Changes of organelles associated with the differentiation of epidermal melanocytes in the mouse

Development ◽  
1978 ◽  
Vol 43 (1) ◽  
pp. 107-121
Author(s):  
Tomohisa Hirobe ◽  
Takuji Takeuchi
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Mouse Skin ◽  
Newborn Mouse ◽  
Electron Microscopic ◽  
Induced Differentiation ◽  
Newborn Mice ◽  
Old Mice

Electron microscopic observations on normally differentiating and α-MSH (melanocytestimulating hormone)-treated epidermal melanocytes of newborn mouse skin were carried out. The process of melanocyte differentiation from premelanosome-containing melanoblasts was investigated in detail with respect to melanosomes as markers. Melanoblasts containing unmelanized premelanosomes gradually decreased in number after birth, while the number of melanocytes rapidly increased. The epidermis of α-MSH-treated 3-day-old mice and normal 6-day-old mice contained melanocytes with numerous fully melanized melanosomes, and with no or only a few melanoblasts. Changes in other organelles in differentiating melanocytes were also noticeable. Golgi apparatus and RER (rough endoplasmic reticulum) decreased in number during the normal or α-MSH-induced differentiation of the epidermal melanocytes, though the number of mitochondria showed no notable change. The number of SER (smooth endoplasmic reticulum) per cell did not change in the cells of newborn mice, while in α-MSH-treated cells the number increased significantly. These results led us to an assumption that Golgi apparatus or RER transforms into other forms of organelles including melanosomes and SER during the differentiation of melanocytes.

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.

Redistribution of material labelled with [3H]mannose in amoebae induced to undergo pinocytosis

1982 ◽  
Vol 58 (1) ◽  
pp. 79-93
Author(s):  
C.J. Flickinger
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Cell Surface ◽  
Rough Endoplasmic Reticulum ◽  
Lysosomal Enzymes ◽  
Surface Material ◽  
Albumin Solution ◽  
Electron Microscopic ◽  
Normal Medium ◽  
Electron Microscopic Radioautography

The synthesis, transport, and disposition of material labelled with [3H]mannose were studied by electron microscopic radioautography in normal amoebae and in cells that had internalized cell surface as a result of being induced to undergo pinocytosis. Control amoebae were injected with the precursor and placed in normal medium. The Golgi apparatus and rough endoplasmic reticulum were heavily labelled at the earliest intervals, while radioactivity of the cell surface peaked 12 h after injection of precursor. The experimental cells were injected, placed in bovine serum albumin solution from 15 to 60 min after injection, and then removed to normal medium until fixation. Incorporation of the precursor into the rough endoplasmic reticulum was near normal, but the proportions of grains associated with the Golgi apparatus and the cell surface were greatly reduced. The percentage of grains overlying vacuoles increased 12 h after injection, notably in the case of polymorphous vacuoles and dense vacuoles, both of which were identified as lysosomes with the acid phosphatase reaction. The results suggest that addition to the surface of components labelled with [3H]mannose was diminished following induction of pinocytosis. Incorporation of the precursor appeared to be shifted from cell surface material to lysosomal contents, possibly lysosomal enzymes. It is thought that this shift occurred in response to the need for the cell to digest unusually large amounts of endocytosed protein. Recycling of cell surface under these conditions is considered possible.

scholarly journals LYSOSOMES AND GERL IN NORMAL AND CHROMATOLYTIC NEURONS OF THE RAT GANGLION NODOSUM

1967 ◽  
Vol 33 (2) ◽  
pp. 419-435 ◽  
Author(s):  
Eric Holtzman ◽  
Alex B. Novikoff ◽  
Humberto Villaverde
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Smooth Endoplasmic Reticulum ◽  
Cell Periphery ◽  
Electron Microscopic ◽  
Ganglion Nodosum ◽  
Autophagic Vacuoles ◽  
Inosine Diphosphatase ◽  
Nissl Substance ◽  
Membranous Material

The rat ganglion nodosum was used to study chromatolysis following axon section. After fixation by aldehyde perfusion, frozen sections were incubated for enzyme activities used as markers for cytoplasmic organelles as follows: acid phosphatase for lysosomes and GERL (a Golgi-related region of smooth endoplasmic reticulum from which lysosomes appear to develop) (31–33); inosine diphosphatase for endoplasmic reticulum and Golgi apparatus; thiamine pyrophosphatase for Golgi apparatus; acetycholinesterase for Nissl substance (endoplasmic reticulum); NADH-tetra-Nitro BT reductase for mitochondria. All but the mitochondrial enzyme were studied by electron microscopy as well as light microscopy. In chromatolytic perikarya there occur disruption of the rough endoplasmic reticulum in the center of the cell and segregation of the remainder to the cell periphery. Golgi apparatus, GERL, mitochondria and lysosomes accumulate in the central region of the cell. GERL is prominent in both normal and operated perikarya. Electron microscopic images suggest that its smooth endoplasmic reticulum produces a variety of lysosomes in several ways: (a) coated vesicles that separate from the reticulum; (b) dense bodies that arise from focal areas dilated with granular or membranous material; (c) "multivesicular bodies" in which vesicles and other material are sequestered; (d) autophagic vacuoles containing endoplasmic reticulum and ribosomes, presumably derived from the Nissl material, and mitochondria. The number of autophagic vacuoles increases following operation.

scholarly journals Inhibition by colchicine of fibrinogen translocation in hepatocytes.

1975 ◽  
Vol 67 (1) ◽  
pp. 237-243 ◽  
Author(s):  
G Feldmann ◽  
M Maurice ◽  
C Sapin ◽  
J P Benhamou
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Rough Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
Direct Action ◽  
Intraperitoneal Administration ◽  
Cytoplasmic Translocation

In the rat, 8 h after intraperitoneal administration of colchicine, fibrinogen (detected by antirat fibrinogen antibodies labeled with peroxidase) accumulated in the lumina of the rough endoplasmic reticulum of the hepatocytes; 16 and 24 h after colchicine administration, fibrinogen was detected, respectively, in the lumina of the smooth endoplasmic reticulum and in the Golgi apparatus. The effect of colchicine on the cytoplasmic translocation of fibrinogen could be due to a direct action of the drug on the membranes of the endoplasmic reticulum or could be the indirect result of the disruptive action of the drug on the microtubules.

scholarly journals Subcellular localization of the enzyme that forms mannosyl retinyl phosphate from guanosine diphosphate [14C]mannose and retinyl phosphate

1979 ◽  
Vol 180 (3) ◽  
pp. 449-453 ◽  
Author(s):  
M J Smith ◽  
J B Schreiber ◽  
G Wolf
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Subcellular Localization ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Subcellular Distribution ◽  
Smooth Endoplasmic Reticulum ◽  
Marker Enzymes ◽  
Guanosine Diphosphate

The subcellular distribution of the enzyme catalysing the conversion of retinyl phosphate and GDP-[14C]mannose into [14C]mannosyl retinyl phosphate was determined by using subcellular fractions of rat liver. Purity of fractions, as determined by marker enzymes, was 80% or better. The amount of mannosyl retinyl phosphate formed (pmol/min per mg of protein) for each fraction was: rough endoplasmic reticulum 0.48 +/- 0.09 (mean +/- S.D.); smooth membranes (consisting of 60% smooth endoplasmic reticulum and 40% Golgi apparatus), 0.18 +/- 0.03; Golgi apparatus, 0.13 +/- 0.03; and plasma membrane 0.02.

Induction of melanogenesis in the epidermal melanoblasts of newborn mouse skin by MSH

Development ◽  
1977 ◽  
Vol 37 (1) ◽  
pp. 79-90
Author(s):  
Tomohisa Hirobe ◽  
Takuji Takeuchi
Keyword(s):  
Microscopic Observation ◽  
Mouse Skin ◽  
Electron Microscopic Observation ◽  
Newborn Mouse ◽  
Electron Microscopic ◽  
Newborn Mice

The number of melanocytes positive to the dopa reaction in the epidermis was shown to increase after newborn mice were injected with α-MSH or DBc-AMP. The agents seemed to induce the initiation of melanogenesis in the pre-existing melanoblasts. Electron-microscopic observation also demonstrated that α-MSH induced not only maturation of melanosomes but also the formation of melanosomes.

Hepatic Ultrastructure Changes Induced by Lithocholic Acid

1967 ◽  
Vol 25 ◽  
pp. 162-163 ◽  
Author(s):  
F. G. Zaki
Keyword(s):  
Endoplasmic Reticulum ◽  
Lithocholic Acid ◽  
Smooth Endoplasmic Reticulum ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Electron Microscopic ◽  
Hydropic Degeneration ◽  
Hepatic Cells ◽  
Low Protein ◽  
Microscopic Studies

Addition of lithocholic acid (LCA), a naturally occurring bile acid in mammals, to a low protein diet fed to rats induced marked inflammatory reaction in the hepatic cells followed by hydropic degeneration and ductular cell proliferation. These changes were accompanied by dilatation and hyperplasia of the common bile duct and formation of “gallstones”. All these changes were reversible when LCA was withdrawn from the low protein diet except for the hardened gallstones which persisted.Electron microscopic studies revealed marked alterations in the hepatic cells. Early changes included disorganization, fragmentation of the rough endoplasmic reticulum and detachment of its ribosomes. Free ribosomes, either singly or arranged in small clusters were frequently seen in most of the hepatic cells. Vesiculation of the smooth endoplasmic reticulum was often encountered as early as one week after the administration of LCA (Fig. 1).

Spermatogenesis in the Dragonfly with Particular Reference to the Cytoplasmic Organelles

1972 ◽  
Vol 30 ◽  
pp. 110-111
Author(s):  
Sant S. Sekhon
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Mature Sperm ◽  
Electron Microscopic ◽  
Cytoplasmic Organelles ◽  
Microscopic Studies ◽  
Insect Sperm ◽  
Large Round

Although there have been numerous studies concerning the morphogenetic changes accompanying the maturation of insect sperm, only a few deal with the sperm differentiation in the dragonflies. In two recent electron microscopic studies Kessel, has comprehensively treated the erlationship of microtubules to the nucleus and mid-piece structures during spermiogenesis in the dragonfly. The purpose of this study is to follow the sequential nuclear and cytoplasmic changes which accompany the differentiation of spermatogonium into a mature sperm during spermatogenesis in the dragonfly (Aeschna sp.).The dragonfly spermatogonia are characterized by large round nuclei. Loosely organized chromatin is usually unevenly distributed within the spermatogonial nuclei. The scant cytoplasm surrounding the nucleus contains mitochondria, the Golgi apparatus, elements of endoplasmic reticulum and numerous ribosomes (Fig. 1).

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