Mechanisms of genomic rearrangements and gene expression changes in plant polyploids

Authors

  • Z. Jeffrey Chen,

    Corresponding author
    1. Molecular Cell and Developmental Biology, University of Texas, Austin, TX USA
    • Institute for Cellular and Molecular Biology, University of Texas at Austin, 1 University Station, A-4800, Austin, TX 78714-0159.
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  • Zhongfu Ni

    1. Molecular Cell and Developmental Biology, University of Texas, Austin, TX USA
    2. Department of Plant Genetics and Breeding, China Agricultural University, Beijing, China
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Abstract

Polyploidy is produced by multiplication of a single genome (autopolyploid) or combination of two or more divergent genomes (allopolyploid). The available data obtained from the study of synthetic (newly created or human-made) plant allopolyploids have documented dynamic and stochastic changes in genomic organization and gene expression, including sequence elimination, inter-chromosomal exchanges, cytosine methylation, gene repression, novel activation, genetic dominance, subfunctionalization and transposon activation. The underlying mechanisms for these alterations are poorly understood. To promote a better understanding of genomic and gene expression changes in polyploidy, we briefly review origins and forms of polyploidy and summarize what has been learned from genome-wide gene expression analyses in newly synthesized auto-and allopolyploids. We show transcriptome divergence between the progenitors and in the newly formed allopolyploids. We propose models for transcriptional regulation, chromatin modification and RNA-mediated pathways in establishing locus-specific expression of orthologous and homoeologous genes during allopolyploid formation and evolution. BioEssays 28: 240–252, 2006. © 2006 Wiley Periodicals, Inc.

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