Tracing of RNA from a Puff in the Polytene Chromosomes to the Cytoplasm in Chironomus tentans Salivary Gland Cells

Nature ◽  
1973 ◽  
Vol 242 (5392) ◽  
pp. 51-53 ◽  
Author(s):  
B. LAMBERT
Keyword(s):  
Salivary Gland ◽  
Polytene Chromosomes ◽  
Chironomus Tentans ◽  
Gland Cells ◽  
Salivary Gland Cells

Microinjection of anti-topoisomerase I immunoglobulin G into nuclei of Chironomus tentans salivary gland cells leads to blockage of transcription elongation

1987 ◽  
Vol 7 (12) ◽  
pp. 4308-4316
Author(s):  
E Egyházi ◽  
E Durban
Keyword(s):  
Salivary Gland ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Immunoglobulin G ◽  
Topoisomerase I ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Transcriptional Process

Purified anti-topoisomerase I immunoglobulin G (IgG) was microinjected into nuclei of Chironomus tentans salivary gland cells, and the effect on DNA transcription was investigated. Synthesis of nucleolar preribosomal 38S RNA by RNA polymerase I and of chromosomal Balbiani ring RNA by RNA polymerase II was inhibited by about 80%. The inhibitory action of anti-topoisomerase I IgG could be reversed by the addition of exogenous topoisomerase I. Anti-topoisomerase I IgG had less effect on RNA polymerase II-promoted activity of other less efficiently transcribing heterogeneous nuclear RNA genes. The pattern of inhibition of growing nascent Balbiani ring chains indicated that the transcriptional process was interrupted at the level of chain elongation. The highly decondensed state of active Balbiani ring chromatin, however, remained unaffected after injection of topoisomerase I antibodies. These data are consistent with the interpretation that topoisomerase I is an essential component in the transcriptional process but not in the maintenance of the decondensed state of active chromatin.

Electrophoretic characterization of nucleolar RNA from Chironomus tentans salivary gland cells

1970 ◽  
Vol 51 (2) ◽  
pp. 327-340 ◽  
Author(s):  
U. Ringborg ◽  
B. Daneholt ◽  
J.-E. Edström ◽  
E. Egyházi ◽  
B. Lambert
Keyword(s):  
Salivary Gland ◽  
Chironomus Tentans ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Nucleolar Rna

scholarly journals Microinjection of anti-topoisomerase I immunoglobulin G into nuclei of Chironomus tentans salivary gland cells leads to blockage of transcription elongation.

1987 ◽  
Vol 7 (12) ◽  
pp. 4308-4316 ◽  
Author(s):  
E Egyházi ◽  
E Durban
Keyword(s):  
Salivary Gland ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Immunoglobulin G ◽  
Topoisomerase I ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Transcriptional Process

Purified anti-topoisomerase I immunoglobulin G (IgG) was microinjected into nuclei of Chironomus tentans salivary gland cells, and the effect on DNA transcription was investigated. Synthesis of nucleolar preribosomal 38S RNA by RNA polymerase I and of chromosomal Balbiani ring RNA by RNA polymerase II was inhibited by about 80%. The inhibitory action of anti-topoisomerase I IgG could be reversed by the addition of exogenous topoisomerase I. Anti-topoisomerase I IgG had less effect on RNA polymerase II-promoted activity of other less efficiently transcribing heterogeneous nuclear RNA genes. The pattern of inhibition of growing nascent Balbiani ring chains indicated that the transcriptional process was interrupted at the level of chain elongation. The highly decondensed state of active Balbiani ring chromatin, however, remained unaffected after injection of topoisomerase I antibodies. These data are consistent with the interpretation that topoisomerase I is an essential component in the transcriptional process but not in the maintenance of the decondensed state of active chromatin.

scholarly journals NUCLEOLAR-DERIVED RIBONUCLEIC ACID IN CHROMOSOMES, NUCLEAR SAP, AND CYTOPLASM OF CHIRONOMUS TENTANS SALIVARY GLAND CELLS

1971 ◽  
Vol 51 (2) ◽  
pp. 355-368 ◽  
Author(s):  
U. Ringborg ◽  
L. Rydlander
Keyword(s):  
Molecular Weight ◽  
Salivary Gland ◽  
High Molecular Weight ◽  
Ribosomal Rna ◽  
Chironomus Tentans ◽  
Gland Cells ◽  
Composite Gels ◽  
Salivary Gland Cells

The distribution of monodisperse high molecular weight RNA (38, 30, 28, 23, and 18S RNA) was studied in the salivary gland cells of Chironomus tentans. RNA labeled in vitro and in vivo with tritiated cytidine and uridine was isolated from microdissected nucleoli, chromosomes, nuclear sap, and cytoplasm and analyzed by electrophoresis on agarose-acrylamide composite gels. As shown earlier, the nucleoli contain labeled 38, 30, and 23S RNA. In the chromosomes, labeled 18S RNA was found in addition to the 30 and 23S RNA previously reported. The nuclear sap contains labeled 30 and 18S RNA, and the cytoplasm labeled 28 and 18S RNA. On the basis of the present and earlier analyses, it was concluded that the chromosomal monodisperse high molecular weight RNA fractions (a) show a genuine chromosomal localization and are not due to unspecific contamination, (b) are not artefacts caused by in vitro conditions, but are present also in vivo, and (c) are very likely related to nucleolar and cytoplasmic (pre)ribosomal RNA. The 30 and 23S RNA components are likely to be precursors to 28 and 18S ribosomal RNA. The order of appearance of the monodisperse high molecular weight RNA fractions in the nucleus is in turn and order: (a) nucleolus, (b) chromosomes, and (c) nuclear sap. Since both 23 and 18S RNA are present in the chromosomes, the conversion to 18S RNA may take place there. On the other hand, 30S RNA is only found in the nucleus while 28S RNA can only be detected in the cytoplasm, suggesting that this conversion takes place in connection with the exit of the molecule from the nucleus.

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