Skip to main content
NCBI home page
Genetics logoLink to Genetics
. 1998 Jun;149(2):1105–1113. doi: 10.1093/genetics/149.2.1105

Position effects of ribosomal RNA multigene loci on meiotic recombination in wheat.

M C Luo 1, Z L Yang 1, J Dvorák 1
PMCID: PMC1460165  PMID: 9611218

Abstract

Homeologous wheat chromosome arms that differ by the presence or absence of a Nor locus or greatly differ in the numbers of copies of rRNA genes per Nor locus show conspicuous differences in the distribution of recombination. To assess directly the position effects of Nor loci on recombination across chromosome arms, a Triticum monococcum Nor9 haplotype was substituted for Triticum aestivum Nor9 haplotypes on two T. aestivum 1A chromosomes in the isogenic background of cv Chinese Spring. The numbers of rRNA genes in the 1A Nor9 haplotypes are greatly reduced relative to the T. monococcum haplotype. The substitution resulted in reduced recombination rate in the vicinity of the Nor9 locus. An intra-arm compensatory increase was observed in the proximal region of the arm so that the genetic length of the chromosome arm was unchanged. These findings suggest that Nor loci suppress recombination in their vicinity and change recombination patterns in Nor-bearing chromosome arms.

Full Text

The Full Text of this article is available as a PDF (258.4 KB).

Selected References

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

  1. Coen E. S., Thoday J. M., Dover G. Rate of turnover of structural variants in the rDNA gene family of Drosophila melanogaster. Nature. 1982 Feb 18;295(5850):564–568. doi: 10.1038/295564a0. [DOI] [PubMed] [Google Scholar]
  2. Dubcovsky J., Dvorák J. Ribosomal RNA multigene loci: nomads of the Triticeae genomes. Genetics. 1995 Aug;140(4):1367–1377. doi: 10.1093/genetics/140.4.1367. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dubcovsky J., Luo M. C., Zhong G. Y., Bransteitter R., Desai A., Kilian A., Kleinhofs A., Dvorák J. Genetic map of diploid wheat, Triticum monococcum L., and its comparison with maps of Hordeum vulgare L. Genetics. 1996 Jun;143(2):983–999. doi: 10.1093/genetics/143.2.983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dubcovsky J., Luo M., Dvorak J. Differentiation between homoeologous chromosomes 1A of wheat and 1Am of Triticum monococcum and its recognition by the wheat Ph1 locus. Proc Natl Acad Sci U S A. 1995 Jul 3;92(14):6645–6649. doi: 10.1073/pnas.92.14.6645. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dvorák J., Appels R. Investigation of Homologous Crossing over and Sister Chromatid Exchange in the Wheat Nor-B2 Locus Coding for Rrna and Gli-B2 Locus Coding for Gliadins. Genetics. 1986 Aug;113(4):1037–1056. doi: 10.1093/genetics/113.4.1037. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dvorák J., Chen K. C. Distribution of Nonstructural Variation between Wheat Cultivars along Chromosome Arm 6Bp: Evidence from the Linkage Map and Physical Map of the Arm. Genetics. 1984 Feb;106(2):325–333. doi: 10.1093/genetics/106.2.325. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Forde B. G., Kreis M., Williamson M. S., Fry R. P., Pywell J., Shewry P. R., Bunce N., Miflin B. J. Short tandem repeats shared by B- and C-hordein cDNAs suggest a common evolutionary origin for two groups of cereal storage protein genes. EMBO J. 1985 Jan;4(1):9–15. doi: 10.1002/j.1460-2075.1985.tb02310.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gerlach W. L., Bedbrook J. R. Cloning and characterization of ribosomal RNA genes from wheat and barley. Nucleic Acids Res. 1979 Dec 11;7(7):1869–1885. doi: 10.1093/nar/7.7.1869. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Jiang J., Gill B. S. New 18S.26S ribosomal RNA gene loci: chromosomal landmarks for the evolution of polyploid wheats. Chromosoma. 1994 Jun;103(3):179–185. doi: 10.1007/BF00368010. [DOI] [PubMed] [Google Scholar]
  10. John B., Miklos G. L. Functional aspects of satellite DNA and heterochromatin. Int Rev Cytol. 1979;58:1–114. doi: 10.1016/s0074-7696(08)61473-4. [DOI] [PubMed] [Google Scholar]
  11. LONGWELL A. C., SVIHLA G. Specific chromosomal control of the nucleolus and of the cytoplasm in wheat. Exp Cell Res. 1960 Aug;20:295–312. doi: 10.1016/0014-4827(60)90159-2. [DOI] [PubMed] [Google Scholar]
  12. Lander E. S., Green P., Abrahamson J., Barlow A., Daly M. J., Lincoln S. E., Newberg L. A., Newburg L. MAPMAKER: an interactive computer package for constructing primary genetic linkage maps of experimental and natural populations. Genomics. 1987 Oct;1(2):174–181. doi: 10.1016/0888-7543(87)90010-3. [DOI] [PubMed] [Google Scholar]
  13. Loidl J. The initiation of meiotic chromosome pairing: the cytological view. Genome. 1990 Dec;33(6):759–778. doi: 10.1139/g90-115. [DOI] [PubMed] [Google Scholar]
  14. Petes T. D. Unequal meiotic recombination within tandem arrays of yeast ribosomal DNA genes. Cell. 1980 Mar;19(3):765–774. doi: 10.1016/s0092-8674(80)80052-3. [DOI] [PubMed] [Google Scholar]
  15. ROBERTS P. A. DIFFERENCE IN THE BEHAVIOR OF EU- AND HETERO-CHROMATIN: CROSSING-OVER. Nature. 1965 Feb 13;205:725–726. doi: 10.1038/205725b0. [DOI] [PubMed] [Google Scholar]
  16. Ranzani G. N., Bernini L. F., Crippa M. Inheritance of rDNA spacer length variants in man. Mol Gen Genet. 1984;196(1):141–145. doi: 10.1007/BF00334106. [DOI] [PubMed] [Google Scholar]
  17. Williams S. M., Robbins L. G. Molecular genetic analysis of Drosophila rDNA arrays. Trends Genet. 1992 Oct;8(10):335–340. doi: 10.1016/0168-9525(92)90277-b. [DOI] [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES