Cloning and characterisation of polymorphic heterochromatic segments of Brachycome dichromosomatica
Date
2000
Authors
Houben, A.
Wanner, G.
Hanson, L.
Verlin, D.
Leach, C.
Timmis, J.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Chromosoma, 2000; 109(3):206-213
Statement of Responsibility
Houben, Andreas ; Wanner, Gerhard ; Hanson, Lynda ; Verlin, Dawn ; Leach, Carolyn ; Timmis, Jeremy
Conference Name
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.