A peptide-reactive antibody to a Balbiani ring gene product: immunological evidence that a 6.5-kb RNA in Chironomus tentans salivary glands is mRNA for a 180-kDa nonfibrous component of larval secretion

Gene ◽  
1987 ◽  
Vol 55 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Thomas D. Dreesen ◽  
Steven T. Case
Keyword(s):  
Salivary Glands ◽  
Gene Product ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Larval Secretion ◽  
Reactive Antibody

The 75 S RNA transcription unit in Balbiani ring 2 and its relation to chromosome structure

1978 ◽  
Vol 283 (997) ◽  
pp. 383-389 ◽  
Keyword(s):  
Salivary Glands ◽  
Functional Significance ◽  
Chromosome Structure ◽  
Transcription Unit ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Base Pairs ◽  
Primary Transcript ◽  
Rna Transcription ◽  
Available Information

A defined transcription unit in the Balbiani ring 2 (BR 2) region of chromosome IV in the salivary glands of Chironomus tentans has been characterized on the basis of analysis of the corresponding primary transcript, 75 S RNA, and its functional significance. The available information on the transcription unit and its relation to chromosome structure can be summarized in the following way: 1. The size of the 75 S RNA transcription unit in BR 2 is on the order of 30 000 base pairs. 2. The unit is likely to contain a long coding segment (at least 6000 base pairs), probably corresponding to information for salivary polypeptides. 3. The sequences are distributed in more than one chromomere (probably in 3-5 chromomeres). Further studies are needed before it can be stated whether or not there is a simple one-to-one relation between chromomeres and transcription units in the BR 2 region.

scholarly journals Large-sized polysomes in Chironomus tentans salivary glands and their relation to Balbiani ring 75S RNA.

1977 ◽  
Vol 73 (1) ◽  
pp. 149-160 ◽  
Author(s):  
B Daneholt ◽  
K Anderson ◽  
M Fagerlind
Keyword(s):  
Salivary Glands ◽  
Messenger Rna ◽  
High Yield ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Rna Molecules ◽  
Large Size ◽  
Present Information ◽  
Balbiani Rings ◽  
Available Information

Polysomes from the salivary glands of Chironomus tentans were investigated to determine whether Balbiani ring 75S RNA is incorporated into polysomal structures, and thus probably acts as messenger RNA. A new extraction technique for obtaining ribonucleoproteins was applied that gives a high yield of polysomes with only moderate degradation of the cytoplasmic, high molecular weight RNA. The polysomes sedimented in a broad region (200-2,000S) with a peak value of about 700S, which suggested that they were partly of very large sizes. This was confirmed by visualization of the polysomes in the electron microscope: 400S polysomes contained mainly 11-16 ribosomes, and 1,500S polysomes about 60 ribosomes per polysome. However, polysomes containing 100 or more ribosomes were also observed. It was further established that most of the cytoplasmic 75S RNA was located in polysomes, preferentially in the most rapidly sedimenting ones. From the available information on Balbiani ring RNA in cytoplasm and the present demonstration of 75S RNA molecules in polysomes, it was concluded that at least some Balbiani ring RNA, generated as 75S RNA within the Balbiani rings, eventually enters polysomes without being measurably changed in size. The present information on the potential amino acid coding sequences in 75S RNA is discussed in relation to the large size of the polysomes observed.

scholarly journals A novel giant secretion polypeptide in Chironomus salivary glands: implications for another Balbiani ring gene.

1985 ◽  
Vol 101 (3) ◽  
pp. 1044-1051 ◽  
Author(s):  
W Y Kao ◽  
S T Case
Keyword(s):  
Amino Acid ◽  
Nucleotide Sequence ◽  
Salivary Glands ◽  
Cyanogen Bromide ◽  
Tryptic Peptide ◽  
Amino Acid Sequences ◽  
The Other ◽  
Balbiani Ring ◽  
Sequence Organization ◽  
Peptide Maps

Chironomus salivary glands contain a family of high Mr (approximately 1,000 X 10(3)) secretion polypeptides thought to consist of three components: sp-Ia, sp-Ib, and sp-Ic. The use of a new extraction protocol revealed a novel high Mr component, sp-Id. Results of a survey of individual salivary glands indicated that sp-Id was widespread in more than a dozen strains of C. tentans and C. pallidivittatus. Sp-Id was phosphorylated at Ser residues, and a comparison of cyanogen bromide and tryptic peptide maps of 32P-labeled polypeptides suggested that sp-Ia, sp-Ib, and sp-Id are comprised of similar but nonidentical tandemly repeated amino acid sequences. We concluded that sp-Id is encoded by an mRNA whose size and nucleotide sequence organization are similar to Balbiani ring (BR) mRNAs that code for the other sp-I components. Furthermore, parallel repression of sp-Ib and sp-Id synthesis by galactose led us to hypothesize that both of their genes exist within Balbiani ring 2.

A structural analysis of Balbiani ring DNA sequences in Chironomus tentans

Chromosoma ◽  
1981 ◽  
Vol 83 (3) ◽  
pp. 295-313 ◽  
Author(s):  
Adelheid Degelmann ◽  
Cornelis P. Hollenberg
Keyword(s):  
Structural Analysis ◽  
Dna Sequences ◽  
Chironomus Tentans ◽  
Balbiani Ring

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.

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