Chromosome Research

, Volume 3, Issue 8, pp 487–491 | Cite as

The influence of B chromosomes on rDNA organization in rye interphase nuclei

  • M. Delgado
  • L. Morais-Cecílio
  • N. Neves
  • R. N. Jones
  • W. Viegas


Patterns of rye rDNA organization in interphase nuclei were studied through the use ofin situ hybridization in spreads of root meristem cells from plants with and without B chromosomes (Bs). In cells from plants without Bs each rDNA locus is organized as a single perinucleolar knob of condensed chromatin with decondensed chromatin inside the nucleolus. In plants with Bs there is a marked modification of the pattern, found in more than 23% of nuclei, which involves several regions of condensed chromatin interspersed with decondensed chromatin inside the nucleolus. This B-induced alteration in rDNA interphase organization suggests a change in expression of the rRNA genes located on the A chromosomes probably related to the reduction in nuclear RNA observed previously in plants with Bs. The influence of the Bs on the expression of A chromosome genes, through rearrangement of interphase chromatin, could provide the basis of an explanation for some of the known phenotypic effects of B chromosomes in rye.

Key words

B chromosomes interphase chromatin rDNA organization rye 


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Copyright information

© Rapid Science Publishers 1995

Authors and Affiliations

  • M. Delgado
    • 1
  • L. Morais-Cecílio
    • 1
  • N. Neves
    • 1
  • R. N. Jones
    • 2
  • W. Viegas
    • 1
  1. 1.Departamento de Botânica e Engenharia BiológiaInstituto Superior de AgronomiaLisboa CodexPortugal
  2. 2.The Institute of Biological SciencesUniversity of Wales AberystwythAberystwythWales UK

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