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The effect of actinomycin D on the nucleolus and on pigment synthesis in pigment cells of Xenopus laevis: an ultrastructural study.
Kramer B
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The effect of AMD on the nucleolus and on melanogenesis in differentiating pigment cells of Xenopus laevis was investigated in cultured neural crest cells. Cultures were treated with either 2 or 10 microgram/ml AMD for 41/2 hours. Following treatment the antibiotic was removed. Observations of the cells were made with both scanning and transmission electron microscopes. Actinomycin D almost entirely stopped pigment formation in neural crest cultures during treatment. The morphological sequence in the formation of melanin granules in the untreated pigment cells appears to be as follows: The earliest identifiable premelanosome is membrane-bound and contains very thin laminae and/or small vesciles. The premelanosomes become until they are approximately the size of mature melanin granules and there is thickening of the laminae, which appear to have a periodic substructure. The cells eventually become packed with electron-dense melanin granules. Compared with controls, the cytoplasm of treated cells showed a greater abundance of smooth- than of fuzzy-membraned vesicles, less rough endoplasmic reticulum, dilatation of the Golgi cisternae, and a smaller number of premelanosomes. The necleolus showed segregation and blebbing of its components, decrease in size and even disappearance; sometimes confluence of the components occurred. The most consistent morphological effect of AMD on the nucleolus was the separation of the fibrillar and granular areas. The granular component appeared to undergo marked changes in size and arrangement and is thought to be the source of ribosomal RNA precursors. The alteration in size of the outer component of the nucleolus went hand in hand with disappearance of free ribosomes from the cytoplasm of treated cells and inhibition of pigment synthesis.
Andrew,
Hanging drop culture of Xenopus laevis neural crest.
1969, Pubmed,
Xenbase
Andrew,
Hanging drop culture of Xenopus laevis neural crest.
1969,
Pubmed
,
Xenbase
Boyde,
Scanning electron microscopy of cells in culture.
1972,
Pubmed
Eppig,
Melanogenesis in amphibians. I. A study of the fine structure of the normal and phenylthiourea-treated pigmented epithelium in Rana pipiens tadpole eyes.
1970,
Pubmed
Eppig,
The distribution of melanosomes in larvae reared from normal and from pigmentless eggs of Xenopus laevis.
1971,
Pubmed
,
Xenbase
Eppig,
Melanogenesis in amphibians. 3. The buoyant density of oocyte and larval xenopus laevis melanosomes and the isolation of oocyte melanosomes from the eyes of PTU-treated larvae.
1970,
Pubmed
,
Xenbase
Fitzpatrick,
Terminology of vertebrate melanin-containing cells: 1965.
1966,
Pubmed
GIRARD,
THE EFFECT OF ACTINOMYCIN ON RIBOSOME FORMATION IN HELA CELLS.
1964,
Pubmed
GOLDSTEIN,
In vitro studies with HeLa cell line sensitive and resistant to actinomycin D.
1960,
Pubmed
HACKMANN,
The effect of actinomycins on experimental tumors.
1960,
Pubmed
Hearing,
The fine structure of melanogenesis in coat color mutants of the mouse.
1973,
Pubmed
JACOB,
ELECTRON MICROSCOPE STUDIES ON SALIVARY GLAND CELLS. IV. THE NUCLEUS OF SMITTIA PARTHENOGENETICA (CHIRONOMIDAE) WITH SPECIAL REFERENCE TO THE NUCLEOLUS AND THE EFFECTS OF ACTINOMYCIN THEREON.
1964,
Pubmed
Kramer,
The effect of actinomycin D on developing pigment cells of Xenopus laevis.
1972,
Pubmed
,
Xenbase
Maul,
On the possible function of coated vesicles in melanogenesis of the regenerating fowl feather.
1971,
Pubmed
Niu,
The Differentiation of Gastrula Ectoderm in Medium Conditioned by Axial Mesoderm.
1953,
Pubmed
Penman,
POLYRIBOSOMES IN NORMAL AND POLIOVIRUS-INFECTED HELA CELLS AND THEIR RELATIONSHIP TO MESSENGER-RNA.
1963,
Pubmed
Penman,
RNA metabolism in the HeLa cell nucleus.
1966,
Pubmed
Phillips,
Nucleoli of diploid cell strains. Thei normal ultrastructure and the effects of toyocamycin and actinomycin D.
1971,
Pubmed
REYNOLDS,
Nucleolars "caps'--a morphologic entity produced by the carcinogen 4-nitroquinoline N-oxide.
1963,
Pubmed
Recher,
A reevaluation of nuclear and nucleolar changes induced in vitro by actinomycin D.
1971,
Pubmed
SCHOEFL,
THE EFFECT OF ACTINOMYCIN D ON THE FINE STRUCTURE OF THE NUCLEOLUS.
1964,
Pubmed
STEVENS,
THE EFFECT OF ACTINOMYCIN D ON NUCLEOLAR AND NUCLEAR FINE STRUCTURE IN THE SALIVARY GLAND CELL OF HIRONOMUS THUMMI.
1964,
Pubmed
Sameshima,
The effect of actinomycin D on nucleolar formationin early Xenopus laevis gastrulae.
1970,
Pubmed
,
Xenbase
Seiji,
Intracellular localization of tyrosinase and site of melanin formation in melanocyte.
1965,
Pubmed
Smuckler,
The early effects of actinomycin on rat liver. Changes in ribosomes and polysomes.
1965,
Pubmed
WETTSTEIN,
Ribosomal aggregate engaged in protein synthesis: characterization of the ergosome.
1963,
Pubmed
