Standard Article

Nucleolar Dominance

  1. Craig S Pikaard

Published Online: 27 JAN 2006

DOI: 10.1038/npg.els.0005976



How to Cite

Pikaard, C. S. 2006. Nucleolar Dominance. eLS. .

Author Information

  1. Washington University, Saint Louis, Missouri, USA

Publication History

  1. Published Online: 27 JAN 2006

This is not the most recent version of the article. View current version (15 JAN 2014)


Nucleolar dominance is an epigenetic phenomenon in plant and animal hybrids that describes the failure to form nucleoli, the sites of ribosome synthesis, on chromosomes inherited from one parent. The molecular basis for nucleolar dominance is the reversible silencing of ribosomal RNA genes transcribed by RNA polymerase I. These genes are clustered at loci spanning millions of base pairs, making nucleolar dominance one of the most extensive known chromosomal-silencing phenomena.


  • gene silencing;
  • epigenetic phenomena;
  • ribosomal RNA;
  • RNA polymerase I;
  • nucleolus organizer