J. Child ◽  
L. B. Holtby
Keyword(s):  
Endoplasmic Reticulum ◽  
Sexual Reproduction ◽  
Contact Zone ◽  
Periplasmic Space ◽  
Spine Development ◽  
Storage Body ◽  
Cytoplasmic Ribosomes ◽  
Pythium Acanthicum ◽  
Hyphal Tip

The young oogonium and young antheridium in Pythium acanthicum Drechsler are densely and randomly packed with numerous mitochondria, dictyosomes, nuclei, interlocking vacuoles of several types, some of which contain a dense storage body, a variety of vesicles, endoplasmic reticulum, and cytoplasmic ribosomes. Wall vesicles, evenly distributed next to the plasma-lemma in rapidly growing oogonia, become localized in groups at points where they appear to initiate the hyphal tip-like development of the oogonial spines. They are also found on both sides of the antheridium−oogonium contact zone. Spine development starts shortly after antheridium−oogonial contact is made and ceases with entry of antheridial material into the oogonium. Excess nuclei, mitochondria, and various organelles are abandoned in the periplasmic space, where they normally quickly disintegrate when the oospore is formed. The periplasmic space is invaded frequently by vegetative hyphae originating outside of the oogonium.

Ultrastructure of the Genital Duct Epithelium of the Male Port Jackson Shark, Heterodontus-Portusjacksoni

1992 ◽  
Vol 40 (3) ◽  
pp. 257 ◽  
Author(s):  
RC Jones ◽  
M Lin
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Close Association ◽  
Ciliated Cells ◽  
Dense Bodies ◽  
Ductuli Efferentes ◽  
Apical Vesicles

The genital ducts of Heterodontus portusjacksoni are lined by a ciliated epithelium. In the ductuli efferentes the epithelium is low and contains numerous intraepithelial leucocytes which often contain large dense bodies. All epithelial cells are ciliated and are characterised by apical vesicles, vacuoles and glycogen granules, some rough endoplasmic reticulum, dense bodies and lipid droplets, and a Golgi apparatus. The initial segment of the ductus epididymidis is lined by a very tall epithelium of ciliated and non-ciliated cells. The non-ciliated cells contain numerous apical vesicles, a large Golgi apparatus and numerous mitochondria and secretory granules in close association with an extensive endoplasmic reticulum. The terminal segment of the ductus epididymidis is lined by a low columnar epithelium. A proximal region, occupying part of the head of the epididymis, is similar to the epithelium in the ductuli efferentes. Distally, all the epithelial cells are ciliated. They are characterised by considerable dilated endoplasmic reticulum, a Golgi apparatus, apical vesicles, and numerous mitochondria and secretory granules. The secretory tubules of Leydig's glands are lined by a very tall epithelium with non-ciliated cells containing extensive, dilated, rough endoplasmic reticulum, a large Golgi apparatus, and numerous mitochondria and secretory granules. The significance of the structural differentiation of the duct is discussed in relation to the evolution of the mammalian epididymis.

scholarly journals Localization of thyroglobulin antigenicity in rat thyroid sections using antibodies labled with peroxidase or (125)I-radioiodine

1977 ◽  
Vol 74 (3) ◽  
pp. 992-1015 ◽  
Author(s):  
J Paiement ◽  
CP Leblond
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Follicular Cells ◽  
Lysosomal Degradation ◽  
High Concentration ◽  
Different Types ◽  
Apical Vesicles ◽  
Rat Thyroid ◽  
Silver Grains ◽  
Distinct Distribution

In the hope of localizing thyroglobulin within focullar cells of the thyroid gland, antibodies raised against rat thyroglobulin were labeled with the enzyme horseradish peroxidase or with (125)I-radioiodine. Sections of rat thyroids fixed in glutaraldehyde and embedded in glycol methacrylate or Araldite were placed in contact with the labeled antibodies. The sites of antibody binding were detected by diaminobenzidine staining in the case of peroxidase labeling, and radioautography in the case of 125(I) labeling. Peroxidase labeling revealed that the antibodies were bound by the luminal colloid of the thyroid follicles and, within focullar cells, by colloid droplets, condensing vacuoles, and apical vesicles. (125)I labeling confirmed these findings, and revealed some binding of antibodies within Golgi saccules and rough endoplasmic reticulum. This method provides a visually less distinct distribution than peroxidase labeling, but it allowed ready quantitation of the reactions by counts of silver grains in the radioautographs. The counts revealed that the concentration of label was similar in the luminal colloid of different follicles, but that it varied within the compartments of follicular cells. A moderate concentration was detected in rough endoplasmic reticulum and Golgi saccules, whereas a high concentration was found in condensing vacuoles, apical vesicles, and in the luminal colloid. Varying amounts of label were observed over the different types of colloid droplets, and this was attributed to various degrees of lysosomal degradation of thyroglobulin. It is concluded that the concentration of thyroglobulin antigenicity increases during transport from the ribosomal site of synthesis to the follicular colloid, and then decreases during the digestion of colloid droplets which leads to the release of the thyoid hormone.

scholarly journals IN VIVO INCORPORATION OF 3H-GALACTOSE BY THYROID FOLLICULAR CELLS OF THE RAT, AS SHOWN BY ELECTRON MICROSCOPIC RADIOAUTOGRAPHY

1972 ◽  
Vol 20 (3) ◽  
pp. 220-224 ◽  
Author(s):  
A. HADDAD
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Side Chains ◽  
Follicular Cells ◽  
Electron Microscopic ◽  
Thyroid Follicular Cells ◽  
Apical Vesicles ◽  
Electron Microscopic Radioautography

Radioactive galactose was injected intravenously into rats and localized in thyroid follicular cells by electron microscopic radioautography at intervals ranging from 2.5 to 30 min after injection. The galactose label was mostly present in the Golgi apparatus at 2.5 min, with some of it in the adjacent rough endoplasmic reticulum. By 30 min, the label was found in apical vesicles and colloid. It was concluded that galactose is added to the carbohydrate side chains of incomplete thyroglobulin molecules during their travel through the cisternae of the endoplasmic reticulum into the Golgi apparatus; the uptake begins as this organelle is approached, but predominates within it. The thyroglobulin molecule which has thus been labeled is transported by the apical vesicles to the colloid.

Hyphal tip growth in Achlya. I. Cytoplasmic organization

1980 ◽  
Vol 26 (9) ◽  
pp. 1132-1140 ◽  
Author(s):  
T. W. Hill ◽  
J. T. Mullins
Keyword(s):  
Electron Microscopy ◽  
Fibrous Material ◽  
Tip Growth ◽  
Phosphotungstic Acid ◽  
Chromic Acid ◽  
Periodic Acid ◽  
Cytoplasmic Vesicles ◽  
Cytoplasmic Organization ◽  
Apical Vesicles ◽  
Hyphal Tip

Growing apices of Achlya ambisexttalis Raper hyphae were examined by electron microscopy using cytochemical techniques. Apical vesicles can be grouped into two major classes based upon size and cytochemical reactions. Vesicles of the most prominent class are about 150 nm in diameter and possess contents which appear fibrous in thin section. This fibrous material reacts positively with the periodic acid – silver methenamine (PASM) cytochemical test for polysaccharides. Most of these same vesicles also display IDPase activity, and a smaller number display acid phosphatase activity. Vesicles of the second class are about 80 nm in diameter, and include coated vesicles and others which react positively for IDPase activity. They show a negative PASM reaction in contrast with the larger vesicles. Some of these smaller vesicles are stained by the phosphotungstic acid – chromic acid (PTA–CrO3) stain, whereas 150-nm vesicles are not. The source of at least some vesicles of both major classes appears to be the Golgi apparatus. It is proposed that the IDPase activity and carbohydrate content of the 150-nm cytoplasmic vesicles could serve as useful markers in their isolation.

The ultrastructure of Endothia parasitica. Comparison of a virulent with a hypovirulent isolate

1983 ◽  
Vol 61 (2) ◽  
pp. 389-399 ◽  
Author(s):  
Joseph R. Newhouse ◽  
Harvey C. Hoch ◽  
William L. MacDonald
Keyword(s):  
Endoplasmic Reticulum ◽  
Freeze Substitution ◽  
Subcellular Structure ◽  
Apical Vesicles ◽  
Viruslike Particles ◽  
Endothia Parasitica ◽  
Tip Cells ◽  
Hyphal Wall ◽  
Hyphal Apex ◽  
Membranous Material

Hyphae of virulent (v) Endothia parasitica isolate 16-15-1 (West Virginia) and hypovirulent (hv) isolate Ep-4 (France) were preserved by freeze-substitution, embedded, and longitudinally sectioned to describe and compare their subcellular structure. General ultrastructural features of both were similar. Apical vesicles and uncoated microvesicles were common constituents of the extreme hyphal apex. Abundant membranous material also was seen in this region in some tip sections of hv isolate Ep-4. Filasomes were located along the lateral hyphal wall just behind the apex, and one was observed to be fused with the plasmalemma. Golgi cisternae were numerous in the tip area and appeared very flat and fenestrated, and often were closely associated with mitochondria. Components of the vacuole system were variously shaped, totally electron dense in young hyphae, and lighter with discernible inclusions in older hyphae. Spherical, membrane-bounded viruslike particles (VLPs), 51–78 nm in diameter, were observed in tip cells of hv isolate Ep-4, but not v isolate 16-15-1. The VLPs may be responsible for hypovirulence in the Ep-4 isolate. Endoplasmic reticulum cisternae contact in hyphae of Ep-4 may have been related to the presence of VLPs.

In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

1974 ◽  
Vol 32 ◽  
pp. 132-133
Author(s):  
John J. Wolosewick ◽  
John H. D. Bryan
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Nuclear Ring ◽  
Rough Er ◽  
Distal Direction ◽  
In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

Ultrastructure of the Parotid Gland of the Nine-Banded Armadillo

1977 ◽  
Vol 35 ◽  
pp. 640-641
Author(s):  
J. R. Ruby
Keyword(s):  
Endoplasmic Reticulum ◽  
Parotid Gland ◽  
Periodic Acid ◽  
Acinar Cells ◽  
Duct System ◽  
Parotid Glands ◽  
Dasypus Novemcinctus ◽  
Anterior Portion ◽  
Periodic Acid Schiff ◽  
Thin Sections

Parotid glands were obtained from five adult (four male and one female) armadillos (Dasypus novemcinctus) which were perfusion-fixed. The glands were located in a position similar to that of most mammals. They extended interiorly to the anterior portion of the submandibular gland.In the light microscope, it was noted that the acini were relatively small and stained strongly positive with the periodic acid-Schiff (PAS) and alcian blue techniques, confirming the earlier results of Shackleford (1). Based on these qualities and other structural criteria, these cells have been classified as seromucous (2). The duct system was well developed. There were numerous intercalated ducts and intralobular striated ducts. The striated duct cells contained large amounts of PAS-positive substance.Thin sections revealed that the acinar cells were pyramidal in shape and contained a basally placed, slightly flattened nucleus (Fig. 1). The rough endoplasmic reticulum was also at the base of the cell.

Sign in / Sign up

Export Citation Format

Share Document