Der Nucleolus und seine Beziehungen zu den Ribosomen des Cytoplasmas. Eine Untersuchung an den Malpighischen Gef�ssen von Drosophila melanogaster

Wessing, Armin

doi:10.1007/bf00345642

Cited by 15 publications

(2 citation statements)

References 164 publications

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“…A similar assumption was expressed by WESSING (1965) in Drosophila Malpighian tubule cells and by SHIMIZU and ISHII (1965) in nerve cells of the rat hypothalamus.…”

Section: Such Inclusionmentioning

confidence: 79%

A Possible Mechanism for the Nucleolar Extrusion in Nerve Cells of the Mouse Hypothalamus

Sano

Sotokawa

1971

Arch. Histol. Jap., Arch. Histol. Jpn

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Summary. The hypothalamus of adult male mice was investigated with the electron microscope. In all hypothalamic nuclei examined the nerve cells frequently contained nucleolus-like inclusion bodies in the cytoplasm. These inclusion bodies appeared to be composed of the same constituent particles as those of the intranuclear nucleolus. This permits consideration of their probable nuclear origin. The accessory nucleolus, tentatively named in the present paper, appearing to consist of nucleolar material with the association of chromatin was frequently encountered attached to the nuclear membrane and sometimes located at evaginated portions of the nucleus. Moreover, near the nucleus in the cytoplasm, inclusion bodies showing a close resemblance in appearance to the accessory nucleolus except for the absence of the association of chromatin particles were observed to be enveloped with a double membrane probably derived from the nuclear envelope. From these results, it was concluded that the direct translocation of the nucleolar substance of accessory nucleoli into the cytoplasm with an investment of a double nuclear membrane may be possible in nerve cells of the mouse hypothalamus.Intracytoplasmic nucleolus-like inclusion bodies have been reported repeatedly as occurring in various kinds of cells (cf. GRILLO, 1970). They have also been frequently observed in nerve cells, i.e. in the rat sympathetic ganglia (GRILLO, 1970) and in the rat hypothalamic nuclei (BACHRACH, 1957;SAKAI, 1964;KAWABATA, 1965;SHIMIZU and ISHII, 1965). Such inclusion bodies have been assumed to derive from the intranuclear nucleolus, but no direct morphological evidence has been offered. During the course of ultrastructural studies on the mouse hypothalamic nuclei, the present authors have frequently observed nucleolus-like inclusion bodies in nerve cells and further obtained some figures suggestive of a process of nucleolar extrusion. Thus a possible mechanism for the translocation of nucleolar material into the cytoplasm will be proposed in the present paper. Material and MethodsHealthy, adult male SMA strain mice (about 100 days old) were perfused under ether anesthesia from the left ventricle with a formaldehyde-glutaraldehyde fixative (KARNOVSKY, 1965) for 10 minutes.The brains obtained were frontally sliced about 0.5mm in thickness and then left in immersion in the same fixation medium for 3 hours. The tissue slices were washed overnight in a 0.1M phosphate buffer solution containing 7% sucrose. Postfixation was done with 1% OsO4 (Veronal buffer, pH 7.4) for 2 hours. Specimens were then dehydrated with graded acetone solutions and embedded in Epon 812. Thick sections stained with toluidine blue (YAMAMOTO, 1963) were observed with a light microscope for the identification of the hypothalamic nuclei. Thin sections were cut on a Porter Blum MT-1 ultramicrotome equipped 199

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“…A similar assumption was expressed by WESSING (1965) in Drosophila Malpighian tubule cells and by SHIMIZU and ISHII (1965) in nerve cells of the rat hypothalamus.…”

Section: Such Inclusionmentioning

confidence: 79%

A Possible Mechanism for the Nucleolar Extrusion in Nerve Cells of the Mouse Hypothalamus

Sano

Sotokawa

1971

Arch. Histol. Jap., Arch. Histol. Jpn

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“…This may result from separation of the associated chromatin, by which nucleoli adhere tightly to the nuclear membrane (Bernhard, 1966). Since the close apposition of nucleoli to nuclear membranes may represent a means of ready transfer of nucleolar material to ribosomes in the cytoplasm (Shimizu and Ishii, 1965;Wessing, 1965), the loss of eccentricity after feeding azo-dye may accelerate depletion of cytoplasmic ribosomes and the development of hypobasophilia, but the significance of nucleolar position is still conjectural.…”

Section: Early Cytological Changes After Feeding Animals With Azo-dyementioning

confidence: 99%

Quantitative studies of early cytological alterations induced in rat liver by 3′‐methyl‐4‐dimethylaminoazobenzene, as affected by 3‐methylcholanthrene

Harman

1970

The Journal of Pathology

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A new cytoplasmic component in the trophoblast cells of the rat and mouse

Törö¹,

Röhlich²

1966

Anat. Rec.

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Tissue blocks removed from placentas of rats and mice at different gestational age were fixed in either oso4 or glutaraldehyde or both, embedded into Araldite, and thin sections were examined with the electron microscope. A hitherto undescribed cytoplasmic component consisting of convoluted thread-like elements embedded in a clear ground substance has been regularly found in the trophoblast I I cells of rats and mice. The ovoid-shaped cytoplasmic component, termed by us gEomerular body, is about 1 to 1.5 JL in its greatest diameter and is composed of electrondense 400 to 500 A thick threads which appear to have a fine filamentous and granular structure. The threads were often observed in close topographical relationship with free ribosomes. The thread-like elements of the glomerular body were occasionally found dispersed or lined up under the cell membrane of the foctal side of the trophoblast I I cell. In some instances similar structures were observed in the nucleus. The nature and significance of the glomerular body is unknown.In the course of the electron microscopical investigation of the chorioallantoic placenta of rats and mice we found in the trophoblast cells a peculiar cytoplasmic component, which, to our knowledge, has not yet been described. Only one short note is known in the literature on the existence of a similar structure (Enders, '65). On the basis of its shape and convoluted structure it was termed by us "glomerular body."According to the observations of Enders ('65) the ultrastructure of the placenta in the mouse is very similar to that of the rat which has been described in detail by Jollie ('64). The latter author distinguishes four cellular layers separating the maternal blood sinus from the foetal capillary lumen: ( a ) trophoblast I; (b) trophoblast II; ( c ) element III and ( d ) endothelium. According to this terminology we found the glomerular bodies exclusively and characteristically in the trophoblast II,cells. They could first be recognized at the'thirteenth or fourteenth day of gestation, persisted throughout late pregnancy, and were found after birth. MATERIAL AND METHODSThe fine structure of the placenta in rats of increasing gestational age from the twelfth to the twenty-second day and in ANhT. REC., 155: 385-400.mice from the fifteenth and twentieth days post coitum, was observed in electron microgr aphs.Animals were anesthetized by intraperitoneal injection of Narcothion (Bthyl-(1-methyl-propy1)-thiobarbitur acidic sodium, "Sanabo" Wien). Tissue was taken from the superficial and deeper labyrinth near to the junctional zone from each placenta. The blocks were fixed for 1.5 hours in 1% OsO,, buffered to pH 7.4 with Millonig phosphate buffer at 4°C. Some of the placentas were fixed for 3 to 4 hours in 0.14 M or 0.08 M Na-cacodylate-buffered (pH 7.4) 6% glutaraldehyde at room temperature and postfixed as above in 0~0~. The tissue blocks were dehydrated in ethanol and embedded in Araldite. Thin sections were cut on a Porter-Blum and on an OMU-2 ultramicrotome, stained with...

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Der Nucleolus und seine Beziehungen zu den Ribosomen des Cytoplasmas. Eine Untersuchung an den Malpighischen Gef�ssen von Drosophila melanogaster

Cited by 15 publications

References 164 publications

A Possible Mechanism for the Nucleolar Extrusion in Nerve Cells of the Mouse Hypothalamus

A Possible Mechanism for the Nucleolar Extrusion in Nerve Cells of the Mouse Hypothalamus

Quantitative studies of early cytological alterations induced in rat liver by 3′‐methyl‐4‐dimethylaminoazobenzene, as affected by 3‐methylcholanthrene

A new cytoplasmic component in the trophoblast cells of the rat and mouse

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