Chromosoma

, Volume 109, Issue 3, pp 206–213 | Cite as

Cloning and characterisation of polymorphic heterochromatic segments of Brachycome dichromosomatica

  • Andreas Houben
  • Gerhard Wanner
  • Lynda Hanson
  • Dawn Verlin
  • Carolyn R. Leach
  • Jeremy N. Timmis

Abstract.

After selective enrichment and differential hybridisation of Cot-1 DNA fractions of plants with and without polymorphic heterochromatic segments, a repetitive sequence (called Bds1) specific to the polymorphic chromosome segments of Brachycome dichromosomatica (Brachyscome dichromosomatica) was isolated. A single repeat unit of Bds1 is 92 bp long and is organised in tandem arrays at three different polymorphic segment sites on the chromosomes of cytodeme A2. Although all three sites showed extensive polymorphism between plants, the karyotypes of all analysed mitotic root cells were stable within a single plant. Electron microscopy revealed heavily condensed chromatin structures at the most obvious polymorphic site. The mechanisms that generate and maintain the observed chromosome structure polymorphisms are discussed.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Andreas Houben
    • 1
  • Gerhard Wanner
    • 2
  • Lynda Hanson
    • 3
  • Dawn Verlin
    • 1
  • Carolyn R. Leach
    • 1
  • Jeremy N. Timmis
    • 1
  1. 1.Department of Genetics, The University of Adelaide, Adelaide, South Australia 5005, AustraliaAU
  2. 2.Botanisches Institut der Universität München, Menzingerstrasse 67, 80638 München, GermanyDE
  3. 3.Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UKGB

Personalised recommendations