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. 1992 Jul;131(3):581–592. doi: 10.1093/genetics/131.3.581

Ribosomal DNA Is a Site of Chromosome Breakage in Aneuploid Strains of Neurospora

D K Butler 1
PMCID: PMC1205032  PMID: 1385794

Abstract

In wild-type strains of Neurospora crassa, the rDNA is located at a single site in the genome called the nucleolus organized region (NOR), which forms a terminal segment on linkage group (LG) V. In the quasiterminal translocation strain T(I;V)AR190, most of the right arm of LG I is moved to the distal tip of the NOR, and one or a few rDNA repeat units are moved to the truncated right arm of LG I. I report here that, in partial diploid strains derived from T(I;V)AR190, large terminal deletions result from chromosome breakage in the NOR. In most of these partial diploids, chromosome breakage is apparently frequent and the breakpoints occur in many parts of the NOR. The rDNA ends resulting from chromosome breakage are ``healed'' by the addition of new telomeres. Significantly, the presence of ectopic rDNA creates a new site of chromosome breakage in the genome of partial diploids. These results raise the possibility that, under certain conditions, rDNA is a region of fragility in eukaryotic chromosomes.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adam R. D., Nash T. E., Wellems T. E. Telomeric location of Giardia rDNA genes. Mol Cell Biol. 1991 Jun;11(6):3326–3330. doi: 10.1128/mcb.11.6.3326. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Blackburn E. H. The molecular structure of centromeres and telomeres. Annu Rev Biochem. 1984;53:163–194. doi: 10.1146/annurev.bi.53.070184.001115. [DOI] [PubMed] [Google Scholar]
  3. Butler D. K., Metzenberg R. L. Expansion and contraction of the nucleolus organizer region of Neurospora: changes originate in both proximal and distal segments. Genetics. 1990 Oct;126(2):325–333. doi: 10.1093/genetics/126.2.325. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Butler D. K., Metzenberg R. L. Premeiotic change of nucleolus organizer size in Neurospora. Genetics. 1989 Aug;122(4):783–791. doi: 10.1093/genetics/122.4.783. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chu G., Vollrath D., Davis R. W. Separation of large DNA molecules by contour-clamped homogeneous electric fields. Science. 1986 Dec 19;234(4783):1582–1585. doi: 10.1126/science.3538420. [DOI] [PubMed] [Google Scholar]
  6. Hecht F., Sutherland G. R. Fragile sites and cancer breakpoints. Cancer Genet Cytogenet. 1984 Jun;12(2):179–181. doi: 10.1016/0165-4608(84)90132-8. [DOI] [PubMed] [Google Scholar]
  7. McClintock B. The Behavior in Successive Nuclear Divisions of a Chromosome Broken at Meiosis. Proc Natl Acad Sci U S A. 1939 Aug;25(8):405–416. doi: 10.1073/pnas.25.8.405. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. McClintock B. The Stability of Broken Ends of Chromosomes in Zea Mays. Genetics. 1941 Mar;26(2):234–282. doi: 10.1093/genetics/26.2.234. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Newmeyer D., Galeazzi D. R. The Instability of Neurospora Duplication Dp(IL-->IR)H4250 , and Its Genetic Control. Genetics. 1977 Mar;85(3):461–487. doi: 10.1093/genetics/85.3.461. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Perkins D. D., Barry E. G. The cytogenetics of Neurospora. Adv Genet. 1977;19:133–285. doi: 10.1016/s0065-2660(08)60246-1. [DOI] [PubMed] [Google Scholar]
  11. Perkins D. D., Metzenberg R. L., Raju N. B., Selker E. U., Barry E. G. Reversal of a Neurospora translocation by crossing over involving displaced rDNA, and methylation of the rDNA segments that result from recombination. Genetics. 1986 Nov;114(3):791–817. doi: 10.1093/genetics/114.3.791. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Perkins D. D., Raju N. B., Barry E. G. A chromosome rearrangement in Neurospora that produces segmental aneuploid progeny containing only part of the nucleolus organizer. Chromosoma. 1984;89(1):8–17. doi: 10.1007/BF00302344. [DOI] [PubMed] [Google Scholar]
  13. Russell P. J., Wagner S., Rodland K. D., Feinbaum R. L., Russell J. P., Bret-Harte M. S., Free S. J., Metzenberg R. L. Organization of the ribosomal ribonucleic acid genes in various wild-type strains and wild-collected strains of Neurospora. Mol Gen Genet. 1984;196(2):275–282. doi: 10.1007/BF00328060. [DOI] [PubMed] [Google Scholar]
  14. Schechtman M. G. Characterization of telomere DNA from Neurospora crassa. Gene. 1990 Apr 16;88(2):159–165. doi: 10.1016/0378-1119(90)90027-o. [DOI] [PubMed] [Google Scholar]
  15. Schechtman M. G. Isolation of telomere DNA from Neurospora crassa. Mol Cell Biol. 1987 Sep;7(9):3168–3177. doi: 10.1128/mcb.7.9.3168. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Sogin M. L., Miotto K., Miller L. Primary structure of the Neurospora crassa small subunit ribosomal RNA coding region. Nucleic Acids Res. 1986 Dec 9;14(23):9540–9540. doi: 10.1093/nar/14.23.9540. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Turner B. C. Euploid derivatives of duplications from a translocation in neurospora. Genetics. 1977 Mar;85(3):439–460. doi: 10.1093/genetics/85.3.439. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Vollrath D., Davis R. W. Resolution of DNA molecules greater than 5 megabases by contour-clamped homogeneous electric fields. Nucleic Acids Res. 1987 Oct 12;15(19):7865–7876. doi: 10.1093/nar/15.19.7865. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Yao M. C., Yao C. H., Monks B. The controlling sequence for site-specific chromosome breakage in Tetrahymena. Cell. 1990 Nov 16;63(4):763–772. doi: 10.1016/0092-8674(90)90142-2. [DOI] [PubMed] [Google Scholar]
  20. Yao M. C., Zheng K., Yao C. H. A conserved nucleotide sequence at the sites of developmentally regulated chromosomal breakage in Tetrahymena. Cell. 1987 Mar 13;48(5):779–788. doi: 10.1016/0092-8674(87)90075-4. [DOI] [PubMed] [Google Scholar]
  21. Yunis J. J. The chromosomal basis of human neoplasia. Science. 1983 Jul 15;221(4607):227–236. doi: 10.1126/science.6336310. [DOI] [PubMed] [Google Scholar]
  22. Zakian V. A. Structure and function of telomeres. Annu Rev Genet. 1989;23:579–604. doi: 10.1146/annurev.ge.23.120189.003051. [DOI] [PubMed] [Google Scholar]

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