Chromosome Research

, Volume 3, Issue 7, pp 417–422

Stable chromosome fission associated with rDNA mobility

Authors

    • the Department of Botany, School of Plant SciencesUniversity of Reading, Whiteknights
  • J. S. Parker
    • the Department of Botany, School of Plant SciencesUniversity of Reading, Whiteknights
Article

DOI: 10.1007/BF00713891

Cite this article as:
Hall, K.J. & Parker, J.S. Chromosome Res (1995) 3: 417. doi:10.1007/BF00713891

Abstract

A spontaneous chromosome fission in the plantHypochoeris radicata has been characterized by Feulgen staining,in situ hybridization of the rDNA probe pTA71 and silver staining for active nucleolus organizing regions. The parental acrocentric chromosome has no detectable ribosomal genes at the centromere, but both fission derivatives possess active NORs at their centric ends. In fission heterozygotes, pachytene configurations studied by synaptonemal complex spreading show that the ribosomal cistrons form short arms on each telocentric which pair together to form a triradial. The paired short arms are associated with the single nucleolus at pachytene. It is proposed that the origin and stabilization of the fission rearrangement involved transposition of rDNA from the nucleolus organizing region of chromosome 3 into the centromeric region of chromosome 1.

Key words

chromosome fissionNORNOR movementrDNA

Copyright information

© Rapid Communications of Oxford Ltd 1995