Elimination of chromosomes in Hordeum vulgare × H. bulbosum crosses at mitosis and interphase involves micronucleus formation and progressive heterochromatinizationGernand D.a · Rutten T.a · Pickering R.b · Houben A.a
aInstitute of Plant Genetics and Crop Plant Research (IPK), Gatersleben (Germany);aNew Zealand Institute for Crop & Food Research Limited, Christchurch (New Zealand)
Uniparental chromosome elimination occurs in several interspecific hybrids of plants. We studied the mechanism underlying selective elimination of the paternal chromosomes during the development of Hordeum vulgare × H. bulbosum hybrid embryos that is restricted to an early stage of development. In almost all embryos most of the H. bulbosum chromatin undergoes a fast rate of elimination within nine days after pollination. There are differences in the mitotic behaviour between the parental chromosomes, with H. bulbosum chromatids segregating asymmetrically at anaphase. We provide evidence for a chromosome elimination pathway that involves the formation of nuclear extrusions during interphase in addition to postmitotically formed micronuclei. The chromatin structure of nuclei and micronuclei differs and heterochromatinization and disintegration of the nuclear envelope of micronuclei are the final steps of chromosome elimination.
© 2006 S. Karger AG, Basel
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This work was supported by the Bundesministerium für Bildung und Forschung (Berlin, Germany) and the Icon Genetics GmbH (Halle, Germany).
Manuscript received: 29 August 2005
Accepted in revised form for publication by M. Schmid,: 23 November 2005.
Number of Print Pages : 6
Number of Figures : 4, Number of Tables : 0, Number of References : 24
Cytogenetic and Genome Research
Vol. 114, No. 2, Year 2006 (Cover Date: July 2006)
Journal Editor: Schmid, M. (Würzburg)
ISSN: 1424–8581 (print), 1424–859X (Online)
For additional information: http://www.karger.com/CGR