Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-25T07:36:02.217Z Has data issue: false hasContentIssue false

Constitutive magnification by the Ybb− chromosome of Drosophila melanogaster

Published online by Cambridge University Press:  14 April 2009

Donald J. Komma
Affiliation:
Department of Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
Susan J. Glass
Affiliation:
Department of Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
Sharyn A. Endow
Affiliation:
Department of Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Ybb− is an rDNA-deficient chromosome of Drosophila that has often been used in magnification experiments to induce high-frequency reversion of bobbed (bb) chromosomes. We observed previously that Ybb− causes ring chromosome loss even when the rings are bb+, suggesting that Ybb− induces magnifying sister chromatid exchanges in bb+ rings. Here we show that the Ybb- chromosome causes low levels of bb magnification in bb+ flies. We refer to the ability of Ybb− to bypass the rDNA deficiency requirement for magnification as ‘constitutive’ magnification. We have magnified the ribosomal genes on the Ybb− chromosome and analysed the revertant chromosomes using genetic and molecular methods. We find that magnified Ybb− chromosomes also exhibit constitutive magnifier activity. Molecular analysis shows that both type 1 and type 2 intron+ ribosomal gene repeats are associated with magnified Ybb− chromosomes. Type 2 introns have been described previously in the rDNA of both X and Y chromosomes. However, type 1 intervening sequences are thought to be present only in X, but not Y, ribosomal genes. Some of the Ybb− type 1 insertions differ from those present in the rDNA of X chromosomes in that they contain an EcoRl site, and some may be present in tandem arrays. The constitutive magnifier activity of Ybb− may reside either in the structurally unusual ribosomal gene intervening sequences associated with the chromosome, or in the locus on YL that is required for magnification to occur.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1993

References

Bridges, C. B. & Brehme, K. S. (1944). The mutants of Drosophila melanogaster. Carnegie Institution of Washington Publication 552.Google Scholar
Dawid, I. B. & Rebbert, M. L. (1981). Nucleotide sequences at the boundaries between gene and insertion regions in the rDNA of Drosophila melanogaster. Nucleic Acids Research 9, 50115020.CrossRefGoogle Scholar
Dawid, I. B. & Wellauer, P. K. (1977). Ribosomal DNA and related sequences in Drosophila melanogaster. Cold Spring Harbor Symposia on Quantitative Biology 42, 11851194.CrossRefGoogle Scholar
Dawid, I. B., Wellauer, P. K. & Long, E. O. (1978). Ribosomal DNA in Drosophila melanogaster. I. Isolation and characterization of cloned fragments. Journal of Molecular Biology 126, 749768.CrossRefGoogle ScholarPubMed
de Cicco, D. V. & Glover, D. M. (1983). Amplification of rDNA and type 1 sequences in Drosophila males deficient in rDNA. Cell 32, 12171225.CrossRefGoogle Scholar
Endow, S. A. (1982a). Molecular characterization of ribosomal genes on the Ybb− chromosome of Drosophila melanogaster. Genetics 102, 9199.CrossRefGoogle ScholarPubMed
Endow, S. A. (1982b). Polytenization of the ribosomal genes on the X and Y chromosomes of Drosophila melanogaster. Genetics 100, 375385.CrossRefGoogle ScholarPubMed
Endow, S. A. & Atwood, K. C. (1988). Magnification: gene amplification by an inducible system of sister chromatid exchange. Trends in Genetics 4, 348351.CrossRefGoogle ScholarPubMed
Endow, S. A. & Glover, D. M. (1979). Differential replication of ribosomal gene repeats in polytene nuclei of Drosophila. Cell 17, 597605.CrossRefGoogle ScholarPubMed
Endow, S. A. & Komma, D. J. (1986). One-step and stepwise magnification of a bobbed lethal chromosome in Drosophila melanogaster. Genetics 114, 511523.CrossRefGoogle ScholarPubMed
Endow, S. A., Komma, D. J. & Atwood, K. C. (1984). Ring chromosomes and rDNA magnification in Drosophila. Genetics 108, 969983.CrossRefGoogle ScholarPubMed
Feinberg, A. P. & Vogelstein, B. (1984). A technique for radiolabelling DNA restriction endonuclease fragments to high specific activity. Analytical Biochemistry 137, 266267.Google ScholarPubMed
Glover, D. M. & Hogness, D. S. (1977). A novel arrangement of the 18S and 28S sequences in a repeating unit of Drosophila melanogaster rDNA. Cell 10, 167176.CrossRefGoogle Scholar
Hawley, R. S. & Tartof, K. D. (1983). The effect of mei-41 on rDNA redundancy in Drosophila melanogaster. Genetics 104, 6380.CrossRefGoogle ScholarPubMed
Hawley, R. S. & Tartof, K. D. (1985). A two-stage model for the control of rDNA magnification. Genetics 109, 691700.CrossRefGoogle ScholarPubMed
Jakubczak, J. L., Xiong, Y. & Eickbush, T. H. (1990). Type I (R1) and type II (R2) ribosomal DNA insertions of Drosophila melanogaster are retrotransposable elements closely related to those of Bombyx mori. Journal of Molecular Biology 212, 3752.CrossRefGoogle ScholarPubMed
Komma, D. J. & Endow, S. A. (1986). Magnification of the ribosomal genes in female Drosophila melanogaster. Genetics 114, 859874.CrossRefGoogle ScholarPubMed
Komma, D. J. & Endow, S. A. (1987). Incomplete Y chromosomes promote magnification in male and female Drosophila. Proceedings of the National Academy of Sciences U.S.A. 84, 23822386.CrossRefGoogle ScholarPubMed
Komma, D. J., Graves, H. & Endow, S. A. (1989). Mutant alleles of the meiotic locus, mei-9, differ in degree of effects on rod chromosome magnification and ring chromosome transmission in Drosophila. Genetical Research 53, 155161.CrossRefGoogle ScholarPubMed
Lindsley, D. L. & Grell, E. H. (1968). Genetic variations of Drosophila melanogaster: Carnegie Institution of Washington Publication 627.Google Scholar
Lindsley, D. L. & Zimm, G. G. (1992). The genome of Drosophila melanogaster. Academic Press, San Diego.Google Scholar
Long, E. O., Rebbert, M. L. & Dawid, I. B. (1980). Structure and expression of ribosomal RNA genes of Drosophila melanogaster interrupted by type 2 insertions. Cold Spring Harbor Symposia of Quantitative Biology 45, 667672.CrossRefGoogle Scholar
Maniatis, T., Fritsch, E. F. & Sambrook, J. (1982). Molecular cloning — a laboratory manual. Cold Spring Harbor Laboratory, New York.Google Scholar
Murray, N. E. (1983). Phage lambda and molecular cloning. The bacteriophage lambda. Cold Spring Harbor Laboratory, New York, 395432.Google Scholar
Ritossa, F. (1976). The bobbed locus. The genetics and biology of Drosophila. Academic Press, London, pp. 801846.Google Scholar
Ritossa, F. M. (1968). Unstable redundancy of genes for ribosomal RNA. Proceedings of the National Academy of Sciences U.S.A. 60, 509516.CrossRefGoogle ScholarPubMed
Roiha, H. & Glover, D. M. (1980). Characterisation of complete type II insertions in cloned segments of ribosomal DNA from Drosophila melanogaster. Journal of Molecular Biology 140, 341355.CrossRefGoogle Scholar
Roiha, H., Miller, J. R., Woods, L. C. & Glover, D. M. (1981). Arrangements and rearrangements of sequences flanking the two types of rDNA insertion in D. melanogaster. Nature 290, 749753.CrossRefGoogle ScholarPubMed
Spear, B. B. (1974). The genes for ribosomal RNA in diploid and polytene chromosomes of Drosophila melanogaster. Chromosomal, 48, 159179.CrossRefGoogle ScholarPubMed
Tartof, K. D. (1973). Unequal mitotic sister chromatid exchange and disproportionate replication as mechanisms regulating ribosomal RNA gene redundancy. Cold Spring Harbor Symposia of Quantitative Biology 38, 491–00.CrossRefGoogle Scholar
Tartof, K. D. (1974). Unequal mitotic sister chromatid exchange as the mechanism of ribosomal RNA gene magnification. Proceedings of the National Academy of Sciences U.S.A. 71, 12721276.CrossRefGoogle ScholarPubMed
Wellauer, P. K. & Dawid, I. B. (1978). Ribosomal DNA in Drosophila melanogaster. II. Heteroduplex mapping of cloned and uncloned rDNA. Journal of Molecular Biology 126, 769782.CrossRefGoogle ScholarPubMed
Xiong, Y. & Eickbush, T. H. (1988). Functional expression of a sequence-specific endonuclease encoded by the retrotransposon R2Bm. Cell 55, 235246.CrossRefGoogle ScholarPubMed