Abstract
The rRNA genes are the most accessible genes for the study of gene expression at a molecular, structural, and ultrastructural level. This paper describes the occurrence and distribution of rRNA genes in wheat, barley and rye. These cereal species are closely related and intercrossable but the rRNA genes show only a very loose conservation to chromosomes of the same homoeologous group which is surprising considering the close co-linearity of single copy markers. The cereals have an apparent excess in the number of genes required to sustain ribosome synthesis. Some of the “redundant” genes may occur in inactive rDNA loci that are not associated with a nucleolus. Factors affecting locus suppression are reviewed. Loci involved in rDNA transcription include regions that contain actively transcribing genes and regions that contain inactive genes. The active genes are probably associated with the dense fibrillar component of the nucleolus, while the inactive genes remain condensed. In rye, the condensed, inactive genes occur in perinucleolar chromatin and the active genes are decondensed at the distal end of the rDNA locus. In wheat condensed genes occur inside and outside the nucleolus with each active locus showing several sites with decondensed genes separated by condensed, intranucleolar presumably inactive genes. In rye and wheat active rDNA loci extend through the nucleolus and active rDNA sequences do not loop out from perinucleolar chromatin.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Anamthawat-Jónsson, K. and Heslop-Harrison, J.S. (1990) Centromeres, telomeres and chromatin in the interphase nucleus of cereals. Caryologia 43, 205–213.
Appels, R., Gerlach, W.L., Dennis, E.S., Swift, H. and Peacock, W.J. (1980) Molecular and chromosomal organization of DNA sequences coding for ribosomal RNAs in cereals. Chromosoma 78, 293–311.
Appels, R. and Honeycut, R.L. (1986) rDNA: evolution over a billion years, in DNA Systematics Volume II: Plants, (ed Dutta, S.K.), CRC Press, Florida, pp.81–135.
Bennett, M.D. (1984) Nuclear architecture and its manipulation, in Gene manipulation in plant improvement (ed Gustafson JP), Plenum Publishing Corporation, New York, pp. 469–502.
Buescher, P.J., Phillips, R.L. and Brambl, R. (1984) Ribosomal RNS contents of maize genotypes with different ribosomal RNA gene numbers. Biochem. Genet. 22, 923–930.
Deltour, R. and Motte, P. (1990) The nucleolonema of plant and animal cells: a comparison. Biol. Cell 68, 5–11.
Devos, K.M., Atkinson, M.D., Chinoy, C.N., Liu, C.J. and Gale, M.D. (1992) RFLP-based genetic map of the homoeolgous group 3 chromosomes of wheat and rye. Theor. Appl. Genet. 83, 931–939.
Dvorák, J. and Appels, R. (1982) Chromosome and nucleotide sequence differentiation in genomes of polyploid Triticum species. Theor. Appl. Genet. 63, 349–360
Flavell, R.B. (1986) The structure and control of expression of ribosomal RNA genes. Oxford Surveys of Plant Mol. and Cell Biol. 3, 252–274.
Flavell, R.B. (1989) Variation in structure and expression of ribosomal DNA loci in wheat. Genome 31, 963–968.
Flavell, R.B. and O’Dell, M. (1990) Variation and inheritance of cytosine methylation patterns in wheat at the high molecular weight glutenin and ribosomal RNA gene loci. Development Supplement, 15–20.
Flavell, R.B., O’Dell, M. and Thompson, W.F. (1988) Regulation of cytosine methylation in ribosomal DNA and nucleolus organizer expression in wheat. J. Mol. Biol. 204, 523–534.
Gerlach, W.L. and Bedbrook, J.R. (1979) Cloning and characterization of ribosomal RNA genes from wheat and barley. Nuc. Acids Res. 7, 1869–1885.
Goessens, G. (1984) Nucleolar structure. Int. Rev. Cytol. 87, 107–158.
Gustafson, J.P., Dera, A.R. and Petrovic, S. (1988) Expression of modified rye ribosomal RNA genes in wheat. Proc. Natl. Acad. Sci. USA 85, 3943–3945.
Hernandez-Verdun, D. (1991) The nucleolus today. J. Cell Sci. 99, 465–471.
Jordan, E.G., Martini, G., Bennett, M.D. and Flavell, R.B. (1982) Nucleolar fusion in wheat. J. Cell Sci. 56, 485–495.
Lacadena, J.R., Cremeño, M.C., Orellana, J. and Santos, J.L. (1988) Nucleolar Competion in Triticeae, in Kew Chromosome Conference III. (ed. Brandham P.E.), HMSO, London, pp. 151–165.
Leitch, I.J. and Heslop-Harrison, J.S. (1992) Physical mapping of 18S-5.8S–26S rRNA genes in barley by in situ hybridization. Genome (in press).
Leitch, A.R., Mosgöller, W., Shi, M. and Heslop-Harrison, J.S. (1992) Different patterns of rDNA organization at interphase in nuclei of wheat and rye. J. Cell Sci. 101, 751–757.
Leitch, A.R., Schwarzacher, T., Mosgöller, W., Bennett, M.D. and Heslop-Harrison, J.S. (1991) Parental genomes are separated throughout the cell cycle in a plant hybrid. Chromosoma 101, 206–213.
Martini, G., O’Dell, M and Flavell, R.B. (1982) Partial inactivation of wheat nucleolar organisers by the nucleolus organiser chromosomes from Aegilops umbellulata. Chromosoma 84, 687–700.
Manuelidis, L. and Borden, J. (1988) Reproducible compartmentalization of individual chromosome domains in human CNS cells revealed by in situ hybridization and three-dimensional reconstruction. Chromosoma 96, 397–410.
Martini, G. and Flavell, R.B. (1985) The control of nucleolus volume in wheat, a genetic study at three developmental stages. Heredity 54, 111–120.
Nicoloff, H., Anastassova-Kristeva, M., Rieger, R., and Künzel G. (1979) ‘Nucleolar dominance’ as observed in barley translocation lines with specifically reconstructed SAT chromosomes. Theor. Appl. Genet. 55, 247–251.
Moreno, F.J., Rodrigo, R.M. and Garcia-Herdugo, G. (1990) Ag-NOR proteins and rDNA transcriptional activity in plant cells. J. Histochem. Cytochem. 38, 1879–1887.
Mukai, Y., Endo, T.R. and Gill, B.S. (1991) Physical mapping of the 18S.26S rRNA multigene family in common wheat: Identification of a new locus. Chromosoma 100, 71–78.
Nomura, M., Gourse, R. and Baughman, G. (1984) Regulation of the synthesis of ribosomes and ribosomal components. Ann. Rev. Biochem. 53, 75–117.
Rabl, C. (1885) Über Zelltheilung. Morphol. Jahrb. 10, 214–330.
Risueflo M.C. and Medina F.J. (1986) The nucleolar structure in plant cells. Cell Biology Reviews (RBC) 7, 1–154.
Rogers, S.O. and Bendich, A.J. (1987a) Heritability and Variability in ribosomal RNA genes of Vicia faba. Genetics 117, 285–295.
Rogers, S.O., and Bendich, A.J. (1987b) Ribosomal RNA genes in plants: variability in copy number and in the intergenic spacer. Plant Mol. Biol. 9, 509–520.
Schwarzacher, H.G., and Wachtler, F. (1986) Nucleolus organizer regions and nucleoli: Cytological findings. Chromosomes Today 9, 252–260.
Vieira, R., Queiroz, A., Morais, L., Barao, A., MelloSampayo, T. and Viegas, W. (1990a) 1R chromosome nucleolus organizer region activation by 5-azacytidine in wheat x rye hybrids. Genome 33, 707–712.
Vieira, R., Queiroz, A., Morais, L., Barao, A., MelloSampayo, T. and Viegas, W. (1990b) Genetic control of 1R nucleolus organizer region expression in the presence of wheat genomes. Genome 33, 713–718.
Williams, E., Heslop-Harrison, J. and Dickinson, H.G. (1973) The activity of the nucleolus organising region and the origin of cytoplasmic nucleoloids in meiocytes of Lilium. Protoplasma 77, 79–93.
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 1993 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
Leitch, A.R., Heslop-Harrison, J.S. (1993). Ribosomal RNA gene expression and localization in cereals. In: Chromosomes Today. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-1510-0_7
Download citation
DOI: https://doi.org/10.1007/978-94-011-1510-0_7
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-4660-2
Online ISBN: 978-94-011-1510-0
eBook Packages: Springer Book Archive