Variation in ultrastructure of mucoid coat and shell membrane secretion of a dasyurid marsupial

1996 ◽  
Vol 8 (4) ◽  
pp. 645 ◽  
Author(s):  
CT Roberts ◽  
WG Breed
Keyword(s):  
Electron Density ◽  
Polyclonal Antibodies ◽  
Secretory Granules ◽  
Granular Structure ◽  
Sminthopsis Crassicaudata ◽  
Shell Membrane ◽  
Early Embryos ◽  
Immunogold Cytochemistry ◽  
Ultrastructural Appearance ◽  
Electron Lucent

In the dasyurid marsupial Sminthopsis crassicaudata, the shell membrane of cleaving embryos has a compact granular structure but becomes fibrous around blastocysts. Polyclonal antibodies were raised against the extracellular coats, mucoid and shell membrane, of oocytes and early embryos. Immunogold cytochemistry resulted in labelling of secretory granules in the epithelia of both the ampulla and isthmus of the oviduct, although the secretory granules of these two regions differed in their ultrastructural appearance. Those in the ampulla were heterogeneous with areas of varying electron density, whereas those in the isthmus were electron dense and homogeneous. Shell membrane precursors were found in secretory granules in the epithelia of the uterotubal junction and endometrial glands and were electron lucent.

XMAP230 is required for the assembly and organization of acetylated microtubules and spindles in Xenopus oocytes and eggs

1998 ◽  
Vol 111 (16) ◽  
pp. 2315-2327 ◽  
Author(s):  
B.J. Cha ◽  
B. Error ◽  
D.L. Gard
Keyword(s):  
Late Stage ◽  
Xenopus Oocytes ◽  
Early Stage ◽  
Polyclonal Antibodies ◽  
Stage Iv ◽  
Stage I ◽  
Meiotic Spindle ◽  
Heat Stable ◽  
Early Embryos ◽  
And Function

We used affinity-purified polyclonal antibodies to characterize the distribution and function of XMAP230, a heat-stable microtubule-associated protein isolated from Xenopus eggs, during oogenesis. Immunoblots revealed that XMAP230 was present throughout oogenesis and early development, but was most abundant in late stage oocytes, eggs, and early embryos. Immunofluorescence microscopy revealed that XMAP230 was associated with microtubules in oogonia, post-mitotic stage 0 oocytes, early stage I oocytes, and during stage IV-VI of oogenesis. However, staining of microtubules by anti-XMAP230 was not detectable during late stage I through stage III. In stage VI oocytes, anti-XMAP230 stained a large subset of microtubules that were also stained with monoclonal antibodies specific for acetylated (α)-tubulin. During oocyte maturation, XMAP230 was associated with the transient microtubule array that serves as the precursor of the first meiotic spindle, as well as both first and second meiotic spindles. The extensive array of cytoplasmic microtubules present throughout maturation was not detectably stained by anti-XMAP230. Microinjection of anti-XMAP230 locally disrupted the organization and acetylation of microtubules in stage VI oocytes, and reduced the re-acetylation of microtubules during recovery from cold-induced microtubule disassembly. Subsequent maturation of oocytes injected with anti-XMAP230 resulted in defects in the assembly of the transient microtubules array and first meiotic spindle. These observations suggest that XMAP230 is required for the stabilization and organization of cytoplasmic and spindle microtubules in Xenopus oocytes and eggs.

Variability in mitochondria of zebrafish photoreceptor ellipsoids

2014 ◽  
Vol 31 (1) ◽  
pp. 11-23 ◽  
Author(s):  
R. TARBOUSH ◽  
I. NOVALES FLAMARIQUE ◽  
G.B. CHAPMAN ◽  
V.P. CONNAUGHTON
Keyword(s):  
Electron Density ◽  
Light Filter ◽  
Adult Fish ◽  
Adult Zebrafish ◽  
Ultrastructural Examination ◽  
Internal Morphology ◽  
Different Types ◽  
Absorbance Peak ◽  
And Function ◽  
Electron Lucent

AbstractUltrastructural examination of photoreceptor inner segment ellipsoids in larval (4, 8, and 15 days postfertilization; dpf) and adult zebrafish identified morphologically different types of mitochondria. All photoreceptors had mitochondria of different sizes (large and small). At 4 dpf, rods had small, moderately stained electron-dense mitochondria (E-DM), and two cone types could be distinguished: (1) those with electron-lucent mitochondria (E-LM) and (2) those with mitochondria of moderate electron density. These distinctions were also apparent at later ages (8 and 15 dpf). Rods from adult fish had fewer mitochondria than their corresponding cones. The ellipsoids of some fully differentiated single and double cones contained large E-DM with few cristae; these were surrounded by small E-LM with typical internal morphology. The mitochondria within the ellipsoids of other single cones showed similar electron density. Microspectrophotometry of cone ellipsoids from adult fish indicated that the large E-DM had a small absorbance peak (∼0.03 OD units) and did not contain cytochrome-c, but crocetin, a carotenoid found in old world monkeys. Crocetin functions to prevent oxidative damage to photoreceptors, suggesting that the ellipsoid mitochondria in adult zebrafish cones protect against apoptosis and function metabolically, rather than as a light filter.

An Ultrastructural Study of Adenocarcinoma of the Small Intestine in Sheep

1985 ◽  
Vol 22 (6) ◽  
pp. 552-560 ◽  
Author(s):  
A. D. Ross ◽  
W. A. Day
Keyword(s):  
Tumor Cells ◽  
Secretory Granules ◽  
Tubular Adenocarcinoma ◽  
Hexagonal Symmetry ◽  
Basal Nuclei ◽  
Differentiated Cells ◽  
Ultrastructural Appearance ◽  
Intracytoplasmic Lumina ◽  
Small Intestinal ◽  
Metastatic Sites

The ultrastructural appearance at primary and metastatic sites of ten ovine small intestinal adenocarcinomas was that of scirrhous tubular adenocarcinoma. Polygonal undifferentiated tumor cells had desmosomes, folded nuclei, and moderate numbers of mitochondria but few other organelles. More differentiated cells were columnar with apical microvilli and basal nuclei. They contained granular endoplasmic reticulum, Golgi and secretory granules. Microvillus-lined intracytoplasmic lumina (5–10 μm diameter), fibrous filaments (10 nm diameter, up to 1.4 μm length) and tubular paracrystalline arrays (hexagonal symmetry, 37-nm periodicity) in lumina and secretory granules were seen in some tumor cells in all ten sheep.

Regulatory subunits of cyclic AMP-dependent protein kinase: presence in granules and secretion by exocrine and endocrine cells

1989 ◽  
Vol 93 (4) ◽  
pp. 675-681
Author(s):  
A.R. Hand ◽  
M.I. Mednieks
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Endocrine Cells ◽  
Polyclonal Antibodies ◽  
Secretory Granules ◽  
Regulatory Subunit ◽  
Secretory Cells ◽  
Dependent Protein Kinase ◽  
Regulatory Subunits ◽  
Dependent Protein

Cyclic AMP-dependent protein kinase (cAPK) is the intracellular mediator of signal transduction events involving the adenylate cyclase-cyclic AMP system. A monoclonal antibody (MAb BB1) to the type II regulatory subunit (RII) of cAPK was used in a post-embedding immunogold-labeling procedure to determine the ultrastructural localization of RII in several different secretory cells of the rat. Label was present in nuclei, especially over the heterochromatin, and in the cytoplasm, particularly in areas containing rough endoplasmic reticulum. Immunolabeled RII was also present in secretory granules of the parotid gland, exocrine and endocrine pancreas, seminal vesicle, anterior and intermediate pituitary, and intestinal endocrine cells. Photoaffinity labeling of parotid saliva, pancreatic and seminal fluids with the cyclic AMP analogue, 32P-labeled-8-azido-cyclic AMP, revealed the presence of cyclic AMP-binding proteins with electrophoretic mobilities similar to those of authentic cAPK regulatory subunits. These results confirm our previous observations on the localization of cAPK regulatory subunits in the rat parotid using polyclonal antibodies, and extend them to a number of other exocrine and endocrine cells. The apparent widespread occurrence of cAPK subunits in secretory granules and secretory fluids suggests that cAPK may be involved in specific intragranular regulatory and/or phosphorylation events, or that it has an unidentified extracellular function.

scholarly journals Intracellular sites of proteolytic processing of pro-opiomelanocortin in melanotrophs and corticotrophs in rat pituitary.

1991 ◽  
Vol 39 (6) ◽  
pp. 809-821 ◽  
Author(s):  
S Tanaka ◽  
M Nomizu ◽  
K Kurosumi
Keyword(s):  
Polyclonal Antibody ◽  
Secretory Granules ◽  
Protein A ◽  
Proteolytic Processing ◽  
Pars Intermedia ◽  
Gold Particles ◽  
Melanocyte Stimulating Hormone ◽  
Rat Pituitary ◽  
Almost All ◽  
Electron Lucent

A synthetic peptide (ST-1) corresponding to the cleavage site between ACTH and beta-lipotropic hormone moieties of murine pro-opiomelanocortin (POMC) was constructed and its polyclonal antibody was generated. This antiserum immunoprecipitated only POMC from extracts of AtT-20 cells. Moreover, an antiserum raised against porcine ACTH immunoprecipitated both ACTH[1-39] and POMC. When ultra-thin frozen sections of melanotrophs in rat pars intermedia were immunolabeled with anti-ST-1 followed by protein A-gold, gold particles indicating the presence of POMC were selectively found in the electron-dense secretory granules in the Golgi area. In addition, the immunolabeling was also observed in the cisternae of the Golgi apparatus and rough endoplasmic reticulum. In contrast, with a polyclonal antibody specific for alpha-melanocyte-stimulating hormone the gold particles were found exclusively in the electron-lucent secretory granules, with none seen in the electron-dense secretory granules. With anti-ACTH serum, gold particles were observed in the electron-dense and -lucent secretory granules. In corticotrophs in the pars distalis, many gold particles indicating the presence of POMC were observed in the Golgi and peripheral secretory granules, but the percentage of immunolabeling in the peripheral secretory granules varied from cell to cell. On the other hand, ACTH immunolabeling was found in almost all the secretory granules. This finding suggests that the processing of POMC in corticotrophs might occur in the relatively peripheral granules. These results suggest that the intracellular sites of POMC processing are somewhat different between melanotrophs and corticotrophs in the pituitary.

Development of the alimentary tract during morphogenesis of the metacercariae of Levinseniella brachysoma

1993 ◽  
Vol 67 (2) ◽  
pp. 87-94 ◽  
Author(s):  
K. V. Galaktionov ◽  
I.I. Malkova
Keyword(s):  
Electron Density ◽  
Post Infection ◽  
Plasma Membranes ◽  
Alimentary Tract ◽  
Secretory Granules ◽  
Embryonic Cells ◽  
Apical Cytoplasm ◽  
First Time

AbstractFor the first time the development of the alimentary tract of Levinseniella brachysoma metacercaria (Trematoda: Microphallidae) obtained experimentally from Gammarus oceanicus has been described. The foregut primordium in 16-day-old metacercariae is represented by a syncytial cylindrical cord, resulting from the fusion of embryonic cells. Non-fused parts of the plasma membranes of adjacent cells are revealed as gap cavities within the cord. Later (30th day post infection) the lumen of the foregut is formed as a result of both partial vacuolization of the cytoplasm and by a broadening of the gap cavities, resulting from a thinning of the cytoplasmic spaces between them. Besides the usual organelles, the foregut of the mature metacercaria (42nd day p.i.) contains dense secretory granules in the apical cytoplasm region and numerous microtubules in basal areas. The cellular gastrodermis is formed later than the foregut syncytium (on day 30 p.i.); its large cells contain well-developed Golgi complexes, RER and mitochondria. A noteable inclusion of the gastrodermal cells of mature metacercariae are spherical granules of moderate electron density measuring up to 3 μm in diameter. On the basis of an analysis of the ultrastructural data the possible functioning of the metacercarial alimentary tract is discussed.

scholarly journals Cytochemical characterization of sulfo- and sialoglycoconjugates of human laryngeal glandular cells.

1994 ◽  
Vol 42 (4) ◽  
pp. 485-496 ◽  
Author(s):  
M T Castells ◽  
J F Madrid ◽  
M Avilés ◽  
J A Martínez-Menárguez ◽  
J Ballesta
Keyword(s):  
Colloidal Gold ◽  
Secretory Granules ◽  
Morphological Variability ◽  
Electron Microscopic ◽  
Glandular Cells ◽  
Electron Lucent

The composition and distribution of sulfo- and sialoglycoconjugates in human laryngeal glands have been investigated at light and electron microscopic levels by use of peroxidase-, digoxigenin-, and colloidal gold-conjugated lectins in combination with several chemical and enzymatic deglycosylation procedures. The present study reveals a variety of terminal oligosaccharide sequences in serous and mucous glands. Serous cells contained glycoconjugates with terminal Neu5Ac (alpha 2-3) Gal (beta 1-4) GlcNAc, Neu5Ac (alpha 2-6) Gal/GalNAc, Neu5Ac (alpha 2-3/6) Gal (beta 1-3 GalNAc, GlcNAc, and Gal (beta 1-4) GlcNAc sequences. Scarce SO4Gal(beta 1-3)GalNAc terminal oligosaccharide chans were detected. Serous cells show wide morphological variability of secretory granules (electron lucent, electron dense, and bizonal) with different lectin affinities. Glycoconjugates in human laryngeal mucous glands contained a variety of terminal oligosaccharide sequences including SO4Gal(beta 1-4)GlcNAc, SO4Gal(beta 1-3) GalNAc, SO4GalNAc, and Neu5Ac(alpha 2-3)GalNAc.

Modifications of pars intermedia cells of ovariectomized rats by oestrogen and progesterone

1986 ◽  
Vol 111 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Adriana Beatriz Ferreira ◽  
Maria Ester Celis
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Secretory Activity ◽  
Ovariectomized Rats ◽  
Ultrastructural Changes ◽  
Synthetic Activity ◽  
Pars Intermedia ◽  
Cytological Features ◽  
Electron Lucent

Abstract. The effects of the ovarian steroids, oestradiol benzoate (EB), and progesterone (P) on the cells of pars intermedia (PI) from chronically ovariectomized rats (CHR-OVX) were analyzed by qualitative and quantitative electron microscopy (EM) at different intervals after steroid injection. The PI cells of CHR-OVX are rich in secretory granules but poor in organelles related to hormonal synthesis. Twenty-four h after EB administration the cells exhibited cytological features indicative of an increased synthetic activity. These included hypertrophy of rough endoplasmic reticulum, cisternae, a moderately developed Golgi complex, and newly formed granules. These features were also observed in PI cells 48 h after EB administration. Thirty-two and 56 h after the treatment, the PI cells showed signs of both increased synthetic and secretory activity. Thus, it was possible to observe a well-developed rough endoplasmic reticulum, and Golgi apparatus, numerous electron-lucent vesicles, and secretory granules in contact with the cell membrane. However, no exocytotic figures were observed. Progesterone administration resulted in considerable modifications of the ultrastructural features of PI cells also indicative of increased synthetic and secretory activity. The greatest modifications were observed in the mornings with changes that were 12 h out of phase with respect to those observed with EB. Quantitative estimations of the variation in the content of secretory granules of PI cells fully confirmed the qualitative observations described above. The serum α-MSH concentrations in ovariectomized rats was found to be incresed 24 h after administration of a single dose of EB and thereafter serum MSH exhibited high levels in the afternoon, whereas the values in the morming were lower. In spayed rats, progesterone injection also resulted in an increase of the serum MSH concentration, but with high levels in the mornings and low levels in the afternoons. In conclusion, EB and P induce modifications in the levels of α-MSH as well as in the ultrastructural changes of the PI cells.

scholarly journals THE ERGASTOPLASM

1953 ◽  
Vol 98 (6) ◽  
pp. 607-618 ◽  
Author(s):  
Jules M. Weiss
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Secretory Granules ◽  
Granular Structure ◽  
Ground Substance ◽  
Mitochondrial Membranes ◽  
Cytoplasmic Matrix ◽  
Pancreatic Exocrine ◽  
Exocrine Cell ◽  
Membranous Wall

The fine structure of the ergastoplasm of the pancreatic exocrine cell of Swiss albino mice has been studied with the electron microscope. It was found that this material consists of sac-like structures, which may be called ergastoplasmic sacs, embedded in an amorphous granular ground substance, the cytoplasmic matrix. The membranous wall of the ergastoplasmic sac is a structure approximately 250 A wide. Except for its greater electron density and granular structure, the ergastoplasmic membrane is similar in appearance to the nuclear, plasma, and mitochondrial membranes. From data available in the literature, and from our own evidence, the conclusion can be drawn that the ergastoplasmic membrane contains ribonucleic acid. The mode of formation of the ergastoplasm and secretory granules was studied in animals which were first fasted and subsequently fed. It was found that ergastoplasm is formed within the cytoplasm, near the nuclear membrane, and possibly from the plasma membrane. The secretory granules were observed to arise by accumulation of materials within small ergastoplasmic sacs.

Fine Structure of the Ultimobranchial Gland in the Chick

1971 ◽  
Vol 29 ◽  
pp. 510-511
Author(s):  
A. S. Chan
Keyword(s):  
Fine Structure ◽  
Epithelial Cells ◽  
Cell Membrane ◽  
Electron Density ◽  
Osmium Tetroxide ◽  
Secretory Granules ◽  
Parenchymal Cell ◽  
Cell Types ◽  
Dark Cells ◽  
Ultimobranchial Gland

Although the ultimobranchial gland of the chick has been shown to contain large amounts of calcitonin relatively few reports have been published on its fine structure. In the present study, the ultrastructure of the chick ultimobranchial gland, with emphasis on the cells which appear to be the producers of the hormone, will be examined. Ultimobranchial glands were obtained from twenty 2-week-old chicks and fixed in glutaraldehyde followed by osmium tetroxide.The gland is composed of aggregate of cords and clusters of cells interspersed with variable numbers of cyst-like cavities. Two parenchymal cell types, namely, light and dark cells can be recognized (Figs. 1,2,3). Epithelial cells, varying from columnar to cuboidal, line the cavities of the cysts.Light cells form the majority of the cell types (Fig. 1). The cytoplasm is characterized by the presence of membrane-limited secretory granules, measuring from 100 to 350 mμ in diameter. The contents of the secretory granules vary in electron density from moderate to extreme (Figs. 1,2). Secretory granules are distributed randomly in the cytoplasm although some are lined near the cell membrane.

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