Abstract
The sequence-nonhomologous rDNA spacers of D. melanogaster and D. virilis exhibit remarkably similar organizations and transcription capabilities. In spacers of both species, tandemly repeated sequences are present upstream of the beginning of the pre-rRNA coding region, and the repeats are capable of transcriptional activity. Short, nuclear transcripts homologous to the spacer repeats have been identified by S1 nuclease protection experiments and by northern blot analyses. Although spacer transcripts are rare in steady state RNA populations, the presence of multiple promoter elements may suggest a regulatory role for rDNA spacers.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Busby S. J., Reeder R. H. Spacer sequences regulate transcription of ribosomal gene plasmids injected into Xenopus embryos. Cell. 1983 Oct;34(3):989–996. doi: 10.1016/0092-8674(83)90556-1. [DOI] [PubMed] [Google Scholar]
- Dawid I. B., Wellauer P. K., Long E. O. Ribosomal DNA in Drosophila melanogaster. I. Isolation and characterization of cloned fragments. J Mol Biol. 1978 Dec 25;126(4):749–768. doi: 10.1016/0022-2836(78)90018-9. [DOI] [PubMed] [Google Scholar]
- Jolly D. J., Thomas C. A., Jr Nuclear RNA transcripts from Drosophila melanogaster ribosomal RNA genes containing introns. Nucleic Acids Res. 1980 Jan 11;8(1):67–84. doi: 10.1093/nar/8.1.67. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kohorn B. D., Rae P. M. Nontranscribed spacer sequences promote in vitro transcription of Drosophila ribosomal DNA. Nucleic Acids Res. 1982 Nov 11;10(21):6879–6886. doi: 10.1093/nar/10.21.6879. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Long E. O., Dawid I. B. Restriction analysis of spacers in ribosomal DNA of Drosophila melanogaster. Nucleic Acids Res. 1979 Sep 11;7(1):205–215. doi: 10.1093/nar/7.1.205. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Long E. O., Rebbert M. L., Dawid I. B. Nucleotide sequence of the initiation site for ribosomal RNA transcription in Drosophila melanogaster: comparison of genes with and without insertions. Proc Natl Acad Sci U S A. 1981 Mar;78(3):1513–1517. doi: 10.1073/pnas.78.3.1513. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mandal R. K., Dawid I. B. The nucleotide sequence at the transcription termination site of ribosomal RNA in Drosophila melanogaster. Nucleic Acids Res. 1981 Apr 24;9(8):1801–1811. doi: 10.1093/nar/9.8.1801. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maxam A. M., Gilbert W. Sequencing end-labeled DNA with base-specific chemical cleavages. Methods Enzymol. 1980;65(1):499–560. doi: 10.1016/s0076-6879(80)65059-9. [DOI] [PubMed] [Google Scholar]
- McKnight S. L., Gavis E. R., Kingsbury R., Axel R. Analysis of transcriptional regulatory signals of the HSV thymidine kinase gene: identification of an upstream control region. Cell. 1981 Aug;25(2):385–398. doi: 10.1016/0092-8674(81)90057-x. [DOI] [PubMed] [Google Scholar]
- Miller J. R., Hayward D. C., Glover D. M. Transcription of the 'non-transcribed' spacer of Drosophila melanogaster rDNA. Nucleic Acids Res. 1983 Jan 11;11(1):11–19. doi: 10.1093/nar/11.1.11. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Morgan G. T., Roan J. G., Bakken A. H., Reeder R. H. Variations in transcriptional activity of rDNA spacer promoters. Nucleic Acids Res. 1984 Aug 10;12(15):6043–6052. doi: 10.1093/nar/12.15.6043. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Moss T. A transcriptional function for the repetitive ribosomal spacer in Xenopus laevis. Nature. 1983 Mar 17;302(5905):223–228. doi: 10.1038/302223a0. [DOI] [PubMed] [Google Scholar]
- Rae P. M., Barnett T., Murtif V. L. Nontranscribed spacers in Drosophila ribosomal DNA. Chromosoma. 1981;82(5):637–655. doi: 10.1007/BF00285773. [DOI] [PubMed] [Google Scholar]
- Reeder R. H., Roan J. G., Dunaway M. Spacer regulation of Xenopus ribosomal gene transcription: competition in oocytes. Cell. 1983 Dec;35(2 Pt 1):449–456. doi: 10.1016/0092-8674(83)90178-2. [DOI] [PubMed] [Google Scholar]
- Reeder R. H., Roan J. G. The mechanism of nucleolar dominance in Xenopus hybrids. Cell. 1984 Aug;38(1):38–44. doi: 10.1016/0092-8674(84)90524-5. [DOI] [PubMed] [Google Scholar]
- Tavitian A., Uretsky S. C., Acs G. The effect of toyocamycin on cellular RNA synthesis. Biochim Biophys Acta. 1969 Mar 18;179(1):50–57. doi: 10.1016/0005-2787(69)90121-x. [DOI] [PubMed] [Google Scholar]