scholarly journals NEW OBSERVATIONS ON MICROBODIES

1970 ◽  
Vol 45 (1) ◽  
pp. 118-129 ◽  
Author(s):  
Peter G. Legg ◽  
Richard L. Wood

The liver of male rats has been studied after CPIB stimulation by using the peroxidase reaction for localizing catalase in hepatic cells. CPIB administration leads to an increase in the number of microbodies, and it is suggested that one mechanism by which microbody proliferation occurs is a process of fragmentation or budding from preexisting microbodies. Reaction product was observed not only within the microbody matrix, but outside the limiting membrane of the microbody and in association with ribosomes of adjacent rough endoplasmic reticulum. This localization of reaction product is interpreted as evidence that catalase after synthesis on rough endoplasmic reticulum may accumulate near microbodies and may be transferred directly into these organelles without traversing the cisternae of the endoplasmic reticulum or Golgi apparatus.

1970 ◽  
Vol 45 (3) ◽  
pp. 576-585 ◽  
Author(s):  
Richard L. Wood ◽  
Peter G. Legg

The in vivo effects of 3-amino-1,2,4-triazole (AT) on the fine structure of microbodies in hepatic cells of male rats has been studied by the peroxidase-staining technique. Within 1 hr of intraperitoneal injection AT abolishes microbody peroxidase-staining, and the return of staining coincides temporally with the known pattern of return of catalase activity following AT inhibition; this is further evidence that the peroxidase staining of microbodies is due to catalase activity. Peroxidase staining reappears in the microbody matrix without evidence of either massive degradation or rapid proliferation of the organelles. Furthermore, during the period of return of activity, ribosomal staining occurs adjacent to microbodies whose matrix shows little or no peroxidase staining. These observations are interpreted as evidence that (a) catalase is capable of entering preexisting microbodies without traversing the cisternae of the rough endoplasmic reticulum or the Golgi apparatus, and that (b) the ribosomal staining is probably not cytochemical diffusion artifact and may represent a localized site of synthesis or activation of catalase.


1984 ◽  
Vol 32 (6) ◽  
pp. 649-654 ◽  
Author(s):  
M Hayashi ◽  
H Shima ◽  
K Hayashi ◽  
R L Trelstad ◽  
P K Donahoe

Mullerian Inhibiting Substance (MIS) has been localized in the Sertoli cells of the neonatal calf testis using preembedding immunoperoxidase techniques and a monoclonal antibody which almost completely blocks the biological activity of MIS. Both the peroxidase-labeled antibody method using a peroxidase-conjugated F(ab')2 fragment of IgG as a second antibody and the unlabeled antibody peroxidase-antiperoxidase (PAP) method using Fab fragments of the PAP complex were employed. With both methods, MIS was demonstrated within the cisternae of the rough endoplasmic reticulum (RER) and the Golgi apparatus. In the Golgi, MIS was concentrated in the transmost cisternae especially at their peripheral expansions. This study indicates that MIS is synthesized in the RER and transported to the Golgi apparatus, presumably for glycosidation, before secretion from Golgi derived vacuoles.


1978 ◽  
Vol 34 (1) ◽  
pp. 53-63
Author(s):  
C.J. Flickinger

The appearance of enzymic activity during the development of the Golgi apparatus was studied by cytochemical staining of renucleated amoebae. In cells enucleated for 4 days, there was a great decline in size and number of Golgi bodies, or dictyosomes. Subsequent renucleation by nuclear transplantation resulted in a regeneration of Golgi bodies. Samples of amoebae were fixed and incubated for cytochemical staining at intervals of 1, 6, or 24 h after renucleation. Enzymes selected for study were guanosine diphosphatase (GDPase), esterase, and thiamine pyrophosphatase (TPPase). All three were found in the Golgi apparatus of normal amoebae but they differed in their overall intracellular distribution. GDPase was normally present at the convex pole of the Golgi apparatus, in rough endoplasmic reticulum, and in the nuclear envelope. In amoebae renucleated for 1 h, light reaction product for GDPase was present throughout the small stacks of cisternae that represented the forming Golgi apparatus. By 6 h following the operation GDPase reaction product was concentrated at the convex pole of the Golgi apparatus. Esterase, which was distributed throughout the stacks of normal Golgi cisternae, displayed a similar distribution in the forming Golgi bodies as soon as they were visible. TPPase was normally present in the Golgi apparatus but was not found in the endoplasmic reticulum. In contrast to the other enzymes, TPPase reaction product was absent from the forming Golgi apparatus 1 and 6 h after renucleation, and did not appear in the Golgi apparatus until 24 h after operation. Thus, enzymes held in common between the rough endoplasmic reticulum and the Golgi apparatus were present in the forming Golgi apparatus as soon as it was detectable, but an enzyme cytochemically localized to the Golgi apparatus only appeared later in development of the organelle. It is suggested that Golgi membranes might be derived from the endoplasmic reticulum and thus immediately contain endoplasmic reticulum enzymes, while Golgi-specific enzymes are added later in development.


1971 ◽  
Vol 51 (3) ◽  
pp. 596-610 ◽  
Author(s):  
K. Nakagami ◽  
H. Warshawsky ◽  
C. P. Leblond

The parathyroid glands of young rats were radioautographed after a single injection of the protein precursor tyrosine-3H in the hope of identifying the sites of synthesis and migration of newly formed protein in the gland cells. The same procedure was used after injection of the glycoprotein precursor galactose-3H. As early as 2 min after intravenous injection of tyrosine-3H, the label was mainly found in the rough endoplasmic reticulum suggesting that cisternal ribosomes are sites of protein synthesis. By 5 and 10 min, much of the label had migrated from the rough endoplasmic reticulum into the Golgi apparatus. By 20 and 30 min, some label had migrated from there into secretory granules. By 45 min and 1 hr, the label content of the cell had decreased, indicating release of labeled material outside the cell. At 2 min after intravenous injection of galactose-3H, the label was mainly present in the Golgi apparatus, where presumably galactose is taken up into glycoprotein. By 10 min, some label appeared in secretion granules and by 30 min release of the material to the outside of the cell was under way. In conclusion, it is likely that the tyrosine-labeled protein material consists mainly of the parathyroid hormone. The galactose-labeled carbohydrate material would be either associated with the hormone in the cell or be part of a distinct glycoprotein which may be the one present on the outer surface of the plasma membrane (cell coat).


1984 ◽  
Vol 68 (1) ◽  
pp. 83-94
Author(s):  
C.J. Flickinger

The production, transport, and disposition of material labelled with [3H]mannose were studied in microsurgically enucleated and control amoebae. Cells were injected with the precursor and samples were prepared for electron-microscope radioautography at intervals, up to 24 h later. Control cells showed heavy labelling of the rough endoplasmic reticulum and the Golgi apparatus at early intervals after injection. Later, labelling of groups of small vesicles increased, and the percentage of grains over the cell surface peaked 12 h after administration of the precursor. Two major changes were detected in enucleate amoebae. First, the kinetics of labelling of cell organelles with [3H]mannose were altered in the absence of the nucleus. The Golgi apparatus and cell surface both displayed maximal labelling at later intervals in enucleates, and the percentage of grains over the rough endoplasmic reticulum varied less with time in enucleated than in control cells. Second, the distribution of radioactivity was altered. A greater percentage of grains was associated with lysosomes in enucleates than in control cells. The change in the kinetics of labelling of the endoplasmic reticulum, Golgi apparatus and cell surface indicates that intracellular transport of surface material was slower in the absence of the nucleus. It is suggested that this is related to the decreased motility of enucleate cells.


1969 ◽  
Vol 43 (2) ◽  
pp. 289-311 ◽  
Author(s):  
P. Whur ◽  
Annette Herscovics ◽  
C. P. Leblond

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.


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